ed in paint and dried. The
barbing and twisting together of the two longitudinal strand wires is done
by automatic machinery. A brief description of the manufacture of 2 and 4
point Glidden wire is as follows:--Two coils of wire on reels are placed
behind the machine, designed to form the main or strand wires of the fence.
One of the main wires passes through the machine longitudinally. One or two
coils of wire are placed on reels at either side of the machine for making
2 or 4 point wire respectively. These wires are fed into the machine at
right angles to the strand wire. At each movement of the feeding mechanism,
when fabricating 2 point wire, one cross wire is fed forward. A diagonal
cut forms a sharp point on the first end. The wire is again fed forward and
instantly wrapped firmly around one strand wire and cut off so as to leave
a sharp point on the incoming wire as before, while the bit of pointed wire
cut off remains as a double-pointed steel barb attached firmly to the
strand wire. This wire armed with barbs at regular intervals passes on
through a guide, where it is met by a second strand wire--a plain wire
without barbs. The duplex strand wires are attached to a take-up reel,
which is caused to revolve and take up the finished barbed wire
simultaneously and in unison with the barbing machine. In this way the
strand wires are loosely twisted into a 2-ply strand, armed with barbs
projecting at right angles in every direction.

When once started, the operation of barbed wire making is continuous and
rapid. The advantage of two strands is the automatic adjustment to changes
of temperature. When heat expands the strands, the twist simply loosens
without causing a sag, and when cold contracts them, the twist tightens,
all without materially altering the relative lengths of the combined wires.
A barbed wire machine produces from 2000 to 3000 lb of wire per day of ten
hours.

In some American states, the use of barbed wire is regulated by law, but as
a rule these laws apply to placing barbed wire on highways. Others prohibit
the use of barbed wire fencing to indicate the property line between
different owners, unless both agree to its use. In some states the use of
barbed wire is prohibited unless it has a top rail of lumber.

Barbed wire is also employed in connexion with "obstacles" in field
fortifications, especially in what are known as "high wire entanglements."
Pointed stakes or "pickets," 4 ft. high, are pla