Chicago Insulating Company experimenting with insulators

High-Resistance Insulators.

The Chicago Insulating Company has been for some time carrying on experiments upon insulators, and have tried every combination of materials and shape that theory and experience could suggest. Impressed with the importance of high insulation, they have not spared labor or expense, and their insulators show the result of original ideas and careful work.

Some of the patents owned by the company cover a new combination of materials from which they make knobs and insulators of great durability and resistance. To get an accurate idea of the value of this substance as an insulator, the company comployed Lieut. Bradley A. Fiske, who conducted a series of crucial tests upon knobs and insulators furnished by them. Using a Thomson reflecting galvanometer, Mr. Fiske tested not only for insulation, but for porosity and hygroscopic qualities, but failed to get any deflection of the spot of light. At length forty of the company's knobs were joined in multiple arc, and forty porcelain knobs of the same size were similarly joined, the result of the trial showing absolutely the greater insulation of the company's knobs. As a final test, water was abundantly sprayed upon both, and the resistance of each set again measured. The non-hygroscopic nature of the new material now asserted its advantages, for the company's insulators showed a superiority of the porcelain ones of exactly 50 per cent. As porcelain is less hygroscopic than glass, their superiority over glass insulators would have been still more marked.

As, however, glass is preferred by some, the company furnish insulators of glass embodying other features covered by their patents.

They also manufacture knobs for electric light conductors in a variety of forms and sizes, and in any color, to match the interior decorations of a building.

Among other interesting things manufactured by the company is a fire-proof insulating tubing for electric light wires, for which they received a medal at the great Railway Exposition at Chicago.

The company has just brought to perfection a new idea in insulators, particularly applicable to long lines, or wherever else a high resistance is important, by means of which the resistance of each insulator is increased nine times. They are not yet ready, however, to furnish them in quantities, but are rapidly making arrangements for manufacturing them upon an extended scale. These they make either of their compound above mentioned, giving a glossy black insulator, or of glass, as preferred. They have already received the indorsement of high authorities; and if they sustain the claim made for them, they will make a new departure in insulation, the importance of which can scarcely be over-estimated. We are promised further particulars at an early day, which we shall be glad to lay before our readers.