With 30 years of glass making experience James Madison Brookfield left Pennsylvania and moved to Brooklyn NY in the early 1860's. He was hired by a brewer named Martin Kalbfleisch who needed a manager for a glass factory he had purchased in 1864 called the Bushwick Glass Works. James was successful and ended up buying the company in 1869.
As time went by the proliferation of the telegraph and telephone systems created a huge demand for glass insulators. At some point James' son William came into the business and was most probably placed in charge of the insulator side of the operation. By the 1880's most of the production at the Brookfield Co. shifted from bottles and jars and was now mainly glass insulators.
One day a carpenter named Louis A. Cauvet showed up at the Brookfield office to show off his invention of a threaded pin system to solve the problem of the insulators coming loose from smooth pins. James and Martin had gone to lunch and left the chief clerk in charge. The clerk dismissed the idea as foolish but when the Brookfields heard the story they realized what a good idea it was and sent for Mr. Cauvet right away. Meanwhile Louis, uanable to be found by the Brookfields, spent a couple weeks trying to sell his invention to other insulator makers but nobody was interested. Finally the Brookfields located Mr. Cauvet and promptly purchased the rights to his patent. Cauvet's idea revolutionized the glass insulator and the Brookfield threaded glass insulator soon became the standard.
Most glass insulators have some kind of embossing. This is writing that is cut into the molds to display various information on the finished insulator. These embossings often relate style or mold numbers, The manufacturer's name or even the company or utility that purchased the insulator. Today these markings are of great use to historians and collectors because it helps to identify the use and to date different pieces.
My "Brookie" shown above has the following embossing:
55 FULTON ST. NY
FEB 22 1870
JAN 25 1870
JAN 14 1879
In the 57 years the Brookfield Company produced glass they made over 100 different kinds of insulators. The only company that probably made more insulators than the Brookfields was Hemingray. James Brookfield retired in 1880 and William carried on until his death in 1903. The books were officially closed on the company in Sept. 1922. Think about that. This was a factory in Brooklyn with coal fired furnaces with men making stuff. One of many industries fueling a rapidly growing economy as information and people expanded to every corner of young America.
Click on the picture and check out the bubbles on the lower part of the insulator- the skirt. The embossed dates are just about visible on the dome. I took this picture in direct sunlight. It really makes them sparkle.