Evans and Woodward patent incandescent lamp (1874–1879)

Mathew Evans and Henry Woodward filed a Canadian patent for an incandescent electric light bulb on July 24, 1874, in Toronto. Their device used carbon rods in a nitrogen-filled glass cylinder. Although they lacked funds to commercialize the invention, they sold the patent rights to Thomas Edison in 1879. The Canadian government credits them with the invention, though Edison's later work established the first practical system.

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Background and detail

Background. Henry Woodward, a Canadian inventor, and Mathew Evans, a hotel keeper, collaborated on an incandescent lamp. Their specific design involved carbon rods mounted in a nitrogen-filled glass cylinder. This work preceded Edison's U.S. patent by five years, establishing an early claim to the invention of the electric light bulb.

Patent Process. The pair filed their Canadian patent application on July 24, 1874. The patent was granted on August 3, 1874, as Canadian patent number 3,738. The drawings in Woodward's subsequent 1876 United States patent were almost identical to those in the 1874 Canadian filing. This early patent was purchased by Edison during his investigations, prior to his own patent grant.

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