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EXPLANATION OF THE PLATES.
Fifth, as the internal parts of the engines are kept so much longer in repair owing
to the causes above mentioned, the perpetual expense and time required in repairing
such parts is greatly diminished; indeed there is no doubt but the slides, valves, pistons,
and all the internal parts of the engines are in much finer condition after having been
in operation for years, than they are the first day they are set to work. The
circumstance of salt being carried over with the steam into the cylinders (when salt
water is used in the boilers) is unquestionable, as well as that it is the cause of the
valves and other internal parts of the engines becoming so soon in bad condition,
whereby a great waste of steam takes place even long before they become so very
much worn as to render it indispensably necessary to give them a thorough repair.
The regulation of injection water, and of the water to supply the boilers, forms no
part of the duty of the engineer, as they are quite superseded by no injection taking
place, and the boilers being self-supplied with undeviating accuracy.
It may also be observed, that the comparative advantages of the patent engines do
not appear to be so great on the first starting of new engines, or even during the
first month or two, as the boilers and machinery of injection engines, are then as
clean and in as good order as those of the patent engines ; but afterwards, when the
boilers of the former become thickly coated with scale, the internal parts of the
engines are worn and galled, while those of the latter are actually improved, and the
comparison should then be made.
Lastly, it is certain that a vessel with the patent engines of 300 horse power,
will effect an increase of economy and advantage of £2500 or £3000 per annum
over a vessel having injection engines of that power, and consequently the former
will realize so much greater a profit.”
The following engines are now in operation with the improvements applied to them:
The Sirius steam ship with a pair of engines of 320 horses’ power, both included,
on the station from London to New York, being the first steam vessel that performed
that voyage across the Atlantic and back. This vessel belongs to the St. George
Steam Packet Company, and is chartered by the British and American Steam Navi
gation Company.
The Meqcera steam ship with a pair of engines of 140 horses' power, stationed
in the Mediterranean, and built by the Lords Commissioners of the Admiralty
for her Majesty’s navy. Engravings of her engines are given in this work, Plates
XLIX., L.
The Hercules steam vessel with a pair of engines of 180 horses’ power, stationed
between Glasgow, Dublin, and Cork, belonging to the St. George Steam Packet Com-
pany.
The Sea-horse steam vessel with a pair of engines of 260 horses’ power, stationed
between Hull and Eotterdam, belonging to the St. George Steam Packet Company.