730 
Proceedings of the Royal Society 
11. Note on the Wire Telephone as a Transmitter. 
By James Blyth, M.A. 
It was shown some time ago by Dr Ferguson, and more recently 
by Professor Chrystal and Mr Preece, that a fine wire attached to a 
mechanical telephone can act very well as a receiver in a telephonic 
circuit, provided a make and break, or some form of microphone 
transmitter, he employed. None of these experimenters, however, 
have said anything about the action of such a wire as a transmitter. 
Being struck by the convertibility, in general, of all forms of tele- 
phone receivers into transmitters, and vice versa, it occurred to me 
to try how far this wire telephone, as it has been called, could be 
made to act as a transmitter to an ordinary Bell telephone as 
receiver. I was much interested to find that it could act in that 
capacity wonderfully well, as thereby a new element of some im- 
portance is introduced into the discussion of the real cause or 
causes of the action of the wire telephone whether as receiver or 
as transmitter. 
In my first experiments a battery of four Bunsen cells was 
included in a telephone circuit of small resistance. At the sending 
station, which we shall call A, an arrangement was made whereby 
different lengths of various kinds and thicknesses of wire could be 
inserted in the circuit. At first these wires were inserted by being 
soldered to the copper terminals, in order to keep clear of loose 
contacts ; but it was afterwards found that all error arising from 
this source could be avoided by simply clamping the wires firmly 
between two binding screws. This method, from its greater con- 
venience, was therefore afterwards adopted. To the middle of the 
inserted wire, and at right angles to it, was attached a fine iron wire 
about 15 inches long, the other end of which was connected to the 
centre of the parchment disc of a mechanical telephone. When 
this wire was stretched moderately tight the transmitting arrange- 
ment was complete. At the receiving station, which we shall call 
B, an ordinary double-ear Bell telephone of small resistance was 
employed. 
When a fine iron wire about 9 inches long was inserted in the 
circuit at A, any musical sound uttered into the mechanical tele- 
phone was most distinctly reproduced at B. Speech could also be 
