
    Gage Structural Steel Company, complainant and appellee, v. O’Brien Brothers Construction Company et al., defendants. Material Service Corporation, intervening petitioner and appellee. Sanitary District of Chicago, appellant.
    Gen. No. 37,039.
    Opinion filed June 15, 1934.
    William Rothmann, for appellant; Edward A. McCarthy, Senior Assistant Attorney, of counsel. A. S. and E. W. Froehlich and Joseph Chavkin, for appellees.
   Mr. Justice Gridley

delivered the opinion of the court.  