212 Life and Letters of Francis Galton
which must puzzle the onlooker unacquainted with that , strange mixture of Stuart and Barclay, of Colyear and Darwin blood.
The first sign of the reawakening of the old tastes is the endeavour of Galton in 1849 to design a printing telegraph. The account of this instrument was printed in 1849, but post-dated in the publication June 1850, two months after Galton had left for Africa. The pamphlet gives very extensive details of the mechanical parts of the apparatus. In order to appreciate what the "telotype" meant in those days, we must remind the reader that telegraphy, then recently introduced into this country, was not carried on by the Post Office but by a number of commercial companies, and a printing telegraph had not yet been achieved. Galton's instrument looks cumbersome with our modern experience of tape instruments, but there are some ingenious ideas involved. How far it was ever actually constructed it is now perhaps impossible to say, but from the wording it might be supposed that portions at least had been actually made ; Galton speaks of the instrument as the result of many experiments', and dealing with his method of intensifying the mechanical effect of the slight touch of a needle he writes
" It is very interesting to watch such a series in operation ; how the delicate, scarcely perceptible touch of the first arm causes an influence that travels on, almost as if by instinct through the whole series ; how each arm hands it to the one beyond it ;
its available power increasing at each delivery 2."
If the whole or parts were constructed, they do not appear to have been. preserved, or at least to have reached the Galton Laboratory with the long series of his models and other instruments, which we possess. Galton's telotype involves three wires to connect sending and receiving stations. The needle of a galvanometer may remain stationary, turn to right or turn to left. Thus each wire can send three signals, or the system of three wires 27 signals, enough for the complete alphabet. Now consider a lever in the form of a rectangular frame balanced about a median line or axis; suppose a key slightly longer than the parallel sides of the rectangle turning on the same axis, then if the frame be horizontal and the key pass over the perpendicular edge of the side of the frame it will depress it, when itself depressed. The depression causes contact
1 The Telotype : a printing Electric Telegraph, by Francis Galton, Esq., M.A., Trin. Coll., Cambridge. John Weale, 1850, p. 32.
2 Ibid., p. 10.