The telegraph manual: a complete history and description of the semaphoric, electric and magnetic telegraphs of Europe, Asia, Africa, and America, ancient and modern.

150 RONALD'S ELECTRIC TELEGRAPH.
sons, let the tubes be buried six feet below the surface of the
middle of the high roads, and let each tube take a different
route to arrive at the same place. Could any number of rogues
then open trenches six feet deep, in two or more different public
high roads or streets, and get through two or more strong castiron troughs, in less space of time than forty minutes? for we
shall presently see that they would be detected before the expiration of that time. If they could, render their difficulties
greater by cutting the trench deeper, and should they still succeed in breaking the communication by these means, hang
them if you catch them, damn them if you cannot, and mlend
it immediately in both cases."
In further explanation Mr. Roland states, that the circular
brass plate, fig. 2, was divided into 20 equal parts, and it was
fixed upon the seconds' arbor of a clock which beat dead seconds. Each division was marked by a figure, a letter and a
preparatory sign. The figures were divided into two series,
from 1 to 10, the letters were arranged alphabetically, leaving out J, Q, u, w, x, z. The preparatory signs are indicated
by the position of the rays indicated by A, B, c, D, E, F, G, Hn I, K,
and represent as follows, viz., A, prepare; B, ready; c, repeat
sentence; D, repeat word1; E, finish; F, annul sentence; c, annul word; H, note figures; i, note letters; K, dictionary.
Before and over the disk, fig. 2, was fixed a brass plate, fig.
3, capable of being occasionally moved by the hand round its
centre, and which had an aperture of such dimensions, that
while the disk was carried round by the motion of the clock,
only one of the letters, figures, and preparatory signs upon it
could be seen through the aperture at the same time; for instance, the figure 9, the letter v, and the sign " Ready," are
now visible through the aperture in fig. 3. In front of this
pair of plates, A, fig. 1 and 4, was suspended an electrometer
of Canton's pith balls, from a wire E, which was insulated, and
communicated with a cylindric electrical machine of only 6
inches in diameter, and with the wire c 525 feet long, which
was insulated in glass tubes, surrounded by the wooden trough
filled with pitch, and buried in a trench cut 4 feet deep in the
ground.'Another similar electrometer was suspended in the same
manner before another clock, similarly furnished with the same
kind of plates and electrical machine. This second clock and
machine were situated at the other end of the buried wire, and
it was adjusted to go as nearly as possible synchronously with
the first. Hence, it is evident, that when the wire was charged
by the machine at either end, the electrometers at both ends