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

THE STAGER COMPOUND CIRCUITS. 493
ing with a ground plate. In their course each of the main
lines may include at any point, or points, where stations are
required, receiving magnets, represented byR, R R &c., connected
in each instance with registers and the usual telegraphic apparatuses.
Mode of Operation.-The single battery, B, being in action,
any one or all of the apparatuses in the several main circuits,
may be used and operated in the same manner as though each
main circuit was a separate and independent circuit, supplied
with a separate and independent battery; and, herein consists
the novelty and utility of the improvement, viz.: A multiplicity
of circuits at even twenty or more, each extending several
hundreds of miles, can thus, be worked by means of a single
battery, instead of one to each circuit, as was practised previous to this improvement. In this use of a single battery,
according to the above described plan, there is no interference
of circuits, one with another; each performing its functions,
precisely as it would do if it were a complete and independent
circuit. Nor does the single battery, thus used to supply many
main lines, seem to be consumed faster than the single battery
of a single circuit as formerly used.
In case one or more of the main circuits be short, for example, 5 and 6, they need but a small voltaic force, and they
may be supplied by branches, starting out at intermediate
points of the battery, as at a and b. The voltaic force, thus
taken from a section of the battery, will not diminish perceptibly the current on the other main circuits.
It is a condition necessary to the success of this mode of
working, that each main circuit include a receiving magnet, or
a resisting wire equal to that of a relay magnet. There must
be no " cut off," or earth conductor, between the main battery
and a contiguous receiving magnet. If a circuit be thus made,
the battery force will be withdrawn from the other circuits,
and they may cease to operate effectively. If the earth connection be made beyond the receiving magnet, as at L, thus
compelling the electricity to traverse the fine wire of magnet R,
before reaching the earth, and returning to the prime ground
plate E, there will be no interference with the other main circuits,
though they may be of great lengths, and the other circuit very
short. This affords to the operator the advantage of working
one or more registers within the same station with the battery,
independently of all other registers, and without any interference with them.
In the plan as heretofore practised, of having a battery in
each circuit, the quantity of electricity generated, was more