
    The Boston Water Power Company vs. Horace Gray.
    Arbitrators have authority to decide conclusively all questions of law necessary to the decision of the matters submitted to them, unless they are restricted by the terms of the submission, or unless it appears on the face of their award, that they intended to decide according to law, but have decided contrary to law: And there is no distinction, in this respect, between the authority of arbitrators who are selected from the legal profession, and that of other arbitrators.
    The decision of arbitrators, to whom all questions of fact and law are submitted, and who act fairly, is conclusive, unless it can be impeached and avoided by proof of fraud prac-tised on them, or proof of mistake or accident, by which they were deceived and misled, no that their award is not in fact the result of their judgment: But their mistakes in drawing conclusions of fact from evidence or observation, or m adopting erroneous vales of law or theories, of philosophy, are not a legal cause for avoiding their award.
    Hence, where a question as to the measure of a water power, granted by demise, was submitted to arbitrators, and they, after making numerous actual experiments, constructed a table, on hydraulic principles, by which the use of the water was to be osculated3 it was held that evidence was not admissible to show that the table was constructed on erroneous principles.
    The -wners of the water powers at the Boston Mill Dam leased a certain number of mili powers, with an agreement that they would do nothing whereby the power graced might in any way be in anywise defeated or diminished: Disputes afterwards aros-' respecting the quantities of water to which the lessee was entitled, and as to the i*»ode of measuring and delivering the same, and the use thereof} whereupon the partienj submitted the matters in dispute to arbitrators, authorizing them (among other things; to determine what quantities of water the lessee was entitled to draw, by virtue of his lease, and also to determine the manner in which the same should be measured and delivered, and to settle, in all other particulars, the legal rights of the parties under and by virtue of the lease, and to employ such engineers, agents, &c. as they should see fit, for the purpose of enabling them to determine the extent of the water power, and other experimental matters incident to the business committed to them, and to determine what part of the expenses appertaining thereto should be borne by each party. Held, that the arbitrators had not exceeded their authority by awarding that the lessee should take the water at a lower level than that at which it was taken at the time when the lease was made 3 nor by awarding that the lessee should pay Half the expense of an apparatus which they ordered to be made and set up for measuring the water to be received by the lessee, and half the expense of the experiments made by the arbitrators to determine the whole number of mill powers which the lessors owned 3 nor by awarding that the water received by the lessee should be measured after it had passed his mills, and not before. Held also, that the arbitrators had not exceeded their authority by awarding that the lessors should remove accretions from the basin that received the water, whenever it should be necessary to the full enjoyment of the water powers granted to the lessee, although the lessors might not own the soil 5 the arbitrators being of opinion that the lessors had the right and were bound to enter upon the receiving basin, and remove therefrom obstructions arising from accretions. Held farther, that the arbitrators, by awarding that the lessee was entitled to the use and enjoyment of his mill powers “ so long as the basins will furnish the same,” had not, by implication, impaired his rights under the lease which gave him such powers absolutely, and without any limitation.
    This was an action of covenant broken.
    Tn the year 1836, the plaintiffs and the Boston and Roxbury Mill Corporation, of the first part, and' the defendant and the Boston Iron Company, of the second part, made and executed the following indenture:
    “ Whereas the said Bostón and Roxbury Mill Corporation heretofore leased and demised to said Horace Gray, for a term of years yet unexpired, certain water powers and other premises described in certain indentures, made and executed between said Boston and Roxbury Mill Corporation and said Gray; 
      
      and the said Gray has since verbally agreed to assign a portion of the said water powers and other demised premises to the said Boston Iron Company, and has leased other portions of the same to Messrs. Boott and Lyman; and said Boston and Roxbury Mill Corporation, after the making of the said lease to said Gray, and of divers other leases of water power to other persons, sold, assigned and conveyed to the said Boston Water Power Company all the remaining interest of the said Boston and Roxbury Mill Corporation in and to the water power created by the basins and dams of the said last mentioned corporation, together with the said several leases to Horace Gray and others, and all the rents and reservations thereto belonging; and whereas questions and controversies have arisen between the parties to these presents, respecting the quantities of water to which the said Gray, and those claiming under him, are entitled, and the mode of measuring and delivering the same, and respecting the quantities of water which said Gray and others have heretofore in fact used and enjoyed, and otherwise respecting the mutual rights and obligations of the parties in regard to the nature and extent of the water power created by the said basins and dams, and the manner of using the same; and whereas certain suits at law have been commenced by the said Gray, against the said Boston and Roxbury Mill Corporation, for divers alleged breaches of covenant, which suits are yet pending; now, for the purpose of adjusting and finally determining all and singular the said suits, controversies and questions, defining and limiting the mutual rights, powers and obligations of the parties respectively, and regulating and securing the future enjoyment and fulfilment of the same, the said parties have mutually entered into the agreements and stipulations contained in the articles following :
    “First. Three commissioners are and shall be mutually selected and appointed, in the manner and for the purposes hereinafter expressed, of whom one, who is to be chairman of the board, shall be á person learned in the law, and the other two shall be civil engineers, practically skilled in the measurement of water power, and learned in the scientific principles and rules applicable thereto ; and the parties have mutually agreed upon the following persons for such commissioners, if they sha., consent to serve, namely, the Hon. Leverett Saltonstall, to be chairman of the board, and Loammi Baldwin, Esq., of Charles-town, in the county of Middlesex, and James Hayward, Esq., of Cambridge, in said county, to be his associates. And if either of the said associate commissioners shall refuse to serve, or, after accepting, shall become unable to proceed in the business of the said board, or if otherwise a vacancy shall at any time occur therein, excepting in the case of the chairman, the party which had nominated the commissioner so refusing, or becoming unable to proceed, or otherwise creating a vacancy, shall, within ten days after notice of such vacancy, nominate to the other party a suitable person to fill the vacant place; and the other party shall, within three days after written notice of such nomination, signify in writing whether or not the said nomination is agreed to, and it shall be considered as agreed to, unless within the three days the contrary be signified, as aforesaid. And whensoever any commissioner shall be agreed upon between the parties, he shall be forthwith notified of his appointment, by a letter to be signed by both parties jointly, or by their counsel, and no commissioner shall ever be informed by which party ho was first nominated; and if such nomination as aforesaid is negatived within three days, the nominating party shall, within ten days after notice thereof, nominate anew ; and the other party shall, within three days after notice thereof, signify his assent or dissent in manner aforesaid ; but if the party, having the right of nomination as aforesaid, shall fail so to nominate within the time above fixed, or if a second nomination shall have been negatived by the other party, it shall then be competent for the two remaining commissioners either to fill the vacancy themselves, or to proceed in the business of the commission without a third commissioner, as they shall elect. And in case a vacancy shall at any time occur in the place of the chairman, either by his refusal to serve, or by his becoming unable to act, or otherwise, it is agreed that the counsel of the respective parties may appoint a substitute, either permanently, or for the particular exigency, as they shall see fit. And in case the counsel of either party shall, after notice, neglect to act upon the subject for the space of three days, it shall be competent for the counsel of the other party alone, to make such appointment.
    “ Second. It shall be the duty of the said commissioners to determine, as soon as may be, what quantities of water the said Gray, and those claiming under him, are entitled to draw and use, under and by virtue of the said lease from the said Boston and Roxbury Mill Corporation to said Gray, and also to determine the manner in which the same shall be measured and delivered, and to define and settle, in all other particulars, the legal rights of the respective parties under and by virtue of the said lease
    
      “ Third. It shall be the further duty of the said commissioners, to determine whether said Gray has, or has not, heretofore had and enjoyed, at all and at what times, the full use of the powers to him granted in and by the said lease, and whether or not he has, at any and what times, had and enjoyed greater powers than were to him granted and demised, as aforesaid, and to state as nearly as possible, the extent and duration of all such deficiencies and excesses, the times and periods of their occurrence, and the causes thereof, as nearly as the same can be ascertained, from the date of the said lease up to the time when the said commissioners shall make their award, and to decide for what portions and periods of such deficiencies or excesses, either party may have a legal claim for damages against the other: It being however expressly agreed, that neither party is to be debarred, by reason of this submission, from the full effect of any legal or equitable defence before the said commissioners, of which he might avail himself in any suit at law, or in equity, against the claim of the other party for such deficiency or excess, either in the whole, or in respect to any particular portion and period thereof.
    “ Fourth. The said commissioners, having ascertained and defined, are to declare by their award, the legal rights of the parties in respect to the premises, and all other matters submitted to them, including the legal principles by which the damages of either party, if any exist, are to be measured and ascertained : But the said commissioners are not to inquire into ascertain, or declare the amount of damages sustained bj either party in any case, or what sum of money would be a fair pecuniary equivalent and satisfaction therefor ; which matters shall be determined by another board of referees, as hereinafter provided.
    “Fifth. The said Boston and Roxbury Mill Corporation and the said Boston Water Power Company shall not, pending this submission, nor until the final award of the said commissioners, use or lease any more powers than now are, or heretofore have been, used or leased, nor license any encroachments, whether now existing or not, upon either of their basins, without first submitting to the said commissioners, after due notice to said Gray, the right or propriety thereof, nor without the previous authority and permission of the commissioners respecting such license, and upon such terms only as they shall prescribe ; but it is expressly understood and agreed, that the commission ers may authorize the granting of such lease or license, if they shall see fit, on such terms as they shall deem equitable between the parties; and their decision on any such matter shall be conclusive upon the parties, until the publication of their final award, or until they shall otherwise order; and nothing herein shall be considered a waiver by said Gray of any claim he may have in consequence of any past leases or encroachments, if any such exist, nor an admission by the other party that he has any claim on account of the premises, or that any such encroachment exists.
    “ Sixth. If the said commissioners, after hearing the parties, shall find, as a determinate fact, that said Gray and his assigns have not had at all times the full quantity of water, to which he and they are entitled, under and by virtue of the said lease, the said commissioners, if they see fit, shall, on application of either party, prescribe and direct to what extent and in what manner the said Boston Water Power Company (not including, however, present lessees) may draw and use the water at such times of deficiency, so as to preserve to said Gray, or those claiming under him, as nearly as may be, the full use of the powers to which he and they are entitled, under and by virtue of said lease ; and such prescription or direction shall be binding upon the parties, until the commissioners shall otherwise order; or, in default thereof, until the publication of their final award.
    “ Seventh. The final award of the commissioners, upon all matters submitted to them, shall be in duplicate writings, by them subscribed, sealed up, and directed to the counsel of the respective parties, and to them delivered within twelve months from the day of the first meeting of the commissioners, unless a further extension of time shall have been previously requested and agreed to ; and the said award shall be final and conclusive between the parties, upon all matters embraced therein, unde? this submission, and each party shall specifically perform whatsoever shall be therein awarded to be by such party specifically performed, so far as the same has been submitted as aforesaid.
    “ Eighth. The said commissioners shall have full power to employ such engineers, surveyors, and other agents, servants and assistants, as they shall see fit, for the purpose of enabling them to determine the extent of the water power and other experimental matters, incident to the business of the said commission ; and they shall determine and award what portion of the expenses appertaining thereto, exclusive of their own compen - sation and ordinary expenses of reference, shall be borne by each party. But the compensation of the commissioners themselves, and the ordinary expenses of reference, shall be divided equally between the parties, one half to each.
    “ Ninth. The foregoing submission, and the award that may be consequent thereon, are not to affect in any way the rights of either party as against third persons; it being however understood and agreed, that said Gray represents and undertakes to bind, by the said submission and award, all persons claiming through him under his said lease from the Boston and Roxbury Mill Corporation, except Messrs. Boott and Lyman, and those claiming under them, whom he does not represent, nor undertake to bind in the premises.
    “ Tenth. After the publication of the award of the said commissioners, touching all matters submitted to them, the first of the several suits commenced by said Gray against the Boston and Roxbury Mill Corporation, and now pending in the supreme ju licial court for the county of Suffolk, for the recovery of damages by reason of the several breaches of covenant therein alleged, shall be submitted, together with all other claims of either party upon the other for damages, (excepting the claim of the said Gray under and by virtue of his second suit against the laid corporation,) to the arbitrament and award of three disinterested referees mutually chosen, of whom the chairman shall be a person learned in the law; and the said referees, after hearing the parties, shall determine and award what amount of pecuniary damages, if any, either party shall be entitled to recover and receive from the other, for any cause whatsoever, (excepting the second suit of said Gray, as before excepted,j conformably to the principles, and respective legal rights of the parties, as ascertained and established by the previous award of the commissioners above named; which award is to be absolutely conclusive in this second reference, as to all matters which the said award purports to determine. And the second of the said suits commenced by the said Gray, and now pending as aforesaid, against the said Boston and Roxbury Mill Corporation, for the recovery of damages by reason of the several breaches of covenant therein alleged, shall also be submitted, but by a separate and distinct instrument of submission, to the arbitrament and award of the same referees ; who, after hearing the parties, shall determine and separately award what amount of pecuniary damages, if any, the said Gray is entitled to recover in his said second suit, conformably to the principles, and legal rights of the respective parties, as ascertained and established in and by the previous award of the commissioners aforesaid, which award is to be absolutely conclusive, in this last mentioned reference also, as to all matters which the said award purports to determine. And each of the said several awards of the said second set of referees, touching the subject of pecuniary damages, shall be made in duplicate writings by them subscribed, sealed up, and delivered to the counsel of the respective parties within three months after their first meeting. The chairman of this second reference shall be appointed by the counsel of the respective parties, or the counsel of one of them alone upon neglect of the other to act, in like manner as is above provided in case of a vacancy in the office of chairman in the board of commissioners aforesaid. And [a blank was here left for the names] are now agreed upon between the parties for the other referees; and in case of the refusal or inability of either of them to act, or of a vacancy otherwise occurring, such vacancy shall be filled in the same manner as is above provided of and concerning the filling of vacancies in the board of commissioners aforesaid; and all the members of the said second reference shall be notified of their appointment by the joint letter of the parties, or their counsel, and no one of the said referees shall be informed by whom he was first nominated.
    “ Eleventh. The award of any two of the said board of commissioners, the third commissioner dissenting, and the award of any two of the said second set of referees, the third referee dissenting, shall be regarded, to all intents and purposes, as the award of the whole.
    “ Twelfth. It shall be competent for the said second set of referees to inquire into, settle and determine, any principle of law which shall be necessary for the ascertaining and settling of legal damages between the parties, any thing herein to the contrary notwithstanding; provided such principle of law is not embraced in and determined by the previous award of the commissioners aforesaid, and is not in any respect repugnant to, or conflicting with, the principles established by the report and award of said commissioners, which are to govern as aforesaid in all matters therein embraced. And the several corporations and persons, parties to these presents, hereby severally covenant, each with the other, well and truly to observe, keep and fulfil all and singular the said articles of' agreement, and all and singular the stipulations and undertakings by them respectively to be observed, kept and fulfilled, according to the true intent and meaning of these presents.
    “ In witness whereof, the said Boston and Ttoxbury Mill Corporation and the said Boston Water Power Company, of the one part, by their respective presidents, duly authorized thereto, have hereunto set their respective corporate seals; and of the other part, the said Horace Gray hath hereunto set his hand and seal, and the said Boston Iron Company hath also hereunto set its corporate seal by the said Horace Gray, thereto duly authorized; and the said parties have interchangeably delivered these presents.”
    It was afterwards agreed between the parties to the above indenture, that the time for making and publishing the award of said commissioners should be extended to such time as they might find necessary, not beyond the first day of October 1838, and that the said award, then made and published, should have the same effect as if made and published within the time originally prescribed
    
