Cruto incandescent lamp; Brass Cap, with split brass peg

Cruto first showed one of his lamps at the Munich Exhibition of 1883. It had a filament made by depositing carbon on a platinum wire and then vaporising the platinum. He claimed this made it more efficient than other types, though this proved difficult to substantiate. The lamp does not seem to have been a success; in any case it probably infringed other people’s patents. The Cruto Company apparently continued to exist, but as a manufacturer of perfectly ordinary carbon filament lamps.