Marie Killick

Marie Louise Killick (in some sources Maria, 1914–1964; née Benson) was an English audio engineer who patented the truncated-tip sapphire stylus in 1945 for playing gramophone records. The tradename of her invention was Sapphox.

Early life Killick's father, John, was an engineer. He trained her in precision engineering as a young girl. Killick studied sound recording in Antwerp.

Inventions During World War II, she worked for the army making sound equipment (steel cutters for master recordings on wax discs). She borrowed £300 from a bank to start a business producing more and was awarded a contract with the War Office. She made cutters for recordings on the battlefields and designed a portable recorder for them to use.

At the time, recordings were played with steel needles that could destroy the record. Killick invented a stylus using a sapphire or diamond gemstone. Her stylus had better sound quality and did not damage the record because it would ride the sides of the record groove, not the bottom. She filed her patent application on 25 October 1945 and was granted a full Letters Patent, No. 603,606 on 18 June 1948.

Her stylus was marketed under the name Sapphox and was manufactured in London. However, her bankruptcy in the following year prevented her from profiting from the outcome which could have been in the millions.

She died in Guildford, Surrey, England, at age 49, with no money and homeless.

Personal life Marie had four children. Her daughter, Cynthia, has written a book about her mother's experience, including how she was kidnapped and forced to live in a builder's yard with her children as a result of tactics used to try to scare her from continuing her legal fight against Pye.