      On the 29th of September 1838, the commissioners made and published their award, as follows — after setting forth the terms of the submission, and the subsequent agreement of the parties to enlarge the time of making and publishing it:
    “ Whereas, during the pendency of this commission, the said Loammi Baldwin has deceased, and the said parties did not fill the vacancy thereby caused in the said board of commission ers; and the said Saltonstall and Hayward, according to the provisions of said indenture in such case, did elect to proceed in the business of the said commission, and to complete the same, without a third commissioner. And whereas the said Salton-stall, Baldwin and Hayward, in the life time of the said Baldwin, and the said Saltonstall and Hayward, since his decease, have fully heard, examined and considered the allegations, witnesses and evidence of the said parties, and their counsel, concerning the premises aforesaid, and all the controversies and questions submitted to the said board of commissioners as aforesaid; and have, with the assistance of other persons em ployed by them, made the surveys, examinations, and experiments, necessary to enable them to determine the extent of water power, and the rights of the said parties, as submitted to them by the said indenture: That is to say, after hearing the said parties, the said commissioners proceeded to make a careful examination of the tides in Charles River, and the effect of the tides upon the full and receiving basins of the said Boston Water Power Company, for the purpose of ascertaining the quantity of water that may be drawn from the full basin, in every variety of tides, and the head and fall under which this vaiying quantity of water may be used in the various states of the basins. They also made a series of experiments, by which they ascertained the quantity of water which, in every variety of height of the two basins, constitutes a mid power, according to the description and definition thereof in the said lease; and also the quantity of water which the said Gray, and those claiming under him, are entitled to draw, under every variety of head and fall. And from their observations of the tides, and the experiments made by them in grinding, the said commissioners ascertained and determined the number of mill powers which the said basins will afford, at any and every tide. The said commissioners also inquired into the quantity and amount of work done at the iron works erected and established by said Gray on the leased premises, and measured the quantity of water used in doing the said work, whereby they determined, as nearly as the same could be ascertained, the quantity of water generally used at the said iron works.
    “ And now the said Leverett Saltonstall and James Hayward, surviving commissioners as aforesaid, do hereby make this their final award and determination upon all matters and questions submitted to them by the said indenture, in manner and form following: That is to say,
    “ First: The said commissioners find that the number of cubic feet of water per second, which constitutes a mill power, for each head or height of water in the full basin, and for every tenth of a foot of back water or height of the empty basin, above the bottom of the south wheel in the mills belonging to the said Boston Water Power Company, called the * City Mills,’ is as set forth in the table hereinafter contained, showing the cubic feet of water required per second for a mill power, with the different heights of water in the two basins. And they do award and order, that the said Horace Gray, and those claiming under him, are, by virtue of said lease, entitled to, and may at all times draw and use, at the said iron works or mills on the premises leased to said Gray as aforesaid, at any head or height of water in the full basin, and with any quantity of back water in the empty basin, eight times the quantity, or number of cubic feet of water per second, which in the said table corresponds to those several heights in the said two basins. The explanation of the said table is as follows, namely:
    “The first column gives the head or height of the water above the bottom of the wheel aforesaid. The second column gives the number of cubic feet of water per second, which constitutes a mill power for that head, when there is no back water, that is to say, when the general level of the surface of the open portion of the empty basin near the cross dam is not above the bottom of the said wheel. The third column gives the number of cubic feet per second required for a mill power, when the back water, or general level of the said portion of the basin, is one tenth (01) of a foot above the bottom of the wheel. The fourth column gives the quantity of water per second required for a mill power, with two tenths of a foot of back water. The fifth column gives the quantity per second, when there are three tenths of a foot of back water.
    “ And in general, in a line with the figures in the first column, which gives the head or height of the full basin, and under those figures in the upper line which designate the height of the back water, or general height of the surface of the said portion of the empty basin, will be found the figures expressing the number of cubic feet of water per second, which constitutes a mill power in the said state of the two basins, that is to say, with the head and the back water so designated.”
    [Here followed a table of figures, expressing, in one column, the cubic quantities of water required to be drawn, in each second of time, upon the standard wheel of the City Mills, in order to grind rye into merchantable meal, at the rate of eight bushels in an hour, with a given pair of stones, under all the varieties of head and fall occasioned by varying heights of water in the upper basin, or mill pond, through a series of levels; describing, by steps of one tenth of a foot, from 10J feet down to 5 feet, above the bottom of the wheel, so long as the general level of the water in the lower, or receiving basin, remains below the bottom of the wheel, and causes no obstruction by back water; and also expressing, in other columns, the increased cubic quantities required to be drawn, for the same work, under all the foregoing varieties of the upper basin, as modified by varying depths of water in the lower basin, through a series of levels, ascending, by similar steps, from one tenth of a foot to two feet above the bottom of the wheel, so as to cause a diminished fall, with more or less of obstruction from back water.]
    “As to the manner in which the water, which the said Gray and those claiming under him, are entitled to draw and use as aforesaid, shall be delivered, the said commissioners are of opinion, that the said Gray has a legal right to, and they award and order that he may, draw the same through such apertures as he may place in his flumes, and at such heights as he may find convenient for drawing the quantity or quantities to which he is entitled as aforesaid, under the different varieties of head and of back water ; and he may distribute the same on his several wheels, in such proportions as he shall see fit, or find convenient for his work.
    “ And as to the manner in which said water shall be measured ; inasmuch as there is no convenient method known to the said commissioners, of measuring, before the use of the same, the said eight mill powers or quantity of water, under all the varying circumstances of head and of back water, and delivering the same at the heights at which the said Gray, and those claiming under him, have a right to have the same delivered, (that is to say, the same height at which it may stand at the said City Mills,) the said commissioners award and direct, that the following shall be the method for measuring the said quantity or quantities of water, viz. The main race running through the premises leased to said Gray, and to the distance of one hundred feet northerly therefrom, shall be enlarged to the width of sixt) feet, and shall be of the same depth with the present race.
    “ This race, so enlarged, shall be divided by a course of sheet piling, rising above high water mark, commencing on the westerly side of the main race, sixty feet above the point where the said Gray’s upper race communicates with the main race, and running in a northeasterly direction, so as to make, with the general direction of the race, an angle of about thirty degrees, to the middle of the main race so enlarged ; then down the main race, dividing it longitudinally into two portions, each thirty feet in width, to a point at least thirty feet northerly of the north line of the premises leased to the said Gray; the said sheet piling to be so confined as not to be liable to be displaced or put out of line by the action of the water or ice. This will leave a race of thirty feet in width, and about four feet in depth, below the bottom of the wheels of the iron works, which shall be for the exclusive use of these works.
    
      “ Over this race, near the north line of the said leased premises, but beyond the same, shall be erected a wheel house, to contain a paddle wheel or float wheel, for the purpose of measuring the water discharged from the said iron works or mills. This wheel shall be constructed upon the same principles with that adopted by Col. William Boardman for measuring the watei at the said City Mills and at the said iron works, and used at the said City Mills by the said commissioners in their experiments. The said measuring wheel shall be twenty four feet in length and fourteen feet in diameter, with eight floats six feet in width, extending three and one half feet, below the bottom of the standard wheel at the City Mills, and running close in the race, (reduced in width in this part so as just to receive the wheel,) over a cylindrical apron way fitted to the circumference of the wheel, and embracing forty six degrees of this circumference, or about twenty three degrees each way from the bottom of the wheel. The supports of this wheel shall be attached to the mud sills which support the cylindrical apron way, so that the rests of the measuring wheel may maintain to this apron way their relative position. To one of the journals of this wheel an apparatus of clock-work shall be attached, with a graduated dial-plate, and an index to mark the revolutions of the wheel. Near the end of the wheel a water gauge shall be inserted, which shall give the precise depth of the water above the bottom of the cylindrical apron board ; and a table shall be prepared, which shall give, for every depth of the water, the quantity which passes in every revolution of the wheel. This wheel shall be so constructed as to admit of its being lifted from the race when it is not used. There shall be a gauge in the upper basin to show the height of the watei there, and another in the lower basin to show the height of the back water.
    “ By the fixtures and apparatus, constructed and made according to the foregoing directions, the number of mill powers, or quantity of water which shall at any time be used by said Gray, or those claiming under him, at the said iron works or mills, shall be measured and determined.
    
