TUOKEB i;. BABUBNT. . 301 �ment,) and then plaee it in an oven, where it is submitted to a degree o£ beat which may be measured by an intensity sufflcient to change a brightened sur- face of clean, unoiled iron to a color varying from a light straw color to a deep blue; the lowest degree of beat producing the lightest colored changes andthe lightest bronze, and the highest degree of beat producing the darkest colored changes and the darkest bronze. It is important that the coating of oil be made extremely thin, as a coating of auy material thickness will leave a rough and varied surface after the beat is applied. As the oiled iron becomes beated the color obtained will be bronze, of an intensity corresponding to the degree of beat employed; but it should be observed that the beat may be made so intense and so long continued as to destroy the oil, in whlch case the iron will lose the bronze tint acquired and will assume the dark-blue Shade." �The defendant is said to have infrdnged the two reissues by the man- ufacture and sale of cast-iron butts, samples of which -were produced and marked Exhibits A D and DD. These butts were colored in this way: The sunken parts are first coveredwith a blackjapan, and this coat of blacking is baked in an oven at a temperature not exceeding 320 deg. Fahrenheit. This japanning of the sunken parts is immar terial. It is not really claimed to be a Tucker bronzing; the object, probably, is to make a marked contrast between the sunken and salient parts of the butt. Ail but the sunken parts are then ground and subjected to a beat of 480 deg, Fahrenheit, which colora the iron a dark straw color. The ground parts of one of the exhibits are nearly or quite blue. A coat of oopal vamish of substantial thick- ness is then put on and baked in a beat of not over 300 deg. Fahren- heit. This produces a material coating of oxidized varnish upon the surface of the iron which can be scraped up by a rapidly-drawn knife- blade, as a shaving rolls up before the knife of a plane. It was not claimed by the defendant that the vamish was not oxidized by the beat. No proof was offered by the plaintiff in regard to the oxida- tion of the iron during the second heating, and I do not think it of importance. The plaintiff relies upon the uncontradicted fact that by successive applications of beat the iron and varnish were oxidized ; and if an iron surface oxidized by beat with a coating of vamish oxidized by beat necessarily makes Tucker bronze, then the defend- ant infringes the plaintiff's patents. This precise question bas not apparently been the subject of discussion, either before Judge Clifford or Judge Lowell, and therefore it becomes necessary to ascertain the exact extent of the invention by the aid of the evidence v?hich was introduced in regard to novelty, and which the defendant insisted proved that the Tucker process was practiced in its factory prior to 18-59. ��� �
