Mxhtbittid at Windsor. 515 
A brake trial of the engine was made, when the following 
results were obtained as compared with last year's engine : — 
Windsor. Nottingham 
Duration of trial 3-83 hrs. 2 hrs. 
Meau number revolutions per minute . 165-5 1G5-5 
Mean eH'ective load on brake wheel . . 114'6 lbs. 66'33 
Etlective diameter of brake wheel . . 3'8 ft. 6 ft. 
Brake horse-power ..... 6'38 4'48 
Petroleum consumed during trial . . 34'b8 lbs. lo'5 Iba. 
„ „ per brake horse-power 1-42 lbs. l-731bs. 
It will be noted at once that the consumption of petroleum per 
horse-power is less than at Nottingham, owing to the more per- 
fect combustion in the cylinder, the exhaust being quite clean 
and colourless. The uniformity of speed and the governing 
are very much improved. The maximum variation in speed during 
the above trial was from 154 to 157 revolutions per minute, 
which is very satisfactory. The price of petroleum is 6d. per 
gallon (the credit allowance for the cask may be taken as a set- 
off against carriage), the cost of petroleum per brake horse- 
power per hour being therefore I'Odd. as against lid. at Not- 
tingham. Of course, comparing the cost of fuel alone, in a 
petroleum engine and a steam engine, such comparison is 
unfavourable to the former. There are, however, other very 
important considerations. The petroleum engine, once started, 
requires little or no attention, there being no fire to keep up ; 
consequently the man is free to attend to other work. There is 
certainly less risk of fire, there being no sparks or unquenched 
ashes, and with a dense oil, such as used in this engine, there 
is no risk. But where a petroleum engine would actually 
come out cheaper in fuel consumption than a steam engine 
is in those cases where the engine is only used intermittently 
for a short time, there being no loss of fuel consumption in 
getting up steam, or waste of unconsumed fire at the end of the 
run. 
A second trial of this engine was made, running for five hours, 
at the same power and speed as before, but with the circulating 
pump connected up to a water cart, as would probably be the 
case when used as a portable engine on a farm. The capacity 
of the water cart was 450 gallons, the temperature of the water 
when first noted being 90° F., and five hours later 140° F, A 
tank of moderate dimensions will therefore serve to supply sufii- 
cient circulating water for some hours' work, mthout the addi- 
tion of any fresh water. This in many cases would be a matter 
of very great convenience. The principal advantage claimed for 
these engines is that the motive power is obtained from the com- 
mon petroleum of commerce; and not petroleum spirit, such as 