      “ And the said commissioners do further award and direct, that the said fixtures and apparatus for measuring the water as aforesaid shall be constructed and made under the direction and superintendence of some person to be agreed on by the said parties, provided they shall agree upon some person within ten days from the date of this award; and if they shall not so agree, then that they shall be constructed and made by the said Boston Water Power Company within sixty days from the date of this award, and that they shall be maintained and kept in good order and repair by the said company, their successors or assigns, during the continuance of the term of the said lease; and the expense of making and maintaining the same shall be paid as follows, viz. two third parts thereof by the said Boston Water Power Company, their successors and assigns, and one third part thereof by the said Gray and those claiming under him.
    “And the said commissioners further award and direct, that the said Boston Water Power Company, their successors and assigns, shall have the care and custody of the said fixtures and apparatus; but either of the said parties may use the same for the purposes for which it is directed to be made, whenever they may deem it expedient.
    “ Second. As to the questions and matters submitted to the said commissioners by the third article in the said indenture, they are of opinion, that the said Gray has at times had and enjoyed greater powers than were granted to him by the said lease, from the date thereof; but they cannot ascertain with precision the extent, duration and times of such excesses, for the period of about ten years from the said date; and it is not necessary, in their opinion, so to do, because they are of opinion that the lessors have not a good and legal claim for damages for such excesses ; because, from the conduct of the said parties to the said indenture of submission, in the opinion of the said commissioners, there was a mutual acquiescence, by the said parties, in the manner in which the powers to which said Gray was entitled under the said lease were had, used and enjoyed by him during that time. From their examination, and from experiments made by them at said iron works, and their obser-va.tion of the work done, and the machinery in motion at the time, and from the evidence produced at the several hearings, the said commissioners are of opinion, that from the beginning of the year Í832 the said Gray has had and enjoyed fifteen or more mill powers for about three fourths of the time; and that, for the other fourth part of said time, he has had and enjoyed a quantity of water, varying from between ten and eleven up to fifteen mill powers, with the exception of the deficiency occasioned by a breach in the main dam, which took place on the 13th day of October 1833, and of the occasional deficiencies from unusually low tides, hereinafter mentioned. And the said commissioners are of opinion, that said Gray has not heretofore had and enjoyed at all times the full use of the powers to which he was entitled; that there was a deficiency in consequence of the said breach in the main dam ; and that there have been a few tides in each year, in their opinion less than one in a month, in which the said Gray may not have had and enjoyed, during the whole tide, the eight mill powers to which he was entitled, after the said lease to said Boott and Lyman.
    “ As to the legal claims of the said parties for damages for the said excesses and deficiencies, the said commissioners are of opinion, that the said Boston Water Power Company has a legal claim against said Gray for the rent of two and a half additional mill powers employed by him, since the first day of January 1832, with the exception of the time for which the said Gray has a claim to exemption from rent as hereinafter mentioned, but that the said Gray ought not to pay interest thereon. And they are of opinion that said Gray ought not to recover damages for the said occasional deficiencies, because, in their opinion, it must have been understood by the parties to the said lease, that the said water power would necessarily be liable to occasional short deficiencies, from the manner in which it was created; because the said Gray has enjoyed an excess over two and a half additional powers as before stated; and because of his acquiescence as aforesaid.
    “ The said commissioners are of opinion, that the breach in the mill dam, which took place on the 13th day of October 1833, was caused by inevitable accident; that in consequence of said breach, the powers to which said Gray was entitled became inconstant, and were greatly deficient for the period of five months and four days ; and that, by the provisions of said lease, said Gray was legally entitled to an exemption from rent during the said time of said deficiency, and for twice the duration of the same, immediately after the remedy thereof; and «3 the said Gray was called upon to pay, and did pay, rent under said lease, for the said time, they are of opinion that he has a legal claim against the said Boston Water Power Company for the same, together with interest from the times of his payment of the said rent.
    “ Third. The said commissioners are of opinion, and do award, that the said Horace Gray, and those claiming under him, (not including the said Boott and Lyman,) are legally entitled to have, use and enjoy eight of the ten mill powers leased and demised by the said Boston and Roxbury Mill Corporation to the said Gray, as aforesaid, in the manner the same are de fined, described and set forth in the said lease and in this award, during the remainder of the term of the said lease, and to use and enjoy the same at all times, by night as well as’ by day.
    “ Fourth. The said commissioners are of opinion, and do award, that the said Gray, and those claiming under him as aforesaid, are entitled to the use and enjoyment of the said mill powers, so long as the said basins will furnish the same; and as between the said Boston Water Power Company and the said Gray and those claiming under him, that they have a legal right to be first fully served to the extent of the said eight mill powers defined, described and set forth as aforesaid, and that the said Boston Water Power Company are legally bound to discontinue, and shall discontinue, the use of their own mills, in part or altogether, whenever and so long as it shall be necessary to the full use and enjoyment of the mill powers belonging to the said Gray and those claiming under him as aforesaid.
    
      “Fifth. The said commissioners are of opinion, that the said parties of the first part in said indenture of submission are responsible to the said Gray, and those claiming under him, foi any damages they may sustain from the proper and legal use of the mill powers leased and demised to other persons, after the said lease to the said Gray ; but that they are not liable to damages for any injury the said Gray, and those claiming under him, may sustain, by reason of the said subsequent lessees using an excess of water beyond what they are legally entitled to draw and use by their respective leases.
    “ Sixth. The said commissioners are of opinion, that the said Gray did not acquire a legal right, under and by virtue of the said lease, that the lessors should keep and preserve the basins and dams, by which said mill powers were created, in precisely the same state in which they were at the date of the said lease, during the continuance of the term of the said lease. The said Gray, and those claiming under him, have not a legal right of flowage to any particular line or extent in the receiving basin. The said lease does not contain a grant or warranty of such a right, either express or by implication, and it did not pass as incident or appurtenant to the subject of the grant. But the said commissioners are of opinion that the said Gray, and those claiming under him, have a legal right to so much flowage, and to such an extent, in the said receiving basin, at all times, as shall be necessary to the full enjoyment of the power granted to the said Gray in the said lease. And the said commissioners are of opinion, that the parties of the first part in said indenture are legally bound not to alter, or in any way affect or change, the said basins, or either of them, in such manner or degree, that the power granted in said lease may thereby be defeated or become deficient. And they award and order, that the said parties shall not alter, change, or do any act or thing whatever, nor consent to the doing of any, by means of which the said Gray, and those claiming under him, may be prevented from the full enjoyment of the powers granted to him by the said lease. And the said commissioners are of opinion, that the said Boston Water Power Company have a legal right to enter upon the receiving basin, and to remove obstructions to their water power arising from accretions, and that they are legally bound to do so, whenever it shall be necessary to the full enjoyment of the privilege or mill powers granted to said Gray by the said lease.
    “ Seventh. The said commissioners are of opinion, that said Gray has not a legal claim to damages against the said Boston and Roxbury Mill Corporation, on account of said corporation having agreed with the owners of the upland adjoining said receiving basin, on a boundary line between the said basin and the said upland.
    “ Eighth. The said commissioners are of opinion, that said Gray has not a legal claim to damages against said corporation on account of their having leased other mill powers, subsequently to the said lease to said Gray, because, at the times they were made, respectively, the said lessors owned and were possessed of sufficient water power to enable them to make said subsequent leases, without interfering with or diminishing the powers previously granted to said Gray.
    “ And the said commissioners further award and order, that whatsoever is herein directed to be done by either of the said parties, shall be specifically performed by the said party.
    “ The costs and expenses which have arisen under the said indenture of submission are as follows: viz.
    “ Leverett Saltonstall, his services and expenses,.$ 1,000
    Loammi Baldwin, charged by his executors,.1,800
    James Hayward,.3,000
    Assistant engineers, surveyors, &c. employed by the commissioners, 2,586 78
    Millers and assistants in grinding,. 759 05
    Peasley’s bill, and sundry expenses,.87 12
    Carriage hire,.199 13
    Boston Water Power Company, for use of their mill, &c.1,438
    Same, for cash paid for lumber, labor, &c. 665 52
    H. Gray’s bill, for labor, &c. 64 69
    Boston and Roxbury Mill Corporation, tolls,. 27 89
    , In the whole, the sum of $ 11,628 18
    “Of whicn the sum of $2800 has been paid by the said parties.
    “ And the said commissioners award and order, that the said costs and expenses shall be divided equally between the said parties, one half to each, and that the ordinary expenses of reference, for witnesses, &c., which are not taxed, shall be paid according to the provisions of the said indenture, and adjusted by the counsel for the parties.
    “ All which is in full of all matters submitted to the commissioners by the said indenture of submission.
    
      “ Leverett Saltonstall.
    “James Hayward.”
    The plaintiffs counted upon the aforesaid indenture of submission and the award aforesaid, and averred, in their declaration, that they had paid, on the 27th of November 1838, the sum of $4200-11, for the cost of the measuring wheel, apparatus and fixtures, which said commissioners, by their award, had directed to be made, and which had been made accordingly ; and that the defendant ought to have paid them, pursuant to said award, one third of said sum, viz. $ 1400-04; and that the rent of 2| powers, since January 1st 1832, deducting five months and four days for breach in the dam, amounted to $4191-24; and that after a deduction therefrom of the rents and interest returnable to the defendant, according to said award, there remained due to the plaintiffs a balance of $ 159-89, for which they had a legal claim, at the time of the publication of the award. The refusal of the defendant to pay these two sums, or either of them, after demand of payment thereof, was set forth as the breach of covenant for which the plaintiffs demanded damages in this action.
    The general issue was pleaded and joined, and the defendant filed a specification of defence. The trial was before Shaw, C. J., who reported the case in substance as follows:
    It was conceded that the commissioners made no actual experiments in grinding rye at the City Mills, at any time when the water of the full basin stood at a less height than 6 feet and 1-10th above the bottom of the wheel; nor at any time when it stood at a greater height than 9 feet and 3-10ths above the same; nor at any time when the water in the receiving basin stood at a greater height than 1 foot and 5-10ths above the same; the said range of heights in the full basin, between 6 feet and 9 feet 4-10ths, occupying of the whole period of time within which the commissioners were making their experiments; and the said heights of back water in the receiving basin having been raised by artificial means, for the purpose of the experiments. It was also conceded that the bottom of the lowest gate, through which water was drawn by the commissioners, in their experiments, stands at the height of 5 feet and 6 inches above the bottom of the wheel, the same being the third gate at the City Mills, and a fourth gate, opening below the said third gate, was not used by the commissioners in their experiments, by the defendant’s request and agreement of parties, because said fourth gate did not exist at the time the lease to said Gray was made.
    Samuel Nicholson, a witness for the plaintiffs, testified that the measuring apparatus had been constructed conformably tc the award, and that the cost of it corresponded to the sum stated in the declaration, and had been paid for by the plaintiffs, and that he presented to the defendant a 'bill of one third of the expense, and also for the balance due from him, under the award, for the use of water, and demanded payment February 19th 1839, which was refused.
    The plaintiffs then rested their case.
    The defendant relied upon two classes of objections to the award. The first was, that the arbitrators had exceeded their powers ; and the second, that they committed gross errors and mistakes in their award, which vitiated all its results.
    Under the first class of objections, the defendant contended that the arbitrators had exceeded their powers; 1st, in deciding that said Gray was bound at any time to draw the water through gates lower than those constructed, and set up, and used at the City Mills, at the date of the original lease to said Gray.
    The lowest gate at the City Mills, at the date of the lease, was 5 feet and 10 inches above the bottom of the wheel, and the defendant contended that no authority was given to the commissioners to decide that he was bound to draw the water at a lower height, and that in so deciding they had exceeded their power.
    
