more wire spirals could be fixed between the rails at any convenient
distance from the signaling station, so that when necessary intermittent
currents could be sent through the spirals; and another spiral could be
fixed beneath the engine or guard's van, and connected to one or more
telephones placed near those in charge of the train. Then as the train
passed over the fixed spiral the sound given out by the transmitter
would be loudly reproduced by the telephone and indicate by its
character the signal intended.

One of my experiments in this direction will perhaps better illustrate
my meaning. The large spiral was connected in circuit with twelve
Leclanche cells and the two make and break transmitters before
described. They were so connected that either transmitter could be
switched into circuit when required, and this I considered the signaling
station. This small spiral was so arranged that it passed in front of
the large one at the distance of 8 in. and at a speed of twenty-eight
miles per hour. The terminals of the small spiral were connected to
a telephone fixed in a distant room, the result being that the sound
reproduced from either transmitter could be clearly heard and recognized
every time the spirals passed each other. With a knowledge of this fact
I think it will be readily understood now a cheap and efficient adjunct
to the present system of railway signaling could be obtained by such
means as I have ventured to bring to your notice this evening.

Thus have I given you some of the thoughts and experiments which have
occupied my attention during my leisure. I have been long under the
impression that there is a feeling in the minds of many that we are
already in a position to give an answer to almost every question
relating to electricity or magnetism. All I can say is, that the more
I endeavor to advance in a knowledge of these subjects, the more am I