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

510 ELECTRIC CURRENTS.
transmitted, cannot, therefore, give notice if a word has escaped
him; hence the necessity of suspending the transmission about
every ten words, and reversing the apparatus, to ascertain if
everything is understood, and if the words must be repeated
before going further. This is one cause of an immense loss of
time. And if the operator is not able to calculate the interval
of the pauses precisely, the confusion of the signals makes frequent repetitions necessary, which almost indefinitely prolongs
the duration of a dispatch. Finally, it is impossible to obtain
simple points from the instrument, for, in working rapidly, we
either get no signal at all, or a line; hence, Morse's alphabet,
instead of giving points and lines, is reduced to merely long and
short lines. This is enough to show the danger of confusion
and mistake.
To give an idea of the delay thus produced, it is only necessary to cite an example: A dispatch, consisting of 58 words,
and containing news from India, took more than five hours in
passing from Malta to Cagliari.
The causes of this have already been explained by Mr. Faraday, and proceed from the conditions of every cable, which performs the function of a Leyden jar; the copper wire forming the
internal armor, the gutta-percha and hemp make the insulation,
the iron wire and water serving as the external armor, in communication with the earth. The extreme length of the cable
gives it an immense surface, in spite of the fineness of the copper wire, and the interruption of the electric equilibrium which
takes place on every passage, or on every discontinuance of the
current by the reciprocal influence of the two armors and the
insulating substances, occasions the delays as well as the apparent anomalies of which I have spoken in the action of the
current on the telegraphic apparatus.
Another phenomenon quite important to notice-for it may
perhaps suggest the remedy for the defects inherent in submarine cables-is that the confusion of the signals and the transformation of the points into lines were incomparably more
numerous, when the telegraphic apparatus was attached directly to the end of the cable, than since the operation has been
performed at stations with the interposition of five kilometres
of wire on the land.
If the effects, of which I have stated the simple history, considerably obstruct the service of the Malta and Corfu lines,
they also show how far the fears are justified with regard to the
mischief they may produce on the far longer Atlantic cable,
and the necessity of profiting by the lines already existing for
the application of science to the correction of the difficulties.