      The defendant further contended that the arbitrators exceeded their powers, 2d, In assessing a portion of the expense of the measuring apparatus upon said Gray: 3d, In ascertaining and determining the number of mill powers which the said basins will afford at any and every tide, at the cost and expense of the defendant, inasmuch as the personal charges of said commissioners were to be by the submission, and were by said award, equally divided between the parties: 4th, In directing that the plaintiffs should remove accretions of the basins, when they were not owners of the same j that this was a consideration of the other parts of the award, and therefore affects and vitiates the whole award: 5th, In directing the measurement of the water at the time and place, and in the mode, prescribed in their pretended award: 6th, In deciding that it must have been understood by the parties to the said lease, that the said power would necessarily be liable to occasional short deficiencies, from the manner in which it was created.
    Under the second class of objections, the defendant contended that the commissioners had made gross errors and mistakes which vitiate their award: 1st, Because the table in said award was constructed from a rule derived from a gross misconception of the action of water upon a wheel, and there are gross errors and mistakes in the same, inasmuch as the commissioners com mitted a material error in neglecting to make a proper and correct allowance for the loss of head in getting the water upon the wheel, and in its leaving the wheel by spilling out: 2d, Because they did notallow the same power to overcome the same resistance of back water: 3d, Because the increase of power allowed for an increase of back water is less than the increase of resistance: 4th, Because the award is not throughout, as it professes to be, the result of experiments, or correctly deduced from experiments: 5th, Because, in making their experiments in grinding, the mill stones used were kept constantly sharp, and were frequently picked, and the meal was cut and not floured, as was usual and customary at the date of the lease to said Gray, as it should have been by said commissioners : 6th, Because they took 54 pounds to be a bushel, instead of 56 pounds, as provided by St. 1817, c. 130: 7th, Because, while they profess to decide that said Gray has no claim for damages on account of the contract with abutters, they decide that thereby said Gray has not had his full power, and the awaid is inconsistent with itself: 8th, Because, if they nad a right to award that the Boston Water Power Company should remove accretions, they were bound to have imposed the same duty on the Boston and Roxbury Mill Corporation : 9th, Because they did not direct how the water should be measured and delivered; and because the mode which they have prescribed for the measure of the water, after the same is delivered, is essentially defective: 10th, Because, if this award be established and set up by the court, the defendant may be compelled, at the pleasure of the plaintiffs, to receive and pay for, under a given head and fall, fixed in said table, as and for all the powers to which he is entitled, a quantity of water which is given by the tables as constituting a mill power; which quantity is not ascertained by, and is not the result of, experiments, and is of no practical value: 11th, Because the plaintiffs’ remedy for any excess of power used by said Gray was by measuring and delivering the true quantity; and the commissioners erred in awarding any other than nominal damages for any such excess: 12th, Because they give a quantity of water to constitute a mill power, greater than the buckets can hold: 13th, Because the table professes to give a constant power, whereas it appears by the award that the power is inconstant and insufficient, and no provision is made for such inconstancy: 14th, The defendant’s counsel also contended, that if the commissioners did not exceed their powers in directing the measurement of the water as they did, and in deciding that it must have been understood by the parties to the lease that the power would necessarily be liable to occasional short deficiencies, from the manner in which it was created, yet they committed gross errors and palpable mistakes in these respects: 15th, The defendant’s counsel also contended, that the referees had made a mistake in the application of their own principles; that they had made experiments, but had not constructed the table upon those experiments ; and that when referees make a mistake in carrying out their own principles, it is a good ground for setting aside an award : That the table leads to the necessary inference that actual experiments were made at the lower gate of five feet; that power is set down as an actual experiment, and that the table does not give what the referees intended.
    The defendant’s counsel then offered evidence to support the grounds of objection above stated; expressly disclaiming all imputation of fraud, corruption, or intention of misbehavior of the commissioners.
    The plaintiffs’ counsel objected to the admission of any evidence to prove error in the award, on the ground that no error was admitted by the referees, and that it was not competent for the defendant to show, by extrinsic evidence, any error which they did not admit, and also because of the insufficiency of the specification of defence to let in evidence of the errors proposed to be shown; and they contended that all the objections taken by the defendant, excepting such as were founded on a supposed departure of the award from the submission, were objections which could not be maintained, unless by the aid of extrinsic evidence, and that the award did not vary from the submission.
    The fore-going questions having been fully argued, the judge ruled upon them as follows: “ That awards might be set aside for fraud, accident or mistake; and, it being conceded by the defendant that there had been no misconduct of the arbitrators, the great question was, how far the defendant could be allowed to go into evidence to show error in this award: That, in general, referees were the judges, constituted by the parties, of all questions of law and fact submitted to them, and of the rights depending on those questions, and that their judgment was conclusive: That there were some exceptions as to questions of law; as if the referees decide on condition that the law is as they assume ; or where they manifestly intend to decide according to law, but mistake it: That the burden of proof was on the defendant, who impeached the award: That in judging of it, the submission was always undoubtedly to be taken into consideration; and that, in the present case, the lease under which the questions arose might also be taken into consideration, as being by reference incorporated into tne submission ; but that the provision in the present indenture of submission, supposed to require that the referees should decide according to the legal rights of the parties, was not to be construed as a limitation of their authority, so as necessarily to open all questions of law to a revision of the court, but rather as an agreement of the parties that the referees should apply the rules of law according to their own judgment: That the causes generally open for setting aside awards, were, 1st, Exceeding the submission : 2d, Failing to decide the matter submitted ; both of which might be classed together as a failure of the private tribunal to accomplish the purpose of its creation: 3d, Fraud in the party in whose favor the award is rendered: 4th, Corruption, partiality or misbehavior of the arbitrators: 5th, Accident and mistake, leading to gross errors; and in respect to these, that they need not appear on the face of the award, but might be shown aliunde: That the question then would be, what is such accident or mistake as opens this species of inquiry. It must be an inadvertence, by which some error was adopted, or some fact, through accident, erroneously overlooked; and not a matter either of fact or law, brought under the consideration of the referees, and acted upon or judged of by them, although it may have been judged erroneously. Their judgment on those subjects on which their minds were exercised, is conclusive. The effect of their award is something like that of a verdict, but more like that of a verdict followed by a judgment ; the powers of both court and jury being combined in arbitrators. That it was not open to the defendant, therefore, to show that the referees did not give due weight to particu.ar facts, or that they drew wrong conclusions from them, as to the quantities of water constituting a mill power, or to show that other persons would have thought otherwise, and would have drawn different conclusions from the same premises; nor would any evidence be admissible, as tending to show that they adopted a false theory concerning water power; for if it were proved that they had made a mistake in the principles of water power which they adopted, this would not be such a mistake as would set aside their award: But that it was competent for the defendant to show that the arbitrators by mistake assumed a particular fact to be true, which is not true, or that they wholly overlooked something which they ought to have considered. This was i lustrated by supposing that the subject for their inquiry was the ascertaining of the contents of a certain area. It might be admissible to show that a measuring chain, inadvertently used by them, was false and erroneous. But if they should think it necessary or expedient to invent some more complicated instrument of measure, founded upon geometrical principles, and having reference to astronomical laws, and, having determined by such instrument, should adjudge the contents of the area to be according to the result so given, it would not be competent to show, by the testimony of other geometricians and astronomers, that they had erved in the principles by which they constructed their instrument of measure, and so arrived at wrong results. That the rule was, that the defendant might show that the referees inadvertently omitted or overlooked something materially affecting the award, and producing error, but not that they erroneously judged, without inadvertence, since this would be allowing a general right of appeal from awards: That questions of law, respecting the conformity of the award to the submission, were open upon the comparison and construction of those two papers and of the lease referred to. In respect to them, it was ruled that the referees did not appear to have exceeded their authority in deciding upon quantities of water as constituting a mill power, under certain circumstances, which the defendant might be obliged to draw at his iron works below the height at which they could be drawn at the City Mills; as the lease rather describes the standard and test of a mill power, in regard to the varying quantities, which, if drawn at the City Mills, would constitute a mill power, than the manner or height at which those quantities are to be used at any mills which the defendant should erect: That the referees did not appear to have exceeded their authority in causing the measuring apparatus to be erected, nor in assessing upon the defendant a portion of the expense of the apparatus; since the submission superseded the provisions of the lease, in respect to a gauge, and the parties had, in effect, thereby admitted that the mode of measurement contemplated by the lease was impracticable, and had required of the referees to contrive and direct another method and apparatus for the use of the parties, and to be paid for by them : That having executed this authority, the objections taken to the sufficiency, convenience or costliness of the apparatus, would not be open to evidence : That they had not exceeded their authority in having ascertained the whole power of the basins, at the joint expense of the parties, since this was one means of ascertaining the rights of the parties, in all states of the basins, which they were required to do: Nor had they exceeded their authority in determining that, under certain circumstances, the plaintiffs should be bound to remove accretions in the receiving basin ; nor in any other respects pointed out: That, upon the whole, the only question fairly open for inquiry before the jury was, whether any such accident or mistake, through inadvertence, as can be shown according to the foregoing ruling, had in fact been committed; all the other questions, depending on the true construction of the lease, submission and award, being reserved for the consideration of the whole court.”
    The defendant then offered to prove, 1st, That the referees inadvertently omitted to make the proper allowance for loss of power in getting the water upon the wheel: 2d, That they omitted to make a proper allowance for the resistance of back water: 3d, That the table of quantities of water constituting ifiill powers in the different states of the basins, which formed a part of the award, if carried out proportionally for lower neights of water than the table itself contained, would lead to results which the referees inadvertently overlooked.
    Upon inquiry as to the mode in which he proposed to prove these points, it appeared that it was proposed to do so by the testimony of scientific witnesses, some of whom, it was said, had formerly made experiments at the plaintiffs’ mills, as to the rules or laws regulating water power, and the comparison of tables of powers in the award with the results of these rule urd with the knowledge or theory, as the case may be, of the said witnesses respecting such rules; and also offered to show, by actual experiment, on a certain wheel or apparatus erected in the court room, that the arbitrators had committed many errors in this respect. But it was ruled that this was not competent, being matter of judgment passed upon by the referees, and that the defendant was bound to show by the referees themselves, or any statements made by them, or other competent evidence of like character, that they overlooked something, which, though not apparent on the face of the award, might constitute an inadvertent mistake.
    The defendant’s counsel then moved to examine James Hayward, one of the commissioners, as to the mode in which their experiments were conducted. It was ruled that this was not admissible, and that the inquiry must be confined to the point, whether the referees omitted to take into consideration the subjects of proper allowance for loss of head or resistance of back water, or other matters supposed to be sources of error.
    The defendant’s counsel then proposed to inquire of Mr. Hayward what formula or rule the table of powers was constructed by. But this was ruled to be inadmissible.
    To these rulings the defendant’s counsel excepted at the trial. A verdict, pro forma, was taken for the plaintiffs, for the sum of $2000. And all the questions of law stated to the judge, and the exceptions to the rulings above stated, were reserved for the full court. If any of the rulings were erroneous and material, or if the court should be of opinion that a trial should be had by the jury on any point, v/ith the exception of the amount of damages, a new trial is to be granted ; but if the court shall be of opinion that the rulings were correct, and that none of the defendant’s objections to the award can be sustained, then judgment is to be rendered for the plaintiffs for such sum as the counsel shall agree ; or if they do not agree, for such sum as shall be fixed by an assessor to be appointed by the court.
    And it was agreed, that certain lines, marked on the table contained in said award, include all that part of the table which was the subject of actual experiment; and that during parts of the whole period of time within which the experiments were in progress, the water of the full basin did not rise above or fall below the heights comprised within those lines; nor the height of back water in the receiving basin equal, except by artificial means, the heights therein comprised.
    This case was argued at great length, on all the questions raised in the foregoing report. The very full opinion of the court renders it unnecessary to prefix thereto any thing more than a statement of the grounds taken by counsel as to the law respecting awards.
    
      Greenleaf & W. Gray, for the defendant.
    Where arbitrators exercise a power not conferred, or omit to exercise a power that is conferred, their award will be set aside. So where they commit gross errors or mistakes, in law or fact, whether extrinsic or apparent on the award. Watson on Arb. 105, 115, 161, 168. And the error or mistake need not be shown by the arbitrators themselves, but may be proved by other witnesses1 or proof. Greenl. on Ev. § 249.
    Mistakes made by arbitrators on their own principles are a cause for setting aside their award. Allen v. Ranney, 1 Connect. 569. So other mistakes of fact or law, apparent on the face of the award, if material, are ground of relief in equity. 2 Story on Eq. <§> 1453. Corneforth v. Geer, 2 Vern. 705. Eden on Injunctions, 7. And the rule is the same at law, in this Commonwealth. Bean v. Farnam, 6 Pick. 274. Mistakes also, which are not apparent on the award itself, are cause for setting the award aside, and may be proved by other evidence than the testimony of the arbitrators. Jones v. Boston Mill Corporation, 6 Pick. 155. Hall & Hind’s case, 2 Man. & Granger, 847. Hurst v. Hurst, 1 Wash. C. C. 56 N. Yarmouth v. Cumberland, 6 Greenl. 26. 1 U. S. Digest, Arbitrament and Award, 450. Alder v. Savill, 5 Taunt. 454. Indeed, arbitrators are not to be inquired of respecting their award. 3 Atk. 644. Greenl. on Ev. <§> 249. Johnson v. Durant, 4 Car. & P. 327, & note.
    
