The insulator represented in the annexed engraving was originally
designed to meet the requirements of South American telegraph service,
but it is equally well adapted to lines in other places. The main idea
is to avoid breakage from expansion and contraction in a climate subject
to sudden changes of temperature, and to avoid the mischief occasioned
by a well known South American bird, the "hornero," by building nests of
mud on the brackets and insulators. With this insulator these nests
cannot cause a weather contact or earth; on the contrary, the nest
rather improves the insulation. The sectional view, Fig 2, shows the
construction of the insulator and the manner of fastening it to the
cross arm or bracket. A rubber ring is placed between the upper end of
the porcelain insulator and the cross arm, and another similar ring is
placed between the head of the suspending screw and the bottom of the
insulator. It will be noticed that with this construction the insulator
cannot be broken by the contraction of the screw or by the swelling of
the cross-piece. This insulator can be used on an iron bracket and in
connection with either iron or wooden posts, and is in every way more
secure than the insulators in common use. The first cost of these
insulators compares favorably with the cheapest in market, while it is
less liable to breakage, lasts longer, and gives better results. It has
been patented in this country and in Europe.
[Illustration: IMPROVED TELEGRAPH INSULATOR.]
Further information maybe obtained by addressing Mr. J. H. Bloomfield,
Concordia, Entre Reos, Argentine Republic, South America.
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