
    THE HARVEY STEEL COMPANY, THE MIDVALE STEEL COMPANY INTERVENING, v. THE UNITED STATES.
    [46 C. Cls. R., 298; 227 U. S. R., 165.]
    
      On the defendant's and the Midvale Steel Company's appeal.
    
    This is a suit between the same parties and upon the same contract as that reported in 38 C. Cls. R., 662, 681; affirmed, 196 U. S. R., 310; viz, to recover royalties under an express contract for the use of the Harvey process in hardening armor plate. The inventor is the manufacturer who used the process. He seeks to defeat a recovery upon the ground that sand was not packed on the back of the armor plates as a nonearbonaceous material, and hence that the process covered by the claimant’s patent and contract with the defendants was not used.
    The court below decides:
    I. Where the only difference between the present suit and one previously decided in favor of the claimant is that in former cases the hardening of armor plates was effected by using sand as nonearbonaceous material bn the back of the plates and in the present case carbonaceous material was confined within the brick box inclosing the plates; the change is technical, the use of sand not being essential to the Harvey process.
    
      II.That the manufacture of armor plates for the Government was not an infringement of the patent is not a defense which can be set up by the Government under the former decisions of this and the Supreme Court. The Government having received the benefit of the process under its contract with the claimant is liable to the claimant therefor.
    III. When the action is upon the contract between a patentee and the Government by the terms of which the Government becomes expressly liable for royalties where the patented process is used in the manufacture of armor plates for one of its vessels, it can not compel the patentee to look for payment to the manufacturer who employed the process.
    IV. The court reiterates the principle formally announced in its decision in the previous case that where, by the terms of the contract, the defendants are entitled to a disclosure of the inventor’s process and to his instructions and assistance in the practical application of the invention in whole or in part, deviations therefrom can not be set up as a defense.
    The decision of the court below is affirmed on the same grounds.
    February 3, 1913.
   Mr. Chief Justice White

delivered the opinion of the Supreme Court  