    A contract of submission to arbitration is to be construed according to the intention of the parties; and a presumption is not to be made, that parties intend to put themselves beyond the supervising power of the courts. By a general submission, matters of law are not referred to the final decision of the arbitrator, and his award may be set aside by the court, if he decide contrary to plain law. Hide v. Cooth, 2 Vern. 109. Kent v. Elstob, 3 East, 18. Morgan v. Mather, 2 Ves. jr 18. Nichols v. Chalie, 14 Yes. 265, 270. Young v. Walter, 9 Ves 367. Blennerhassett v. Hay, 2 Ball & Beat. 120. Greenough v. Rolfe, 4 N. Hamp. 357. 1 Taunt. 52, note. Ames v. Mil-ward, 8 Taunt. 637. Kelly v. Johnson, 3 Wash. C. C. 45. Gross v. Zorger, 3 Yeates, 521. Ross v. Overton, 3 Call, 309, and 2 Hen. & Munf. 408. Heuitt v. The State, 6 Har. & J. 95. Lower Hublin School v. Paul, 1 Binn. 59. Head v Muir, 3 Rand. 122. Alwyn v. Perkins, 3 Desaus. 297.
    The rule is doubtless different, where the parties agree to submit questions of law to the arbitrators, and perhaps also, where professional men (“legal arbitrators”) only are selected as arbitrators. Ching v. Ching, 6 Ves. 282. Smith v. Thorn-dike, 8 Greenl. 119. Bigelow v. Newell, 10 Pick. 348. Steff v. Andrews, 2 Mad. R. 6. Chace v. Westmore, 13 East, 357 Campbell v. Twemlow, 1 Price, 81. Price v. Hollis, 1 M. & S. 105.
    It is only the general merits of an award that will not be examined, except on a charge of fraud or corruption in the arbitrators. Goodman v. Sayers, 2 Jac. & Walk. 259. Wood v. Griffith, 1 Swanst 43 Large v. Passmore, 5 S. & R. 51. Brown v. Bellows, 4 Pick. 192. Underhill v. Van Cortlandt, 2 Johns. Ch. 361. The marginal abstract of this last case does not correctly state the doctrine as expressed by Chancellor Kent in his opinion.
    
      C. G. Loring & Gardiner, for the plaintiffs.
    Where a submission is entered into by agreement of parties, extrinsic evidence is not admissible to impeach an award, except to show a departure from the submission, fraud or corruption in the arbitrators, or a mistake, admitted by them, of a fact which they deem material. In the case at bar, therefore, as no error appears on the face of the award, none of the evidence, which was offered and rejected at the trial, was admissible; and none that was received shows a departure from the submission.
    By the English law, such awards as that in question are like judgments of court. They are not examinable by the courts, nor impeachable by plea, for any cause that would not apply to a judgment of a court of peculiar jurisdiction. Watson on Aib. 153. 1 Stark. Ev. 211, 252. Newland v. Douglass, 2 Johns. 62. Barlow v. Todd, 3 Johns. 367, and 2 Johns. Ch. 551. Cranston v. Kenny, 9 Johns. 212. As this court has no peculiar equity jurisdiction over awards, certain objections to them are received here, which can be heard in England only in equity. But this court goes no farther than equity courts. 6 Pick. 273, 274. What cases of latent mistake of fact can be shown in equity ? Only such as are admitted by the arbitrator, and regarded by him as material to his judgment. Knox v. Symmonds, 1 Ves. jr. 369. Morgan v. Mather, 2 Yes. jr. 15. Dick v. Milligan, 2 Ves. jr. 23, and 4 Bro. C. C. 117. Goodman v. Sayers, 2 Jac. & Walk. 259. Taylor v. Nicolson, 1 Hen. & Munf. 67. 2 Johns. Ch. ubi sup. 2 Story on Eq. <§, 1456. And as to mistakes of law, courts of equity will not interfere, unless the arbitrator refers the question to the court, or it is clear that he has mistaken the law, when he meant to abide by it. Kleine v. Catara, 2 Gallis. 70. Young v. Walter, 9 Ves. 364. Ching-v. Ching, 6 Ves. 282. Watson on Arb. 161 —169. 2 Story on Eq. § 1455. Johns v. Stevens, 3 Verm. 314. Nor will such court receive extrinsic evidence to show a mistake of law, except only to prove the fact, that the arbitrator did not intend to decide against law. Watson on Arb. 163. Richardson v. Nourse, 3 Barn. & Aid. 240. If the court of chancery in England has any further power over awards, it is upon its general equity power to reform contracts, so that they shall conform to the intent of the parties; a power not conferred on this court. Leach v. Leach, 18 Pick. 68.
    The following authorities further show the conclusiveness of awards, both as to law and fact, under the rules above stated, and also that there is no distinction in this respect between “legal arbitrators” and others. Pleasants v. Ross, 1 Wash. 156. Campbell v. Western, 3 Paige, 124. Blackledge v. Simpson, 2 Hayw. 30. Hardy v. Ringrose, 1 Har. & Well. 185. Wilson v. King, 2 Crompt. & Mees. 689. Jupp v. Grayson and Barrett v. Wilson, 1 Crompt. Mees. & Rose. 523, 586. Perriman v. Steggall, 9 Bing. 679. Armstrong v. Marshall, 4 Dowl. P. C. 593. Wade v. Malpas, 2 Bowl. P. C. 638. 4 Harrison’s Digest, (Amer. ed.) 2296. TJnderhiTl v Van Cortlandt, 2 Johns. Ch. 339. Watson on Arb. 163 — 165.
    The case at bar falls within one of the rules which the defendant’s counsel admit, viz. that where parties agree to submit questions of law to the decision of arbitrators, their decision is final. These parties have most clearly made such agreement.
    
      
       The lease here referred to was as follows:
      “ This indenture, made this 6th day of June 1822, by and between the Boston and Roxbury Mill Corporation, of the one part, and Horace Gray of the city of Boston, Commonwealth of Massachusetts, merchant, of the other part, witnesseth, that the said corporation, in consideration of the covenants and conditions hereinafter made, on the part of the said Gray, his executors, administrators, and assigns, doth hereby grant, lease, and demise unto said Gray, a certain piece of land situate on Gravelly Point, so called, in Roxbury, in the county of Norfolk, and said Commonwealth, bounded as follows, to wit: Beginning at the cross dam road, where the eastern wing wall, so called, meets the same, thence running along the face of said wall, and at a right angle with said road, more than 300 feet to the eastern boundary of the land conveyed from Israel Thorndike, Ebenezer Francis, and David Sears, by a certain deed of indenture, made by and between said corporation, of the one part, and said Israel, Ebenezer, and David, of the other, dated on the 8th day of March 1820, and recorded in the registry of deeds, of the county of Norfolk, in book 62, folio 112, thence running southerly along the said eastern boundary line, 300 feet, thence at a right angle with said boundary line to and across the said cross dam road, and across the beach and canal on the western side thereof, to a row of stakes on the western bank of said canal, thence northerly by said row of stakes along the western bank of said canal, to a point in the line with the western wing wall, so called, thence along the face of the said western wing wall, to the said cross dam road, thence across said road to the bounds first mentioned; subject, however, to all the conditions and restrictions contained in the indenture aforesaid, by which the same was conveyed to the said corporation. Reserving also to the said corporation, and all claiming under it, the right of passing in and along the said canal, but not of stopping therein, or in any manner obstructing the same.
      41 And the said corporation doth also grant, lease, and demise unto the said Gray, the following described mill privilege, to wit: The privilege cf drawing through convenient flumes of stone, to be made by said Gray in and through the said road or dam, wherever he may choose, within the limits above set forth, a quantity or quantities of water, the power of which shall at all times be equal to ten mill powers. And it is expressly understood and agreed between the parties, that a quantity of water equal to that which is now required, under any given head and fall, to grind with one of the water wheels, and one pair of the mill stones contained in the grist-mill belonging to the corporation, as the same are now constructed and set up, eight bushels of rye, into good merchantable meal, in one hour, shall be deemed equivalent, under the same head and fall, to one mill power.
      “ And the said corporation doth further grant unto said Gray a right, in common with the corporation and all persons claiming under it, of landing at the general landing place, on the north side of the main dam built by said corporation, all goods or materials which said Gray, or any person claiming by or under him, may have occasion for upon the premises; which landing place begins on the north side of said main dam, 180 feet east of the filling sluices at the end of the wharf now built, and extends eastward 150 feet: And also a right of way and of carriage for him, and for all persons claiming under him, to and fro between said landing place and the land herein above demised, free of toll across the main dam, but not lengthwise thereon.
      “ To have and to hold the premises hereby granted, with all the privileges and appurtenances thereto belonging, to him the said Gray, his executors, administrators and assigns, for and during the full term of one hundred years, from the 10th daj of April now last past, he and they paying and yielding therefor, until the 10th lay of January 1824, nothing : and on the last named day, and on every 10th day of April, July, October and January, afterwards, during the continuance of this lease, the sum of $ 787*50.
      “ And the said corporation, for itself, its successors and assigns, doth hereby covenant to and with the said Gray, his executors, administrators and assigns, as follows, to wit: First: That if the power hereby granted shall, at any time, be found insufficient to carry on the works which shall be erected by the said Gray, his executors, administrators and assignees, then he or they may employ any further power, not exceeding one quarter part of the power herein above granted, he and they paying rent for the same quarterly, at the rate of $315 by the year for each additional mill power, but shall not be entitled to have any land with such addition of power. Second: That neither said corporation, nor any one claiming by, from, or under it, shall, at any time within 10 years from the said 10th day of April now last past, sell, grant, or use any mill privilege or water power whatsoever for working in iron j provided however, that any person or persons occupying mills under the said corporation shall have the right to make necessary tools and machinery for his or their own use only in the said mills. And the said corporation will, in every future lease, reserve the right to enter and expel the lessee and his assigns, or to stop his flumes, by its directors or agents, if he. or any under him, shall use any mill power for working in iron, except as aforesaid, and will authorize the said Gray, his executors, administrators, and assigns, to exercise these rights, as its agent or agents, in case the exclusive privilege herein above granted to him and them should be at any time violated. Third : That the said Gray, his executors, administrators or assigns, may at any time surrender and abandon this lease, upon paying to said corporation the sum of $1575. Fourth : That the said corporation, its successors, and assigns, will at all times keep and maintain their dam and sluice-gates in good and sufficient repair, and will not do any act whatever, whereby the power hereby granted may De in any wise defeated or diminished. But it is expressly understood and asieed* that, if by inevitable accident, or by any cause beyond the control of the said corporation, its successors, or assigns, the power hereby granted shall become deficient or be destroyed, the corporation, its successors and assigns, shall not be bound or holden to pay any damage necessarily occasioned by such inevitable destruction or deficiency ; but in such case, the said Gray, his executors, administrators and assigns, shall be exempted from rent during the continuance of such deficiency, and shall be allowed, immediately after the remedy thereof, to hold the premises for a time equal to twice the duration of such deficiency, free of rent, provided the time thus allowed after such removal shall in no one instance exceed two years.
      “ And the said Gray, on his part, for himself, his executors, administrators and assigns, doth hereby stipulate, covenant and agree, with the provision and limitation hereinafter set forth, to and with the said corporation, its successors and assigns, that he and they will well and truly perform the following conditions, to wit; will pay the rent quarterly, as herein reserved, and will pay all taxes levied on the premises, and will make good and sufficient flumes of stone, for the conveyance of the water used by him or them, and a bulk head to be approved by the directors, and will dig a race-way across the eastern end of the premises, oí such width and depth as shall be requisite for the accommodation of the mills which may be erected on the land of said corporation, south of him, and will constantly maintain the same in sufficient repair, and will also put in operation a power equivalent to seven mill powers and a half, within three years. And if tie or they shall at any time neglect or fail to fulfil any one of the conditions or stipulations aforesaid, and such neglect or failure shall continue for and during he space of 30 days after notice thereof by the said corporation, then it shall be lawful for the said corporation, by its directors or agents, to enter on the premises and stop his or their flumes, or to expel him or them, and all persons occupying under him or them, and so to avoid the said term, and destroy this lease, and all his and their rights, and title and interest under it. Provided, however, and it is expressly understood and agreed, by and between the parties to this lease, that after the said Gray, his executors, administrators and assigns, shall have expended the full sum of $ 10,000, in making flumes, race-ways, buildings, and other fixtures on the premises hereby granted, and after the said Gray, his executors or administrators, shall have assigned this lease, neither he nor they shall at any time be liable to an action of covenant, or any other suit, at law or in equity, for the breach or non-performance of any of the said stipulations or conditions which may be broken after such assignment, nor in any manner holden or required to pay the rent which may accrue subsequently to such assignment, excepting the rent which shall accrue for the first 6 months thereafter : But that, after the said sum of $ 10,000 shall have been so expended, and after an assignment by him or them, and 6 months passed, as aforesaid, the sole remedies of the corporation, for the breach or non-performance of the said stipulations and conditions, or any of them, shall be such action or actions as may be legally maintained against the holds's or assignees of this lease, or the occupant of the premises, and the right of said corporation to enter and stop his or their flumes, and to expel him or them, and thereby avoid this lease, as above set forth.
      “ And it is further covenanted and agreed, by and between the parties, that the directors and agents of the corporation may at all times enter and examine the water courses on the premises, and may at all times keep a gauge therein, whereby they may, from time to time, regulate the power used according to the terms of sale, in such manner, however, as always to allow a quantity or quantities of water, the power of which shall be always equal to the mill power or privilege herein above granted, to flow freely upon the water wheels erected on the premises, and the same power shall be distributed in such proportions on the several wheels, as the said Gray, his executors, administrators or assigns, shall at any time require.
      “ And the said Gray, for himself, his executors, administrators and assigns, doth covenant, promise and agree, to and with the said corporation, its successors and assigns, that he or they will, before the 22d day of June current, begin one or more good and substantial buildings of stone, for his principal work, and also that the said stone buildings, and the water wheels appertaining thereto, shall become the property of the said corporation, without any charge or compensation, whenever this lease shall cease or determine, either by its surrender or forfeiture, or by lapse of time; and if the said lease shall not so cease and determine within 50 years from the commencement thereof, then all buildings whatsoever, erected on the premises, with the water wheels to them or any of them belonging, shall become the property of the said corporation, whenever the said lease shall, after the said 50 years, cease and determine, in either of the modes aforesaid.
      “ And the said corporation, for itself, its successors and assigns, doth covenant and agree, to and with the said Gray, his executors, administrators and assigns, that he and they, paying rent as herein reserved, and also keeping and observing all the oth?r stipulations and conditions on his and their parts tobe performed and observed, shall hold, occupy and enjoy the premises hereby granted, for and during the term aforesaid, quietly and peaceably, without any let, trouble or molestation whatsoever.
      « In testimony of which, the said corporation hath caused these presents to be signed by its president, thereunto duly authorized, and its corporate seal to be affixed thereto, and the said Gray hath thereto affixed his hand and seal, on the day and year first above written. Horace Gray. [seal.]
      Artemas Ward, Pres’t.” [seal.]
    
