Page:International Library of Technology, Volume 93.djvu/130

 pressure is proportional to the absolute temperature; and, if the mixture of gas and air at atmospheric pressure and temperature is burned, the pressure resulting from this heating might be four or five times as great as atmospheric pressure.

19. If the products of combustion could be stored at the temperature of the flame, and if it were practicable to deliver them to an engine in this condition, it would be possible to burn the gases in a separate chamber and deliver the hot compressed gases to the engine as they are used. There are two reasons why this cannot be done. In the first place, the extremely high temperature of the gases would destroy any valve or other apparatus controlling their admission to and exhaust from the cylinder, and would burn any lubricating oil that could be fed to the piston. The other reason is

that it has been found necessary to compress the gases before igniting them in order to use them most economically, and a separate machine of the dimensions required for compressing the gases would consume so much power that