Bright idea

American inventor Thomas Edison is usually credited with inventing the electric light bulb, but in fact Edison based his creation on a patent he purchased from a couple of Canadians.

Medical student Henry Woodward and hotel keeper Matthew Evans were neighbours in Toronto who spent winter evenings in 1873 experimenting with batteries and induction coils. Noticing that light was created by a spark at the conduction post, they found a way to contain the light inside a glass tube with a carbon-filament rod connected to two wires. Their prototype proved more effective than any form of electric light that had previously been developed.

Woodward and Evans patented the invention but were unable to find investors, so in 1879 they sold the patent to Edison for $5,000. Edison then applied his own improvements to their prototype to make it longer-lasting and more commercially viable.