   Shaw, C. J.

Several questions have been argued, in the present case, upon exceptions taken by the defendant, some of them arising upon the face of the report, which were taken at the trial and overruled, and some of them being exceptions to the rejection of evidence offered at the trial, with a view to impeach and set aside the award.

It is clearly settled, that an award is prima facie binding up on the parties, and the burden of proof is upon the party who would avoid it. In general, arbitrators have full power to decide upon questions of law and fact, which directly or incidentally arise in considering and deciding the questions embraced m the submission. As incident to the decision of the questions of fact, they have power to decide all questions as to the admission and rejection of evidence, as well as the credit due to evidence, and the inferences of fact to be drawn from it. So, when not limited by the terms of the submission, they have authority to decide questions of law, necessary to the decision of the matters submitted; because they are judges, of the parties’ own clnoosing. Their decision upon matters of fact and law, thus acting within the scope of their authority, is conclusive, upon the same principle that a final judgment of a court of last resort is conclusive; which is, that the party against whom it is rendered can no longer be heard to question it. It is within the principle of res judicata; it is the final judgment for that case, and between those parties. It is amongst the rudiments of the law, that a party cannot, when a judgment is relied on to support or to bar an action, avoid the effect of it by proving, even if he could prove to perfect demonstration, that there was a mistake of the facts or of the law. But this general rule is to be taken with some exceptions and limitations, arising either from the submission, or from the award itself, or from matter distinct from either.

If the submission be of a certain controversy, expressing that it is to be decided conformably to the principles of law, then both parties proceed upon the assumption that their case is to be decided by the true rules of law, which are presumed to be known to the arbitrators, who are then only to inquire into the facts, and apply the rules of law to them, and decide accordingly. Then if it appears by the award, to a court of competent jurisdiction, that the arbitrators have decided contrary to law — of which the judgment of such a court, when the parties have not submitted to another tribunal, is the standard — the necessary conclusion is, that the arbitrators have mistaken the law, which they were presumed to understand; the decision is not within the scope of their authority, as determined by the submission, and is for that reason void. But when the parties have, expressly or by reasonable implication, submitted the questions of law, as well as the questions of fact, arising out of the matter of controversy, the decision of the arbitrators on both subjects is final. It is upon the principle of res judicata, on the ground that the matter has been adjudged by a tribunal which the parties have agreed to make final, and a tribunal of last resort for that controversy; and therefore it would be as contrary to principle, for a court of law or equity to rejudge the same question, as for an inferior court to rejudge the decision of a superior, or for one court to overrule the judgment of another, where the law has not given an appellate jurisdiction, or a revising power acting directly upon the judgment alleged to be erroneous.

It has sometimes been made a question whether the court will not set aside an award, on the ground of mistake of the law, when the arbitrator is not a professional man, and decline inquiry into such mistake, when he was understood, from his profession, to be well acquainted with the law. Some of the earlier cases may have countenanced this distinction. But the probability is, that this distinction was taken, rather by way of instance to illustrate the position, that when the parties intended to submit the questions of law as well as of fact, the award should be final, but otherwise not; which we take to be the true principle. But we think the more modern cases adopt the principle, that inasmuch as a judicial decision upon a question of right, by whatever forum it is made, must almost necessarily involve an application of certain rules of law to a particular statement of facts, and as the great purpose of a submission to arbitration usually is, to obtain a speedy determination of the controversy, a submission to arbitration embraces the power to decide questions of law, unless that presumption is rebutted by some exception or limitation in the submission.

We are not aware that there is anything contrary to the policy of the law, in permitting parties thus to substitute a domestic forum for the courts of law, for any good reason satisfactory to themselves; and having done so, there is no hardship in holding them bound by the result. Volenti non jit injuria. On the contrary, there are obvious cases, in which it is highly beneficial. There are many cases, where the parties have an election of forum; sometimes it is allowed to the plaintiff, and sometimes to the defendant. It may depend upon the amount, or the nature of the controversy, or the personal relations of one or other of the parties. As familiar instances in our own practice, one may elect to proceed in the courts of the United States, or in a state court; at law or in equity; in a higher or lower court. In either case, a judgment in one is, in general, conclusive against proceeding in another. A very common instance of mailing a judgment conclusive by consent, is where a party agrees, in consideration of delay, or some advantage to himself, to make the judgment of the court of common pleas conclusive, where, but for such consent, he would have a right to the judgment of the higher court.

But where the whole matter of law and fact is submitted, it may be open for the court to inquire into a mistake of law, arising from matter apparent on the award itself; as where the arbitrator has, in his award, raised the question of law, and made his award in the alternative, without expressing his own opinion ; or, what is perhaps more common, where the arbitrator expresses his opinion, and, conformably to that opinion, finds in favor of one of the parties; but if the law is otherwise, in the case stated, then his award is to be for the other party. In such case, there is no doubt, the court will consider the award conclusive as to the fact, and decide the question of law thus presented.

Another case, somewhat analogous, is where it is manifest, upon the award itself, that the arbitrator intended to decide according to law, but has mistaken the law. Then it is set aside, bécause it is manifest that the result does not conform to the real judgment of the arbitrator. For then, whatever his authority was to decide the questions of law, if controverted, according to his own judgment, the case supposes that he intended to decide as a court of law would decide; and therefore, if such decision would be otherwise, it follows that he intended to decide the other way.

Another ground for setting aside the award is a mistake of fact, apparent upon the award itself; and this is held to invalidate the award, upon the principle stated in the preceding proposition, that the award does not conform to the judgment of the arbitrators, and the mistake, apparent in some material and important particular, shows that the result is not the true judgment of the arbitrators. The mistake, therefore, must be of such a nature, so affecting the principles upon which the award is based, that if it had been seasonably known and disclosed to the arbitrators, if the truth had been known and understood by them, they would probably have come to a different resu.t. A. familiar instance of this class of mistakes, is an obvious error in computation, by which the apparent result, in sums or times, or other things of like kind is manifestly erroneous. In such case, it is clear that the result stated is not that intended; it does not express the real judgment of the arbitrators.

The class of cases in which the court will set aside an award, upon matter not arising out of the submission or award, is, where there is some corruption, partiality or misconduct on the part of the arbitrators, or some fraud or imposition on the part of the party attempting to set up the award, by means of which the arbitrators were deceived or misled. In neither of these cases is the result the deliberate and fair judgment of the judges chosen by the parties; the former is the result of prejudice, uninfluenced by law and fact; the latter may be a true judgment, but upon a case falsely imposed on them by the fraud of a party.

Under this class of cases, where the award may be set aside, upon matter not arising out of the submission or award, another was stated at the trial; that is, where the arbitrators make a mistake in matter of fact, by which they are led to a false result. This would not extend to a case where the arbitrators come to a conclusion of fact erroneously, upon evidence submitted to and considered by them, although the party impeaching the award should propose to demonstrate that the inference was wrong. This would be the result of reasoning and judgment, upon facts and circumstances known and understood; therefore a result which, upon the principles stated, must be deemed conclusive. But the mistake must be of some fact, inadvertently assumed and believed, which can now be shown not to have been as so assumed; and the principal illustration was that of using a false weight or measure, believing it to be correct. Suppose, as a further illustration, that a compass had been used to ascertain the bearings of points; and it should be after-wards found, that by accident, or the fraud of a party, a magnet had been so placed as to disturb the action of the needle, and this wholly unknown to the arbitrators ; it is not a fact, or the inference of a fact, upon which any judgment or skill had been exercised, but a pure mistake, by which their judgment, as well as the needle, had been swerved from the true direction, which it would have taken, had it followed the true law understood to govern it. One test of such a mistake is, that it is of such a kind, and so obvious, that when brought to the notice of the arbitrators, it would induce them to alter the result to which they had come in the particular specified. It is not to be un-de:stood that such mistake can be proved only by the testimony or by the admission of the arbitrators. They may, from various causes, be unable to testify, or may not be able to recollect the facts and circumstances sufficiently. It is not therefore, as matter of law, confined to a case of mistake admitted or proved by the arbitrators; but it must be of a fact upon which the judgment of the arbitrators has not passed as a part of their judicial investigation, and one of such a nature, and so proved, as to lead to a reasonable belief, that they were misled and deceived by it, and that if they had known the truth, they would have come to a different result.

With these general remarks, we will proceed more directly to the case under consideration. The Water Power Company have brought an action of covenant against Mr. Gray, to recover about $ 1400, being a proportionable part of the cost of a machine, directed to be set up, by the award of the commissioners, for the purpose of measuring the water used at his mills, and ascertaining the quantity. This is resisted by the defendant, on the ground that the award is not binding upon the parties, but is void, for several reasons specifically stated. If the amount sued for in this action were the whole amount involved .n the controversy, it would be of comparatively little importance. But the question, whether the award is valid or not, extends to other consequences, which are understood to be of much greater importar ce.

The objections of the defendant to the award are resolved into two classes, namely, 1st, departure from the authority vested in the arbitrators by the submission, and 2d, palpable errors and mistakes.

The power of the arbitrators, denominated, by the parties, commissioners, is to be sought in the submission; that being the instrument by which it was conferred. In expounding it, in order to ascertain the intent, every part of the instrument may be referred to; the preamble and recital, the lease referred to in the recital, the express delegations of power, and the several and respective covenants and stipulations. It recites a lease previously made to the defendant, by the Boston and Roxbury Mill Corporation, to whom the plaintiffs, the Water Power Company, had become successors by assignment. The Boston and Roxbury Mill Corporation, and also the Boston Iron Company, to whom the defendant had underlet a part of the premises, are made parties to the submission, rather, as we are to presume, to obtain their "assent to the proceedings, and bind them by the result, than because any claim was made by or against them.

