Scientific American Supplement, No. 312, December 24, 1881 | Page 9

of the amalgam chamber at each
operation. Fresh water, therefore, was needed; the problem arose how
to get it; and that problem was solved, not by the use of surface
condensation, but by the employment of reinjection, that is to say, the
water delivered from the hot well was passed into pipes external to the
vessel; after traversing them, it came back into the injection tank
sufficiently cooled to be used again. The boilers were worked by coke
fires, urged by a fan blast in their ashpits, but I am not aware that this
mode of firing was a needful part of the system.
LOCOMOTIVE ENGINES.
I come now to the engines used for railways. At the British Association
meeting of 1831, the Manchester and Liverpool Railway had been
opened only about a year. The Stockton and Darlington coal line, it is
true, had carried passengers by steam power as early as 1825, but I
think we may look upon the Manchester and Liverpool as being the
beginning of the passenger and mercantile railway system of the
present day. At that time the locomotives weighed from eight to ten
tons, and the speed was about 20 miles per hour, with a pressure of
from 40 to 50 lb. The rails were light; they were jointed in the chairs,
which were generally carried on stone blocks, thus affording most
excellent anvils for the battering to pieces of the ends of the rails--that
is to say, for the destruction of the very parts where they were most
vulnerable. The engines were not competent to draw heavy trains, and
it was a common practice to have at the foot of an incline a shed
containing a "bank engine," which ran out after the trains as they
passed, and pushed them up to the top of the hill. Injectors were then
unknown, and donkey-pumps were unknown, and therefore, when it
was necessary to fill up the boiler, if it had not been properly pumped
up before the locomotive came to rest, it had to run about the line in
order to work its feed-pumps. To get over this difficulty, it was
occasionally the practice to insert into a line of rails, in a siding, a pair
of wheels, with their tops level with that of the rails so that the engine
wheels could run upon the rims. Then, the locomotive being fixed to
prevent it from moving off the pair of wheels thus endways, it was put
into revolution, its driving wheels bearing, as already stated, upon the

rims of the pair of wheels in the rails, and thus the engine worked its
feed-pumps without interfering (by its needless running up and down
the line) with the traffic. It should have been stated, that at this time
there was no link motion, no practical expansion of the steam, and that
even the reversal of the engine had to be effected by working the sides
by hand gear, in the manner in use in marine engines. When the British
Association originated, although the Manchester and Liverpool
Railway had been opened for a year, there is no doubt that the 300
members who then came to this city found their way here by the slow
process of the stage-coach, the loss of which we so much deplore in the
summer and in fine weather, but the obligatory use of which we should
so much regret in the miserable weather now prevailing in these
islands.
In 1881, we know that railways are everywhere inserted. Steel rails,
double the weight of the original iron ones, are used. Wooden sleepers
have replaced the stone blocks, and they, in their turn, will probably
give way to sleepers of steel. The joints are now made by means of
fish-plates, and the most vulnerable part of the rail, the end, is no
longer laid on an anvil for a purpose of being smashed to pieces, but
the ends of the rails are now almost always over a void, and thereby are
not more affected by wear than is any other part of the rail. The speed
is now from 50 to 60 miles an hour for passenger trains, while slow
speed goods engines, weighing 45 tons, draw behind them coal trains
of 800 tons. The injector is now commonly employed, and, by its aid, a
careful driver of the engine of a stopping train can fill up his boiler
while at rest at the stations. The link motion is in common use, to
which, no doubt, is owing the very considerable economy with which
the locomotive engine now works.
As regards the question of safety, it is a fact that, notwithstanding the
increased speed, railway accidents are fewer than they were at the slow
speed. It is also a fact, that if the