Let a denote a deflection of the left-hand needle to the left, a´ to the right; b a deflection of the right-hand needle to the left, b´ to the right. Then here is the code:

+ a
A a a
B a a a
C a´ a
D a a´
E a´
F a´ a´
G a´ a´ a´
H b
I b b
K b b b
L b´ b
M b b´
N b´
O b´ b´
P b´ b´ b´
R a b
S a a b b
T a a a b b b
U a´ a b´ b
W a´ b´
X a´ a´ b´ b´
Y a´ a´ a´ b´ b´ b´

Thus F is indicated by two successive deflections of the left-hand needle to the right; R by a simultaneous deflection of both needles to the left. Where both needles are required they may be and are deflected simultaneously; where one only is used its deflections must of necessity be successive. The sign + means “I do not understand;” the letter E “I do understand.”

[34] It may interest our readers to reproduce the first published notice we can find of Professor Wheatstone’s experiments relating to the electric telegraph, and which appeared anterior to his connection with Mr. Cooke:—“During the month of June last year (1836), in a course of lectures delivered at King’s College, London, Professor Wheatstone repeated his experiments on the velocity of electricity which were published in the Philosophical Transactions for 1834, but with an insulated circuit of copper wire, the length of which was now increased to nearly four miles; the thickness of the wire was 1-16th of an inch. When machine electricity was employed, an electrometer placed on any point of the circuit diverged, and, wherever the continuity of the circuit was broken, bright sparks were visible. With a voltaic battery, or with a magneto-electric machine, water was decomposed, the needle of the galvanometer was deflected, &c., in the middle of the circuit. But, which has a more direct reference to the subject of our esteemed correspondent’s communication from Munich, Professor Wheatstone gave a sketch of the means by which he proposes to convert his apparatus into an electrical telegraph, which, by the aid of a few finger stops, will instantaneously, and distinctly, convey communications between the most distant points. These experiments are, we understand, still in progress, and the apparatus, as it is at present constructed, is capable of conveying thirty simple signals, which, combined in various manners, will be fully sufficient for the purposes of telegraphic communication.”—From the Magazine of Popular Science (Parker, Strand) for March 1, 1837.

[35]

a -
b - —— -
c —— - -
d - - - ——
e - -
f —— ——
g - —— - -
h —— —— ——
i - - -
j - - —— - -
k - —— —— -
l - ——
m - —— - ——
n - —— ——
o - - - -
p - - —— -
q —— - —— -
r ——
s —— -
t - - ——
u - - - - -
v —— —— -
w —— —— - -
x —— - - ——
y —— - ——
z —— - - -

[36] In justice to the Company, which is very properly jealous of the particulars of its messages transpiring, we beg to state that we acquired the above fact from a person totally disconnected with the Electric Telegraph Office.

[37] Mr. Reuter now performs this duty both for home and foreign news.

[38] The use of the metal or earth-plate will be understood from the following statement of Steinheil:—“Owing to the low conducting power of water or the ground, compared with metals, it is necessary that at the two places where the metal conductor is in connection with the soil, the former should present very large surfaces of contact. Assuming that water conducts two million times worse than copper, a surface of water proportional to this must be brought into contact with the water. If the section of a copper wire is 0·5 of a square line, it will require a copper plate of 61 square feet surface in order to conduct the galvanic current through the ground, as the wire in question would conduct it.”

[39] It may be as well to state that nearly all the continental telegraphs have formed themselves into a confederacy, called the Austro-Germanic Union, which includes the lines of Austria, Prussia, Saxony, Bavaria, Hanover, Würtemberg, the Netherlands, Denmark, and the Grand Duchy of Baden. The Union regulates the tariff and all questions relative to the working of the allied lines.