By thus reciting the lease, and making it the basis of the proceeding, the whole lease, with all its provisions, grants and stipulations, is referred to, and makes part of the submission, as much as it it had been set out in words. These two instruments together constitute the submission. The recital is of some importance, by setting out what were understood to be the questions in controversy, and what was the purpose of the parties, in making the submission. It recites that questions and controversies had arisen between the parties, respecting the quantities of water, to which said Gray, and those claiming under him, are entitled, and the mode of measuring and delivering the sam©j and the quantities of water, which said Gray and others kai„ heretofore in fact used and enjoyed, and otherwise respecting the mutual rights and obligations of the parties, in regard to the nature and extent of the water power created by said basins and dams, and the manner of using the same; and recites also certain suits commenced and pending. The submission is then declared to be made for the purpose of determining said suits, controversies and questions, defining and limiting the mutual rights, powers and obligations of the parties, and regulating and securing the future enjoyment and fulfilment; of the same. Article 1st provides for the appointment of three commissioners, one of whom to be learned in the law, and the other two to be civil engineers, practically skilled in the measurement of water power, and learned in the scientific principles applicable thereto. It then proceeds to appoint Mr. Saltonstall as chairman, and Messrs. Baldwin and Hayward as associates, with a provision for supplying vacancies. Article 2d makes it tbe duty of tbe commissioners to determine wbat quantities of water said Gray, and those claiming under him, are entitled to draw and use, by virtue of said lease, and to determine the manner in which the same shall be measured and delivered, and to define and settle, in all other particulars, the legal rights of the parties under said lease. Article 3d requires them to determine the facts and principles on which claims for past deficiencies or excesses shall be determined; but not to determinethe amount of damages. Article 4th provides that the commissioners, having ascertained and defined, are to declare by their award, the legal rights of the parties, in respect to the premises and all other matters submitted to them, including the legal principles by which damages are to be assessed by another board of ref erees, for the appointment of whom provision is made in the, same instrument. Article 5th prohibits the company from leasing any more water power, without the license and permission of the commissioners, until a final award. Article 6th provides for restraining the company, in case of deficiency, from using tne water, so as to secure to the defendant his full powers pending the controversy, and until an award. Article 7th directs the time and mode in which the final award shall be made and published; declares that it shall be final and conclusive upon all matters embraced therein, under this submission, and stipulating that each party shall specifically perform whatever shall be directed to be specifically performed by such party

There are various other articles, providing for incidental matters, such as the appointment of assistants and apportionment of the expenses, declaring what parties are to be affected and barred by the award, providing for the reference of the pending suits to another board of referees, the constitution of such board, filling vacancies, and incidental provisions. One or two clauses in these provisions, by indicating the intentions of the parties, may bear on the general question. It is provided, that this second board is to decide according to ,the principles and legal rights of the parties, as established by the previous award of the commissioners, which is to be absolutely conclusive as to all matters which it purports to determine. So in a subsequent article, (12th,) such second set of referees shall settle and determine any principle of law, necessary to ascertaining the legal damages, provided such principle of law is not embraced in and determined by the previous award of the commissioners, and not in any respect repugnant to or conflicting with the principles established by the award of the commissioners, which are to govern, as aforesaid, in all matters therein embraced.

Such is this submission, apparently drawn under a distinct and comprehensive view of the nature and difficulties attending the inquiries to be conducted, and the controversies to be adjusted, and the provisions to be made, to prevent future contro versy; and with a manifest determination to make the decision conclusive. These judges, chosen by the parties, were perhaps designedly called commissioners, to indicate that they were invested with powers beyond those usually intrusted to arbitrators, in the ordinary administration of justice. That they were authorized to decide questions of law, does not depend upon implication arising from the appointment of a chairman who should be learned in the law; the power is conferred in express terms, and repeated again and again, as if to exclude the possibility of a doubt.

It seems equally clear, that every question of practical skill and of scientific principle, applicable to the subject matter, was intended to be conclusively determined, so far as they could affect the rights of these parties, upon the subject submitted to them, by their decision. And, in the opinion of the court, they were not only thus made the final judges of all questions of hew, of practical skill and science, coming directly in issue between the parties, but also of all collateral and incidental questions ; such as the admission and rejection of evidence, the manner in which all observations and experiments should be conducted, and the results reported, stated and compared ; and in general, as to the modes in which their inquiries and examinations «hould be conducted, availing themselves, according to their own judgment, of the testimony of others, of books, and of their own experience and observation. It seems therefore to follow, that, as no misconduct or partiality is imputed to them, but on the contrary, both at the trial and on the argument, studiously disclaimed, the only question which can arise is, whether these commissioners, in the award which they have made, have exceeded their authority, or been themselves misled and deceived by some inadvertent mistake of fact, of such a nature, that the award is not the result of their own judgment.

We proceed now to consider the several objections to the award, in the order in which they were submitted on the argument.

1. That the commissioners exceeded their power, in awarding that Gray should, in any event, be required to take the water, for his works, at a lower level than the third gate at the City Mills, as it stood at the time of the execution of the lease, it then being at 5.6 feet above the bottom of the wheel. It is contended that, although he had a right, as lessee, to take the water at a lower height, yet that he was not bound to do so.

This objection is founded upon the terms of the lease, and it proceeds on the ground, undoubtedly correct, that the lease and instrument of submission are to be construed together, in determining the powers of the commissioners. In referring to the lease, we find a description of what shall constitute a mill power. It is “ a quantity of water, equal to that which is now required, under any given head and fall, to grind, with one of the water wheels, and one pair of mill stones, at the grist mill of the company, as the same are now constructed and set up, eight bushels of rye, into good merchantable meal in one hour.” The whole is a description of a quantity of water,” at any given height of head and fall. The object was to ascertain a quantity of water which, under any head and fall, would constitute a mill power, that is, do a certain quantity of work. The words “ as now constructed and set up ” describe an actually existing mill; and the quantity required at that mill was the quantity intended. But it is to be drawn through convenient flumes, wherever he may choose, within the limits of the demised land. The right demised is, to draw a quantity .if water, the power of which shall be equal to ten mill powers. And in another clause it is expressly stipulated that the quantity or quantities of water, the power of which shall be always equal to the mill power or privilege before granted, shall be allowed to flow freely on the water wheels erected on the premises, and distributed in such proportions as said Gray, or his assigns, shall at any time require. The reference to the City Mills is solely to define the quantity of water which shall, at a given head and fall, constitute one such mill power; not to direct or limit the mode in which it shall be taken. Besides, we are strongly inclined to the opinion, that under a submission reciting that controversies had arisen as to the mode of using the water, and a submission is entered into, for the purpose of regulating and securing the future enjoyment of these rights, with full powers to the commissioners to construe the lease, it was competent to the commissioners to direct that the water should be taken at a lower level than 5.6 feet, if in their judgment such was the construction of the instrument, and such mode would secure the rights of the parties.

2. It is next objected to this award, as exceeding the authori ty of the commissioners, that they directed a measuring appara tus to be set up, in order to measure and ascertain the whole quantity of water used at Mr. Gray’s mills, at different heights of water in the full and empty basins, and in charging a part of the expense of this apparatus to him. Upon this point, it appears that it was stipulated in the original lease, that the lessee might at all times keep a gauge in any of the water courses on the premises, to regulate the power used according to the terms of said lease. The preamble of the instrument of submission recites that questions and controversies have arisen, respecting the mode of measuring and delivering the quantities of water, and the rights of the parties in regard to the nature and extent of the water power; and it is quite manifest, from, the whole terms of the instrument, that the lessee claimed that he had not had his due quantity, and the lessors claimed that he had taken a much larger quantity than he was entitled to under the lease; a diversity of claims, arising probably from the inadequate mode of gauging, or otherwise ascertaining it, in the mode then in use. One declared purpose of the submission to learned, skilled and scientific commissioners, was, to regulate the future enjoyment of the mutual rights of the parties. It empowers them, after determining the quantities of water which Mr. Gray, and those claiming under him, may draw, also to determine the manner in which the same shall be measured. When power is given to provide for the accomplishment of a certain end, it carries with it, by reasonable implication, the power to direct the means by which it shall be done; being judged to be suitable and proper. The commissioners state that there is no convenient method known to them, for measuring, before using the same, the quantity of water necessary to give the said eight mill powers ; and they then go on to direct how the said apparatus shall be erected, used and paid for. They manifestly proceed upon the conviction, that without some mode of measuring and ascertaining the quantity of water used by the lessee, all the other means, devised and directed for ascertaining the rights of the parties under the lease, would be unavailing, iij the regulation of the future enjoyment of their mutual rights. We think, therefore, that under an authority to direct how, in future, water and water power should be measured, with a view to its future enjoyment, they had power to direct that a proper apparatus should be erected and maintained, and, as incident thereto, to direct how the expense of erecting and maintaining it should be apportioned. In a recent case, a cause respecting a certain hedge, ditch and pump was in controversy between adjoining proprietors; and it was referred to an arbitrator to award how and by whom said pump, ditch and hedge should in future be occupied and enjoyed, and who should have the care and management of them. It was held to be within the power of the arbitrator to decide that the pump was the property of one, that the other should have the joint use of it to take water, and that the expense of repairs should be paid by them jointly. Boodle v. Davies, 3 Adolph. & Ellis, 200.

3. The next objection is, that the commissioners exceeded their authority, in making observations and experiments, at the mutual expense of these parties, to determine the whole number of mill powers, which the basins would furnish, being a question m which the defendant, as lessee of some of those powers, had no interest. But it appears to us, that this exception is not well taken, and that there are various grounds, upon which it was proper for the commissioners, as an incidental authority, to determine what was the whole water power of these basins; and that it is by no means apparent that the lessee had no interest in this inquiry.

The fifth article provides that the company shall make no more leases of water power, until the final award of the commissioners, without their permission and license. So in the sixth, it is provided, that if the commissioners, after hearing, shall find as a determinate fact, that said Gray and his assigns have not, at all times, had their full quantity of water, the commissioners may direct how and to what extent the company shall be restrained in their own use of the water, so as to preserve to said Gray the full use of his powers under the lease; and this may continue until the commissioners shall otherwise order, or til. the publication of their final award.

These clauses involve several necessary implications. The first is, a doubt whether the company could grant any further ’eases, consistently with the prior right granted to Mr. Gray; and the next clause implies a like doubt whether they had not already, by their own mills, and by leases to others, assumed to use more mill powers than could all be used at the same time, consistently with Mr. Gray’s prior right. And in both articles, which provide for temporary measures, during the pendency of the investigation, there is a clear and necessary implication that this is to be regulated by their final award. But it could not be known whether more sluices had already been opened, for supplying mill powers, than the basins could supply, or whether any, and how many, more might be opened, consistently with the full enjoyment, by Mr. Gray, of his full powers, without first ascertaining the capacity of the whole basins. The commissioners had power to award the specific performance of such things as they should judge necessary to the security and enjoyment of the rights of the parties. If more sluices should be opened than the power of the basins could supply, and supply at all times, they would have power to award, that certain of them should be closed, either permanently or at certain times of tide, so as not to interfere with the rights and powers of Mr Gray ; and the enforcing of a specific performance of such an award might afford a much more effectual security, during the long period for which his term is to continue, than any mere covenant or personal obligation of the lessors or their assigns could afford. It appears to us, therefore, that the commissioners did not exceed their authority, in proceeding, by observations and experiments, to ascertain and determine the number of mill powers which the said basins would afford, at any and every tide.

4. The next ground of objection is, that the commissioners exceeded their authority, in deciding that the Water Power Company should remove accretions from the basins; they not being the owners of the same. This is the sixth article oí the award, in which they express their opinion that the WaterPower Company have a legal right to enter on the receiving basin, and to remove obstructions to their water power, arising from accretions, and that they are legally bound to do so, whenever it shall be necessary to the full enjoyment of the privilege or mill powers granted to said Gray by the said lease. In the close of their report, they award and order that whatsoever is therein directed to be done by either of the parties shall be specifically performed by the said party. The two provisions together give to the lessee a new and more efficient remedy for securing the enjoyment of his rights. By the lease, the powers were granted to him, and perhaps some of the covenants would have given him a remedy by action for any detention of the rights granted; though it may be doubtful whether any of his covenants extended to secure him against a permissive diminution of his powers by obstructions in the basin. But suppose they would; a mere action for damages, after he had erected and completed extensive works, would have afforded but an inadequate remedy for the loss or gradual diminution of the power necessary to carry on those works. But the effect of the submission and award was not merely to assure him of the result, but to secure to him the specific means by which it was to be obtained. Now, if his right is impaired by accretions, diminishing the capacity of the receiving basin, he has a remedy, by which the specific power is restored, instead of an uncertain compensation in damages. But it is said, that, however beneficial, the commissioners could not order it, for this, among other reasons, that the company were not the owners of the soil. This does not appear; but suppose it be so, the commissioners find that in their opinion the company have a right to enter and remove such accretions ; and whether this results from absolute ownership, or from a right in nature of an easement appendant to their mills, and resulting from the grant of the Commonwealth or otherwise, is immaterial; it is equally in their power to do the act, equally beneficial to the lessee to have it done ; and thus it was within the authority of the commissioners to order it done.

