705 
The Trials of Oil Engines at Cambridge. 
diagonal plate, down which it runs and is vaporised. An adjust- 
ment is provided by which the quantity of oil at each charge can 
be regulated, and the valve-box is filled by gravity from a raised 
tank. This arrangement is secure against injury from dirt, as 
anything which is small enough to pass into the oil-plug would 
simply fall to the bottom of the vaporising chamber and there 
be retained. The lamp which heats the vaporiser is com- 
pletely enclosed in a cast-iron combustion chamber, the blast 
being supplied by an air-pump. 
This engine is substantially, even clumsily, constructed, of 
good material and workmanship, but would lose nothing by 
more refinement and outward finish of details. 
Fig. 5.— Section through cylinder and vaporiser of Weyman & Hitchcock’s “Trusty ” Oil Engine 
A. Cylinder. E. Pump. 
B. Combustion chamber. F. Main air supply. 
c. Oil inlet. I. Lubricator. 
D. Sight feed tube. 
The makers claim that little, if any, “ gasification ” takes 
place, as the vaporiser is water-jacketed, and so not overheated. 
This view is to some extent upheld by the fact that the cylinder 
works without lubrication, beyond that of the condensed oil 
vapour. 
Messrs. Weyman & Hitchcock, Ltd., Guildford. — Messrs. 
Weyman & Hitchcock’s engine, the “ Trusty ” (5 brake horse- 
power, 133/.), has a vaporiser which is heated by the explosion 
and exhaust products alone. But, unlike that of the Hornsby’ 
engine, it is a separate chamber within the combustion space. 
It is illustrated, in section, in fig. 5. At starting it requires to 
be heated by a temporary lamp, but the heat of explosion and 
exhaust subsequently maintains it at the required temperature, 
