Before HASTINGS, Chief Judge, DUFFY and CASTLE, Circuit Judges. CASTLE, Circuit Judge: Radiant Burners, Inc., plaintiff-appellant, (herein called plaintiff) a manufacturer of conversion gas burners and gas furnaces brought suit in the District Court seeking recovery of treble damages from and injunctive relief against defendants-appellees.Plaintiff's second amended complaint charged defendants with conspiracy and combination, in violation of 15 U.S.C.A. Â§ 1, for the purpose of controlling the manufacture, sale, use and installation of gas burners and gas heating devices and restraining the trade and commerce of manufacturers of such devices in a manner thereinafter described. The defendants-appellees are American Gas Association, Inc., (herein called AGA); Peoples Gas, Light & Coke Co. and Northern Illinois Gas Company (herein called Utilities); Natural Gas Pipeline Company of America and Texas-Illinois Natural Gas Company (herein called Pipelines); Autogas Corporation, Crown Stove Works, Florence Stove Company, Gas Appliance Service, Inc., Norge Sales Corporation and Sellers Engineering Company (designated in the complaint as Manufacturers). It is alleged that AGA is a membership corporation and its membership embraces (1) public utility corporations, including Peoples and Northern; (2) hundreds of manufacturers of machinery, equipment and devices used in the collection, transmission and distribution of gas; (3) pipeline companies transmitting gas to utilities and large industrial users; and (4) individuals and other legal entities.