The invention and later perfection of the telegraph by Morse in 1844 created an immediate need for line insulators.  Although glass insulators were rapidly developed for this use, there are some references to "flint" or "porcelain" insulators having been used on telegraph lines as early as about 1853.  There also exist a number of specimens reputedly recovered from military lines constructed in the late 1860-1880 period.

When the telephone was introduced by Alexander Graham Bell in 1877, insulators were soon required in very large quantities.  Railway signal systems had also been developed by this time largely as the result of relay techniques developed for the telegraph systems.  The glass insulators had reached a state of development by that time where they could be made cheaply in large quantities, and they generally performed satisfactorily for signal use.

In 1881, Thomas Edison invented the incandescent lamp and in 1882 he installed a 1200-horsepower generator in a New York warehouse and began furnishing power to "subscribers" for operation of electric lights.  Existing telegraph lines with glass insulators were used in this distribution network.  The average citizen considered these newfangled lights just a fad and a dangerous one at that.  When the City of Syracuse, New York was considering the installation of 148 electric street lights in 1882, an alderman introduced a motion "that all poles be enclosed by a 10-foot high wood paling fence in order that pedestrians would be protected from the dangerous electricity that would run down the poles on wet nights".

The following year, a New York grocer became the first person to use transmitted electric power for a purpose other than lighting when he hooked an electric motor to Edison's line and connected it to his coffee grinder.  The first electric railway came into use in 1885 when Richmond, Virginia converted 12 horsedrawn trolley cars to electric motor driving.  The "fad" was spreading.

As demand for electric power rose rapidly in the 1880's, the line loss became a limiting factor.  The D.C. voltage running into the subscriber's homes could not be further increased, since serious electrical shocks were already a problem.  But there was a solution.  Why not use an Alternating Current (AC) system, wherein transformers can be used to step up or step down line voltages as required?  The power can be generated at a low voltage, stepped up for distribution, and then stepped down again for use by the customer.

The first AC system in this country using transformers was put into operation in 1886 at Great Barrington, Massachusetts.  Even a moderate step-up of the distribution voltages held line losses to practical values.  but it wasn't long before a different problem came up.  The glass insulators in use had reached their insulating limitations.  It was at this time that larger glass insulators were designed for power distribution.  Fred M. Locke of Victor, NY started in the business of selling ones made to his design by the glass insulator manufacturers of the day.  Distribution voltages quickly rose to the limits of these king-sized glass insulators.

© 2006 - Risley House.  All rights reserved.

Reference Credits
Jack H. Tod, Porcelain Insulators, Guide Book for Collectors  (Unipart Pin Types), Third Edition, Pages 7-10