712 The Trials of Oil Engines at Cambridge. 
The vaporiser is shown at C in fig. 12. Oil is supplied from 
the pump through the pipe A to the centre of the large air valve 
B. A portion of the air enters with the oil into the centre of 
the vaporiser, while the greater portion passes outside a non- 
conducting casing D and through the combustion chamber, 
cooling the latter so as to prevent pre-ignition, and mingles with 
the mixed air and vapour as it enters the cylinder. On the 
return compression stroke the vapour ignites against the hot 
vaporiser. At the commencement of exhaust a small valve opens 
and discharges the hottest portion of the exhaust through the 
vaporiser, thus heating it afresh. This then closes, and a second, 
larger valve discharges 
the remainder through 
thecombustion chamber. 
The air valve is 
opened automatically on 
the suction stroke. The 
inertia governor acts 
upon the exhaust valve, 
keeping it open, where- 
by the air valve fails to 
act and a charge is 
missed. 
The engine is ex- 
tremely compact and 
neat, and runs at 286 
to 300 revolutions per 
minute, developing 4i 
brake horse-power. 
At starting, the 
vapoi’iser is heated by 
a hand spirit-lamp for 
five to ten minutes, and 
starts away very easily. 
The circulation through the -water jacket is produced by 
a pump driven off the crank shaft. The oil ordinarily used in 
this engine is Tea Rose oil, and the adjustments not being 
suitable for Russolene oil, difficulty was experienced in keeping 
the vaporiser hot enough. The engine was therefore withdrawn 
at the end of the second day’s run. Experience w r ith the use 
of Russolene oil may be expected to overcome these difficulties, 
and the engine certainly deserves praise for its particularly quiet 
running and for the ingenuity as well as simplicity of its work- 
ing parts. This is obtained partly at the expense of accessi- 
bility, and one would perhaps hesitate before placing it in the 
Fig. 12.— Section through vaporiser and combustion 
chamber of Tolch & Co.’s “ Capitaine ” Engine. 
