which is place a back pressure valve to retain the pressure in the
combustion chamber. The engine is regulated by an ordinary Porter
governor actuating the throttle valve, O. An engine, as described, has
been constructed by Messrs. Adair & Co., engineers, Waterloo Road,
Liverpool, and has been running most satisfactorily for several weeks,
the results being clearly shown by the indicator diagrams (Figs. 5 and
6). The results obtained by this motor are very remarkable, and are a
long way in advance of any previous performance, as only a little over ½
lb. of fuel is used per i.h.p. per hour. It may be mentioned that the
temperature of the combustion chamber is calculated to be about
2,500°F., and that of the exhaust gases does not exceed
180°F.--_Industries._

[Illustration: Diagram from cylinder--25 in. diam, 18 in. stroke.
I.H.P., 63. Scale, 1/30 in. Mean pressure, 28.2 lb. FIG. 5.]

[Illustration: Diagram from air pump--15 in. diam., 18 in. stroke.
I.H.P., 23. Scale, 1/30 in--Mean pressure, 28.5 lb. FIG. 6.

DIAGRAMS FROM CYLINDER AND AIR PUMP.

Net indicated horse power, 40; revolutions per minute, 100; coal tar
consumed per hour, 20.5 lb.; coal tar per I.H.P. per hour, 0.512 lb.]

* * * * *




AN INVESTIGATION INTO THE INTERNAL STRESSES OCCURRING IN CAST IRON