Lanyon

Appellee brought suit to obtain an injunction restraining appellant from making, using, or selling any furnace construction embodying the inventions disclosed in the Beall and Foltz patents, both of which are owned by appellee. Appellant asks review of the decree which granted the relief sought by appellee. The patents involved relate to furnace construction.

Witness Nathan E. Lewis, a mechanical engineer, testified on behalf of appellee, and related a part of the history and problems connected with the present day furnaces. It appears that between the years 1910 and 1915 stokers were introduced for use with boiler furnaces, which “permitted the burning of a greater amount of coal per square foot of grate and permitted the generating of more steam from the heating surface under the installations in which they were installed.” At the time of the introduction of these stokers, the boilers were installed with the heating surface located from six to seven feet above the fuel bed.

When stokers were used with these so-called “low-set installations,” it was difficult to obtain a smokeless combustion “due to imperfect combustion and cramped space.” This materially reduced the efficiency…