_To the Editor of the Scientific American_:

I send you a plate of my new railway signal wire compensator. Here
in India signal wires give more trouble, perhaps, than in America or
elsewhere, by expansion and contraction. What makes the difficulty more
here is the ignorance and indolence of the point and signalmen, who
are all natives. There have been numerous collisions, owing to signals
falling off by contraction. Many devices and systems have been tried,
but none have given the desired result. You will observe the signal wire
marked D is entirely separated and independent of the wire, E, leading
to lever. On the Great Indian and Peninsula Railway I work one of these
compensators, 1,160 yards from signal, which stands on a summit the
grade of which is 1 in 150; and on the Nizam State Railway I have one
working on a signal 800 yards. This signal had previously given so much
trouble that it was decided to do away with it altogether. It stands on
top of a high cutting and on a 1,600 foot curve.

[Illustration: Railway Signal Wire Comensator]

I have noted on the compensator fixed at 1,160 yards, 131/4 inches
contraction and expansion. The compensator is very simple and not at all
likely to get out of order. On new wire, when I fix my compensator, I
usually have an adjusting screw on the lead to lever. This I remove
when the wire has been stretched to its full tension. I have everything
removed from lever, so there can be no meddling or altering. When
once the wire is stretched so that no slack remains between lever and
trigger, no further adjustment is necessary.