Scientific American Supplement, No. 484, April 11, 1885 | Page 8

the cylinder, and, when fully compressed, ignition is effected by means
of the slide I have upon the table.
This system of ignition has been found very reliable, and capable of
acting as often as 400 times per minute, which the Otto ignite is quite
incapable of doing. By this cycle the advantages of compression are
gained and one step nearer to the steam engine is attained, that is, an
impulse is given for every revolution of the engine.
As a consequence, I am able with my engine to give a greater amount
of power for a comparatively small weight. In addition to this, I have
introduced a method of self-starting; in this I believe I was the
first--about 100 of my engines are now using self-starting.
The largest single engine I have yet made indicates 30 H.P. The
consumption of gas in Glasgow is: Clerk engine consumes in Glasgow
18 cubic feet per I.H.P. per hour; Clerk engine consumes in Manchester
22 cubic feet per I.H.P. per hour. So far as I know, the Otto engine and
my own are the only compression engines which have as yet made any
success in the market. Other engines are being continually prepared,
gas engine patents being taken out just now at the rate of 60 per annum,
but none of them have been able as yet to get beyond the experimental
stage. The reason is simply the great experience necessary to produce
these machines, which seem so very simple; but to the inexperienced
inventor the subject fairly bristles with pitfalls.
I have here sections of some of the earlier engines, including Dr.
Siemens' and Messrs. Simon and Beechy. Although interesting and
containing many good points, these have not been practically
successful.
The Simon engine is an adaptation of the well-known American

petroleum motor, the Brayton, the only difference consisting in the use
of steam as well as flame.
Dr. Siemens worked for some twenty years on gas engines, but he
aimed rather high at first to attain even moderate success. Had he lived,
I doubt not but that he would have succeeded in introducing them for
large powers. In 1882 he informed me that he had in hand a set of gas
engines of some hundreds of horse power for use on board ship, to be
supplied with gas from one of his gas producers modified to suit the
altered conditions.
Summarizing the ground over which we have passed, we find the origin
of the gas engine in the minds of the same men as were first to propose
the steam engine, Huyghens and Papin, 1680 and 1690. Greater
mechanical difficulties and ignorance of the nature of explosives
caused the abandonment of the internal combustion idea, and the
mechanical difficulties with steam being less, the steam engine became
successful, and triumphed over its rival. The knowledge and skill
gained in the construction of steam engines made it possible once again
to attack the more difficult problem, and simultaneously with the
introduction and perfecting of the steam engine, the gas engine idea
became more and more possible, the practicable stage commencing
with Lenoir and continuing with Hugon, Millein, Otto and Langen, F.H.
Wenham, then Otto and Clerk. In 1860, 95 cubic feet of gas produced
one horse power for an hour; in 1867, 40 cubic feet accomplished the
same thing; and now (1885) we can get one horse power for an hour for
from 15 to 20 cubic feet of gas, depending on the size of the engine
used.
Considered as a heat engine, the gas engine is now twice as efficient as
the very best modern steam engine. It is true the fuel used at present is
more expensive than coal, and for large powers the steam engine is the
best because of this. But the way is clearing to change this. Gas engines
as at present, if supplied with producer gas, produced direct from coal
without leaving any coke, as is done in the Siemens, the Wilson, and
the Dawson producers, will give power at one-half the cost of steam
power. They will use 7/8 of a pound of coal per horse power per hour,
instead of 1-3/4 lb., as is done in the best steam engines. The only
producer that makes gas for gas engines at present is the Dawson, and
in it anthracite is used, because of the difficulty of getting rid of the tar

coming from the Siemens and Wilson producers, using any ordinary
slack.
When this difficulty has been overcome, and that it will be overcome
there can be no manner of doubt, gas engines will rapidly displace the
steam engine, because a gas engine with a gas producer, producing gas
from any ordinary coal with the same ease as steam is produced from a
boiler, will be