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

658 TELEGRAPH CROSSINGS OVER RIVERS.
The river is but 62 feet broad at high water, and then nearly
level with its banks.
The masts, one on each bank, each of two spars, are 150 feet
apart, and 100 feet above ground. The lower mast is 1 foot in
diameter, 70 feet above ground, into which it penetrates 10
feet, and is stepped in a buried frame of two beams, crossed at
a right angle, each 20 feet long, 6 inches square, the ends connected by four timber pieces, strengthened at the angles by
wrought iron straps and bolts. There are four timber struts,
each 12 feet long, one from each end of the cross piece, bolted
to the mast, 2 feet below the ground. For the attachment of
the stays, there are four piles at equal distances, each 8 feet
from the mast, 1 foot square, 12 feet long, shod with iron, and
provided with iron caps and bolts. A stay of one inch iron
rope leads from the top of the lower mast to each of these
piles.
The top mast is thirty-six feet long, and thirty feet above
the lower mast; the compound mast being one hundred feet
above the ground.
A cross stay of iron wire rope runs from mast to mast, 7 feet
below the top. Two stays, also of iron wire rope, lead from the
same part of the mast to two piles 60 feet from the lower mast,
and of the same dimension as the other piles. The top mast is
secured by four stays of iron wire rope, attached to cross-trees
in the usual mode of mast rigging.
A spindle and vane, serving also as the point of a lightning
conductor of iron rope, completes the mast.
The telegraph conductors are six wires of No. 8 galvanized iron
of the best kind. They are led through brown stoneware insulators, attached to the mast at its highest part, and above the
stays. The wires are strained tight, and led, each set, to a
telegraph post one hundred feet from the mast, and thirtyfive feet high. From these posts the wires join the lines at
each side.
Instead of the expensive and troublesome plan of framing for
the underground work above described, in India they employ
the screw piles, six feet long. These piles carry a lower mast
35 to 40 feet high. Four of the ordinary small piles, 3 feet
long, are first screwed into the ground, each at 20 feet from the
spot where the mast is to be erected. The mast fitted in its
pile is raised into its position, and steadied, tent-pole fashion, by
four rope guys lashed, as required, to a short spar in the smaller
pile; four loops of iron wire on an iron plate fitting loosely on a
pin in the mast, serve for the attachment of the guys, and keep
the mast perpendicular, while it is screwed into its place. This