The Combustion Egg Timer looks a cross between an oil lamp and a chiming clock.
It is made of brass, copper and steel, and mounted on a polished mahogany base.
There is a brass fuel reservoir, a steel combustion cup, a spark mechanism and a large brass bell.
To operate, the user pulls back the
spring-loaded striker on the bell until it latches, using a catch resembling a traditional mousetrap. They then press a plunger which releases a precisely measured quantity of a volatile flammable hydrocarbon liquid into the combustion cup.
Cranking the magneto handle produces a spark to ignite the fuel.
The flame heats a copper cylinder filled with wax. The wax expands, pushing a catch against a spring until it latches on the release mechanism of the bell.
When the fuel is exhausted, the flame goes out, the cylinder cools, and the wax contracts. The spring pushes the release mechanism of the bell, which rings when struck.
A gong version is also available.
The time can be adjusted by altering the setting of the graduated collar on the fuel pump plunger.