Publication: The Electrical Engineer
New York, NY, United States
An Interesting Catalogue on Mica.
It is not often we have such a neat and interesting catalogue to look over as one lately received from the Mica Insulator Company. A short illustrated history of Mica, down from the times of Thales and Mahomet to those of the Anglo-Indian, opens the book. The illustrations in this article give a good idea of the Mica mines of India. There are strange looking ladders crowded with Hindoos passing up mica and water in baskets and jugs, other Hindoos sitting on their haunches, on the open ground, sorting and trimming the transparent crystal; bullock carts loading, and on their way down the mountains, and the mine owners' bungalow.
Micanite is then treated in a very exhaustive manner. It is shown how, by splitting and reassembling the raw laminations of the mica crystals the natural defects are overcome, and a homogeneous material produced. The tables given are useful and instructive. They include "Resistances," "Breakdown Voltages," etc.. of a large number of insulators. Other instructive articles have for their titles "Physical Properties of an Insulator," Armature Notes, Construction of Commutators and one relating to "Field Spools."
The business part of the catalogue includes all the specialties made by the company. Among others, micanite plate, flexible micanite plate, micanite cloth and paper, micanite commutator segments, micanite rings, armature troughs, washers, tubes, spools, cylinders, etc., all too well known to receive special mention. A striking feature — one that shows the extent of the electric railway business of the country, is the fact that a list of complete commutator insulators for fifty-one types of street railway motors is given. Space is also given to the other materials manufactured by the company, including "Empire" oiled papers and cloths, linen and asbestos, etc., and similar materials treated with their "M I C compound." We can advise all electrical engineers interested in the improvements made in electrical insulation to send for this catalogue. They will find it both instructive and useful.
|Keywords:||Mica Insulator Company|
|Date completed:||April 26, 2011 by: Bob Stahr;|