When Glenn Powers graduated from Kent Law School in the late 1920s, no one whispered a "magical word" to him about the future demand for materials. In fact, according to his son, Jim, it was a "lousy time to be a lawyer", so he found work at Western Electric Company.
As he began to develop an understanding of the electrical industry, Glenn Powers also practiced his chosen profession, and assisted a client that owned several North Carolina Mica mines. Glenn traded his expertise for a partial ownership in the mining interests and found himself on the ground floor of a soon-to-burgeon industry.
That stroke of luck had nothing to do with magnetics. Instead, Glenn became part owner of an enterprise mining and processing Mica in North Carolina and subsequently owning the Buster mine, the largest Mica mine in the world in the 1940s, in the Dakotas.
In 1941, the Perfection Mica Company opened offices in downtown Chicago in the Civic Opera Building, the "architectural masterpiece of the age" at the time. World War II drove the demand for Mica in the 1940s. Electron tubes required it, as did early electrical appliances, such as toasters. Because mica is transparent in thin layers, it was used during wartime in the eyeholes of gas masks, road goggles, and armored car peepholes. Its resistance to heat allowed it to be used instead of glass in windows for stoves and kerosene heaters.
Mica has a high dielectric strength and excellent chemical stability, making it a favored material for manufacturing capacitors for radio frequency applications. It has also been used as an insulator in high voltage electrical equipment. It is also birefringent and is commonly used to make quarter and half wave plates.
Large deposits of the "wonder mineral" as Mica was known then, were discovered in Africa, South America and India in the 1950s. Values dropped as production costs increased, making Mica mining less than a desirable business.
With the decline in the price of Mica, and a concurrent lessening of demand as other technologies were developed, Glenn Powers and his partner in Perfection Mica began an earnest search for their next enterprise. Designing and producing shields for magnetic interference was the solution settled upon, and by the mid 1940s, both Mica products and magnetic shields were being produced in the factory on North Elston Avenue in Chicago
By the mid-1950s, magnetic shields overtook the Mica business, and Magnetic Shield Corporation officially became the primary enterprise in 1956.
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