er darkness. A blacker night there
could hardly be; looking ahead there is nothing to be seen but one's own
reflection in the weather-glass. We are in the midst of obscurity, which
suddenly changes to a rich light as the whistle is opened and we enter a
tunnel. The effect is far more striking than in the daytime. The light is
more concentrated, and the mouth of the tunnel we have just entered might
be the entrance to Hades--for there is no telltale spot of light to prove
to our senses the existence of any opening at the other end. The sound
echoed from the walls and roof has a tremendous quality, and resolves
itself into a grand sort of Wagnerian rhythm, making a vast crescendo,
till with a rush we clear the tunnel, and are once more under the open
sky. The pace is increasing, the steady beat of the engine tells more
distinctly on the ear than in the daytime; the foot-plate is lit up by
the glare from the fire-door; but still there is nothing to be seen ahead
but the impenetrable night. Looking back, however, the scene is very
different. The tender and guard's van glow in the light thrown by the
fire, trees and houses by the side of the track stand out sharply for a
moment and are then lost to sight, the light from the carriage windows
produces the effect of the wake of a ship seen from the stern. Gradually
the clouds have rolled away, leaving the sky clear. The moon is seen
fitfully through the whirling steam; the surrounding country is visible
for miles round. The effect produced is unspeakably beautiful. In the
mean time let us turn our attention to the working of the engine. In the
first place, let us take note that, although the engine we are now on,
and that which took us from London, belong to the same type, their
performances are somewhat different. No two engines ever resemble each
other, no matter how carefully they may have been built from the same
plan, neither do any two drivers manage their engines precisely in the
same way. We have in this instance an excellent opportunity of comparing
two different methods of driving. It is the driver's principal object to
get the required amount of work out of his engine with the smallest
possible expenditure of coal and water. To obtain this result the steam
must be worked expansively, which is done by placing the valve gear in
such a position by means of the lever that the supply of steam to the
cylinders is cut off, as we have stated at the beginning of this article,
b