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

NOTTEBOHN S PARATONNERRE. 577
the philosophy of each is the same. The American paratonnerre, fig. 6, passes the current immediately to the earth;
Steinheil's carries it on to the next station, though it is certain
to be dissipated from the wire within a few miles, and perhaps
none of the plus charge will ever reach the next station in
course. Mr. Meisner made the base of his contrivance a part
of his circuit to the earth or of the line. The American improvement on Steinheil's plan, fig. 8, would lead the wire a a
b to the apparatus, and thence to the earth, or on to the next
station, but not by way of plate pr. From plate p' the American plan is to conduct a wire immediately to the earth, and
no other wire would be connected with plate p'. The same
remarks may be applied to the arrangements invented by Mr.
Meisner. In the use of fig. 10, arranged as above described,
the American telegrapher attaches the line wire L to plate A,
and by 1 through the apparatus, and then it is extended on to
the next station. An earth wire is fastened to plate B; this
completes the arrangement, as represented by fig. 6. In this
combination the voltaic current traverses the line wire, through
the magnet coils, and thence on to the next station or to the
earth, as desired by the telegrapher. The lightning will not
pass through the fine wire of the magnet, but will leap from
plate A to plate B. If the line is extended through the office
to the next station, a paratonnerre will have to be placed for
the line on each side of the apparatus in the station.
NOTTEBOHN S PARATONNERRE.
The director-general, Nottebohn, of the Prussian government lines, devised a novel combination for a paratonnerre.
Fig. 13 represents the arrangement employed in the stations
of the Prussian telegraphs.
Between the two pointed copper or brass cones, u q, is a
Fig. 13.
double pointed copper marked o k, with its points nearly
touching the points of u and q. The copper piece o k is con37