But it is further argued, that if this duty was required at all, it should have been imposed upon the Boston and Roxbury Mill Corporation, because they were the original grantors and covenantors. True; but they had transferred the whole estate and interest, to which that covenant was incident, to the Water Power Company, and, for aught that appears, with the consent of the lessee. Besides; the whole rent, which is the consideration for those obligations of the lessors to keep the premises in a condition to yield rent, had been transferred to the Water Power Company, and it was equitable to lay the correlative duty upon them. At all events, there was sufficient ground to warrant the commissioners in exercising their judgment, in deciding what the rights of the lessee required in this respect.

5. The next alleged departure from their authority by the commissioners is, that they direct the water to be measured, after it has passed the mills, and not before. But it was nowhere stipulated that it should be so measured, and it cannot re suit from the trifling circumstance, that the word “ measured precedes the word “ delivered,” in the sentence. Even in the original lease, in which it was stipulated that the agents of the corporation might enter the premises, and examine the water courses, and keep a gauge there, it was not required to be either in the water course leading to the mills or from them; it was optional. It was, amongst other things, objected to this measuring apparatus, that it could not be used all the time, without great expense of men to watch it. But it may answer a useful purpose without being used all the time. As a ship’s log at sea may be used from time to time to ascertain the rate of a ship’s running, from which an average can be obtained for practica, purposes, so this apparatus may be used in various heights of the water, with more or fewer wheels running, from which a proximate average can be obtained. That it was intended so to be used, may be inferred from the provision, that it shall be so made as to be capable of being hoisted out, when not in use.

6. The last exception under this head is, that in deciding upon said Gray’s claim for damages, sustained before the submission, by reason of occasional deficiencies of water, the commissioners award, that he ought not to recover, because, in their opinion, it must have been understood by the parties, that the water power would necessarily be liable to occasional short deficiencies, from the manner in which it was created. It is said that the stipulation for ten powers was absolute, and without exception. It is certainly a well known rule of exposition, to construe stipulations according to the subject, with more or less latitude oi stiictness. But it is to be recollected, that in deciding upon these claims for past damage, to regulate another board of referees, the decision of these commissioners was to be absolute and decisive. They have decided against it. Suppose they have given an insufficient reason for it, it would show unsound ness of reasoning, not a defect of power. But in truth they have given two other reasons for it, either of which wo¿Id be decisive; namely, because the said Gray had enjoyed an excess over two and a half additional powers, as before stated, and pe cause of his acquiescence as aforesaid.

The defendant now relies upon another class of objection^ which are, that the award was invalid, on account of palpable errors and mistakes, either apparent upon the face of the award, or shown by evidence aliunde.

We have no doubt that the rule adopted at the trial was correct, by which it was held that an award, like the present, where all questions, both of law and fact, were referred, may be impeached and avoided by proof of fraud, accident or mistake. But it must be fraud practised upon the referees, or some accident or mistake, by which they were deceived and misled, so that the award is not, in fact, the result of their judgment. In a certain loose sense, the arbitrators may be said to have fallen into an error or mistake, a palpable mistake, when they have judged wrong upon the evidence before them. This is not the kind of error and mistake intended; because, so far as they have exercised their judgment, it is conclusive, though the result might, to otfer minds, seem palpably erroneous. In the case of Wood v. Griffith, 1 Swanst. 55, before Lord Eldon, where an arbitrator, in a case in chancery, had ordered the parties to join in a sale of an estate in controversy, although it was urged, that under the circumstances, the estate could not be sold advantageously, and that the order was unreasonable, and such appeared to be the strong leaning of the chancellor, yet he decided that the court would not inquire whether the award was unreasonable. Courts will not set aside an award, for mistake of the arbitrator, where the facts were placed before him, and he was competent to judge. Hardy v. Ringrose, 1 Har. & Woll. 185, as cited in 4 Harrison’s Digest, (Amer. ed.) 2296. The mistake or accident, therefore, must be of some fact which deceived and misled the arbitrators, and not a mistake in drawing conclusions of fact from evidence or observation, or mistake in adopting erroneous rules of law, or theories of philosophy. Several illustrations were given at the trial; and it may be well to mark the distinction intended, by another. Suppose it were referred to arbitrators to measure a large area, where it would be necessary to run lines through woods, by the aid of a compass. Suppose, through fraud or accident, a piece of steel had been so placed, near the compass, as to disturb the regular action of the needle, and this wholly unknown to the arbitrators, who were thus led to adopt false courses as true, as the basis of computation. If this fact could be afterwards proved, it would, we think, be good ground to set aside the award. But if they adopted a theory of magnetism, in regard to the actual variation of the compass, alleged to be erroneous, and leading to the adoption of a similar erroneous series' of courses ; although it should be pronounced erroneous by other philosophers, conversant with all that is known of the science of magnetism, whatever might be their number, or weight of authority, we think they could not be heard by a court and jury, because it would not tend to prove the kind of error or mistake, which had misled the constituted judges in the case, but would be an appeal from their decision in a case where they have exercised their judgment.

So, to put one more instance, suppose, in making mathematical computations, they had used tables of logarithms, believed by them to be correct, which are afterward shown to be erroneous. It would be a mistake that misled them. But if they adopted, purposely and deliberately, a process of mathematical reasoning which they believed to be correct, their award could not be impugned by the testimony of other mathematicians, tending to show that it was erroneous.

The rule adopted at nisi prius, for the purpose of this trial, was, as I have before intimated, that in showing gross errors and palpable mistakes in an award — using those terms as herein illustrated, explained and limited — by the law of this Commonwealth, the party impeaching the award is not confined to errors and mistakes apparent on the award; but that evidence might be given of any such plain, palpable mistake or gross error, though it was not apparent on the face of the award; that they might show, if they could, that the commissioners, through inadvertence or mistake, assumed a fact as true, which was not true, or overlooked some material fact, which was true, in either case affecting their decision.

As this part of the rule, admitting evidence to prove mistakes not apparent on the award, was favorable to the defendant, and therefore not excepted to by him; as the other party seeks to establish the verdict, and therefore had no cause to take any exception to this decision at nisi prius; it has not been brought under the consideration of the whole court, and not therefore affirmed by the decision in this case. In other respects, the court are of opinion that the rule adopted at the trial was correct.

We will refer to some of the errors and mistakes relied upon to invalidate this award.

The first is, that there was no allowance made for loss of read of water, in getting the water on to the wheels, and loss of power by the spilling out of water from the wheels, before its regular discharge.

After the fullest and most attentive consideration of the very long and laborious computations made at the argument, we cannot perceive any such mistake. In the first place, no fact was proved, showing that the commissioners were misled or deceived. Mr. Hayward, one of the commissioners, was called as a witness. He was asked what formula the commissioners adopted, by which they came to the result stated in the table. This question was objectionable, strictly speaking, because it assumed a fact not proved, but denied on the other side, viz. that the table was constructed by some formula which the witness had not stated. Regularly, he should have been first asked whether the table was constructed by a formula. But without placing any reliance upon this mere irregularity, the direct object of the question was to show what formula or "rule they adopted, by which the tables were constructed; that is, the rules, principles and deductions by which they prescribed the measures of mill power ; with a view to prove that such formula or rule was erroneous. The question therefore was clearly excluded by the rule adopted.

But the great effort has been, to convince the court, by extensive and laborious comparisons of one part of the table with another, that it is founded upon false theories either of hydraulics or of mathematics, and that it is founded upon rules which if carried out to their legitimate consequences, will lead to absurd conclusions. But in the first place, this is contradicted by the a.ward itself, in which the commissioners state, that these tables, to a certain extent, were the result of a long course of experiments, of observed facts, and deductions from them. But the more material and conclusive answer is, that the supposed error, whether it be of philosophical theory, or of mathematical deduction, was of a subject wholly submitted to the judgment of the arbitrators, and the conclusion was the result of their judgment; this is, therefore, an attempt to show that the com missioners judged wrong in a matter submitted to them. But as all such matters were submitted to their judgment, that judgment is conclusive, as well upon the court as the jury.

Another exception was, that the award was not made throughout from experiments, nor correctly deduced as the result of experiments. We cannot perceive the ground of this objection. The commissioners were authorized to resort to every other source of information, as well as experiments, and they state the conclusion as the result of their inquiries.

It is then stated, that during the experiments in grinding, made to ascertain a mill power, according to the standard prescribed in the lease, the mill stones were picked more frequently, and kept sharper, than their ordinary medium condition; by which less water was taken than if kept in that medium condition. If it had been in the power of the defendant to prove that the commissioners were misled or deceived as to the state of the mill stones, that is, if, in making their experiments, they intended to use the stones in their ordinary and medium state of sharpness, picked as frequently as usual, and not oftener, but through the fraud, officiousness, or even mistake of others, they were kept constantly sharp, and this unknown to the commissioners, it was quite open, by the rule adopted at the trial, to offer this evidence. But if the commissioners, knowing and directing the actual state of the mill stones, made their experiments under a belief that they were conforming to the standard prescribed in the submission and lease, then they passed their judgment on the subject how this clause prescribing the standard measure of a mill power should be construed, and that was conclusive. As the large sum of $ 1400 was paid for the use of the mills, for making these trials, the probability is that a large number of experiments were made, under almost every variety of condition, both of the height of water in the full and receiving basins, and of the condition of the mill and mill stones.

It is next alleged as a palpable error and mistake, that the commissioners took 54 pounds of rye, when the standard, fixed by law, is 56 pounds. We are not aware of any„proof of the fact, on which the exception rests. Besides, it was a question of construction as to what the parties intended by a bushel, and if the standard they adopted was not adopted through error or mistake, by which the commissioners were misled, the award is not to be avoided on that account.

Various other exceptions are taken, which I shall not now follow in detail. They are fully disposed of under some of the considerations already stated; and the court are of opinior that none of them is sufficient to avoid or set aside the award

One more objection seems to me to deserve notice. It was .god that the commissioners do, by implication, impair the rights of the lessee, by declaring that he shall be entitled to use his eight powers, so long as the said basins will furnish the same; whereas, by the lease, he is entitled to said powers absolutely, and without any such limitation.

It appears to us that this is founded upon a misconstruction of the terms of the award. The award is expressed in articles. By article 3d the commissioners express their opinion, and do award, that the said Gray, and those claiming under him, (not including Messrs. Boott and Lyman, who, we believe, had become assignees of two of the ten powers,) are legally entitled to eight full powers during the remainder of the term, to use and enjoy the same, at all times, by night as well as by day. This is the close of the article. Nothing could be more explicit, absolute and unconditional. The supposed limitation by implication is in the next clause, article 4th. By it, the commissioners express an opinion and do award that said Gray, and those claiming under him, are entitled to the use of said eight mill powers so long as the said basins will furnish the same ; and as between the said Water Power Company and said Gray, and those claiming under him, they have a legal right to be first fully served, to the extent of said eight powers; and that the company are legally bound to discontinue, and shall discontinue, their own mills, in part or altogether, so long as may be necessary to the full use and enjoyment of the mill powers belonging to said Gray.

Taking the two articles together, therefore, so far from an implication, limiting the right of said Gray, in the use of his mill powers, to such term of time only as the basins shall furnish the same, it awards to him, in terms, his full powers, for the whole term, at all times, and gives him a specific remedy for the enjoyment of them, by closing up the mills of the other party, if necessary; it secures to him the first right, as long as the basins will afford it. If the basins will not afford it, he cannot have it specifically ; but the award leaves to him the use and enjoyment of every other remedy, as fully as if this remedy for specific performance had not been awarded.

Judgment for the plaintiffs. 
      
      Hubbard, J. did not sit in this ca«p
     