How does the 1874 electric light bulb work?

Be it known that We, Henry Woodward of the city of Toronto in the County of York, in the Province of Ontario Medical Electrician, and Mathew Evans also of the city of Toronto, in the County of York, in the Province of Ontario Gentleman, have jointly invented:

New and useful improvements in the art or process of obtaining Artificial light by means of Electricity and we do hereby declare that the following is a full clear and exact description of the same.

In the first place we use a gas engine, or other suitable motive power, for the purpose of rotating a magneto Electric Machine, and at Such Velocity, as shall create electricity, sufficient to heat certain pieces of Carbon to a state of incandescence.

In the Second place, we use pure Carbon and place the same in lamps, or outer suitable vessels, as hereinafter described.

A piece of Carbon, as hereinbefore mentioned, pure in quality, and of suitable size, proportionate to the size of lamp or vessel to be used, is scraped and shaped until fitted for the purpose. One electrode is then Connected with the Carbon at the top, and the other electrode is connected with the Carbon at the bottom, in the following manner. A small hole is drilled a short distance into each end of the Carbon to fit the electrodes, and when necessary they are further secured by surrounding them with a portion of plaster of Paris or other suitable substance. The electrodes not passing through the carbons, nor Connecting with each other. It is then enclosed in a globe, or other vessel, either of glass or other Suitable material. The air is then extracted from the said globe, or vessel, after it has been hermetically sealed at the ends, and then filled with rarified gas that will not unite chemically with the carbon when hot. Electricity is now supplied and in sufficient quantity, so as to heat the carbon within the vessel to a State of incandescence, the rarified gas previously introduced now becomes luminous, and constitutes the light herein designated as Woodward and Evans' Electric Light.

This process will give a light of any required intensity, and there is practically no limit to the number of lights that may be obtained from one Magneto Electric Machine.

http://www.mysteriesofcanada.com/Ontario/first_electric_light_bulb.htm

First answer by ID1075474437. Last edit by Poojat. Contributor trust: 2 [recommend contributor]. Question popularity: 10 [recommend question]