Page:Federal Reporter, 1st Series, Volume 4.djvu/229

 BEOADNAX V. CENTIUL STOCK YARD & TBAN3IT 00. 215 �the alleged invention was not new; and (c) because it was use- less and inoperative. Second, that the devices used by the defendants did not infringe. �If either defence prevail there must be a decree for the defendants. What is the complainant's patent? It has reference to mechanism or a combination of ingredients for the separation of grease or tallow from animal tissue or fiber. Two modes have long been in use for accomplishing this result — one by steam and hot water, -where the rough fût. or offal is put into a tank or kettle, and steam is injected in a sufficient quantity and temperature to liquify the fat; and the other by the application of dry external beat to the vessel containing the tissue or fiber, whereby the fat is melted and then drawn off in varions ways. One is known as the wet and the other as the dry rendering. Two of the defend- ant's expert witnesses, Quimby and Eeilly, agree that the former process is so much more efficient than the latter, in separating the fat from the animal fiber, that the residuum obtained requires a different treatment to prepare it for use. The elimination of the grease or tallow is so much more com- plete, that it is only necessary to evaporate the surplus water to have the residual mass fit for commercial purposes; whereas, by the dry process, so much of the fat stiU adheres to the fiber that loss would ensue unless independeut mechanioal treat- ment is resorted to, by pressure or squeezing, to remove the adhering fat before the scraps or cracklings are prepared for fertilizers. �The complainant has sought to remedy the practical incon- venience and expense resdlting from the need of these sep- arate processes for rendering and drying, by claiming in his re-issue such a combination of a heating chamber, tank, and stirrer that the material is rendered and the refuse dried in one continuons, process in the same apparatus. �In the original letters patent, the patentee, in stating the history of the art, describes both methods and suggests the principal objection to each. The object of his invention was to remedy these defects by furnishing a combination of instru- mentalities, ail of which were old, but claimed to be new in ����