employed, and this is being done. Also room is left for increasing the
length and wearing surfaces of all the main bearings with even less
crowding than is now the case with engines with the smaller cylinders.

But this advantage of saving room comes much more prominently forward in
marine engines, especially in war ships, where every inch of room saved is
valuable; and in the new type of triple-cylinder engines now coming so
much into vogue in the mercantile marine, whether those engines be only
the ordinary three-cylinder engines with double expansion, or the newer,
triple expansion engine, expanding the steam consecutively through three
cylinders--the form of marine engine which promises to come into use
wherever high-class work and economy are required. On this system, by
placing all the valve chests in front of the cylinders instead of between
them, or in a line with them, sufficient room is saved to get the new-type
three-cylinder engine into the space occupied by the old form of
two-cylinder engine.

Besides these prominent advantages there are others which, though of minor
importance, are still necessary to the practical and permanent success of
any new mechanical arrangement, such as the accessibility of all the
working parts while in motion, for examination and oiling; the ease with
which any part or the whole can be stripped and cleaned, or pinned up out
of the way in case of break down or accident, or got at and dismantled for
ordinary repair; the ease with which the whole may be handled, started,
reversed, or set at any point of expansion--all these being
recommendations to enlist the care and attention of the engineers in
charge by lightening their duties and rendering the engines easy to work.

With those advantages it is perhaps not surprising that this valve gear
has been very considerably adopted for many classes of steam engines,