[Trade Journal]
Publication: The Telegrapher
New York, NY, United States
vol. 1, no. 5, p. 47, col. 1
Description of the Ward Insulator.
An iron case is first provided in the shape of a truncated cone. A block of pine wood is turned into the same general shape, but of smaller dimensions which, after being boiled in oil, and varnished with shellac, is pinioned within the iron case by contact with lugs or elevations on the inner surface. An iron cap covers the upper end of the cone and is soldered tightly on.
Through the bottom end of the cone there is a round hole, one inch in diameter, where the hook passes up into the wood, and this is the only opening through the case. The insulating property is the dry prepared wood.
This wood is always kept dry, as it is situated in a dead air chamber formed by the case of iron. It is kept dry because there is no circulation through or into the dead air chamber. The insulator is as if a bottle were inverted, which would represent the dead air chamber, and a piece of prepared wood, were suspended in the bottle, to which the hook is attached.
Experiments show that condensation does not take place on the inside of the iron casing, and as a non conducting body (wood) is used for the insulating property its surface is always dry. Neither rain, fog, nor steam enters the chamber.
