New-York tribune., 1906-12-02
MARINE GAS ENGINES.

The tests of American coal which have been
made by the United States Geological Survey,
and which are described in Washington dis
patch printed on another page of The Tribune.
will serve at least two good purposes. BY deter
mining the heat generating power and other
qualities of different grades of fuel produced in
this country they will assist the intelligent
buyer In learning how 10 get the most for his
money when procuring coal for steam plant.
They will also emphasize the economy which.
under certain conditions. is attainable by using
gas engines This latter possibility is at present
better appreciated in Europe than In America
It Is now a well established fact that more
power can be derived from ton of coal by
converting it into gas and exploding the product
behind q piston than by employing 1t for the
development Of steam. The output in the for
ner case is about two and half times as great
as In the latter with small engines. AS the
size of the two classes of machine increases the
advantage perceptibly diminiShes. but COM
parison has yet been made which shows the
gain to be less than 100 per cent. Fully to
double the power to be had from given guam
tity of fuel is unguestionaby great advance,
and one which be turned to account in
many industries.
Hitherto the benefits to be secured by In
stallng gas engines have been enjoyed only on
land. 1t was natural, however. that the ques-
ton of utilizing them at well should
receive careful consideration by progressive
shipbuilders. If the space required on mer-
chant vessel for fuel could be reduced onehalf,
there would be a corresponding gain In room for
freight and an increase in earning capacity.
On fighting ship the principle would be ap-
piled in different fashion. The size Of the
bunkers might not be reduced. but the radius of
action would be doubled-a consequence Of i'm
mense strategic value. So few years ago
Cor Topit itoSn TO oda M tha
gas engine to marine service. and, though slow
progress has thus far been made, the problems
involved are being studied with earnestDess and
ingenuity, If not with enthusiasm.
When the task was once undertaken 1t was
perceived that a marine gas engine would re-
quire a number OF accessories that are not de-
manded by steam engine. Special devices for
reversing and pumps for circulating water
around the cylinders are among the essentials
Of successful operation These and other items
Of the equipment add to the space demanded by
the machinery and to the expense Of providing
1t. Some Of them call also for the exercise Of
inventive talent, and there Is yet no assurance
that this has been adequate to the emergency.
Modest experiments are still being made In
England If not elsewhere with Capitaine's
IDEAS and 1t Is reasonable TO hope that eventu-
ally success will be attained.
Aside from the reasons already given for not
cherishing oversanguine expectations at pres
ent there is another worth mentioning. No
gas engine for power plants on land has yet
been built whose capacity is comparable with
that of the biggest steam engines now In SER
vice. There are probably not half dozen gas
engines In this country capable of developing
5000 horsepower. In the rotation Of each of
her two propeller shafts the steamship ST. Paul
expends 1900 or 10000 horsepower. the Cam
pana 1900 or 15OGo, the Deutschland $4,000
and the Kaiser Wilhelm II not less than &C, 900