Johnson and Phillips Oil Insulator

THE CONVERSAZIONE OF THE SOCIETY OF TELEGRAPH ENGINEERS.

Among the apparatus exhibited at South Kensington we noticed some that was new, and some that has not been described in our columns. We shall therefore as opportunity offers refer to these exhibits.

JOHNSON AND PHILLIPS' EXHIBITS.

Patent Fluid Insulators. - (See engraving.) - The patentees interpose between "Line" and "Earth" an insulator containing a fluid which will not support a film of dust or moisture upon its surface. In this way "surface leakage" is quite prevented, a very important feature in damp and marshy districts, along the sea coast, where insulators soon become coated with a conducting film of salt, or in the neighborhood of towns or manufacturing districts, where carbon is deposited upon the surface of the porcelain. Messrs. Johnson and Phillips exhibited an insulator which had been fixed for ten months over a chimney, and was perfectly coated with carbon all over. Before testing it was thoroughly wetted with a jet of steam, when its insulation was found to be perfect, while an ordinary insulator fixed beside it gave "dead earth." There is no doubt, say the makers, that by care a land line might be made in this way to give an insulation quite equal to that of a gutta percha core, a very important fact in connection with duplex working, where every shower will greatly alter the resistance of the "Line," when insulated with the ordinary insulators. Colonel Champain is giving these insulators a trial on the Mekran Coast, and has spoken well of the invention. The General Post Office also, and the French telegraph authorities are giving them a trial.

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