'The energy driving the Electric Clock is obtained from a zinc carbon couple buried three to four deep and one foot apart in moist soil. A soil with some drainage is preferred, but not too sandy as it is necessary to keep it moist...This Earth Battery provides a potential of approximately 1 volt at the clock terminals. Carbon was used for the electrode...customarily obtained from the local Gas Works in the form of retort coke.'Dr F.G. Alan Shenton, 'The Earth Driven Clock', Antiquarian Horology, December 1972, p.66.
P.A. Bentley took out his first patent (19044) on 13 August 1910. In 1912 he opened his Earth Driven Clock Company factory in Leicester, where the company continued making clocks until September 1914, by which time there were twelve employees. After this it expanded to help the work effort. Cases for Bentley clocks were made by Thomas Jones, Cabinet Maker and Pattern Maker, 61 Bardolph Street, Leicester (the Leicester Cabinet Company after 1909). The clocks were usually sold through Harrods in London but also through a furniture store in Leicester. They were sold around the world - a representative of the company travelling on business was among the victims of the 1912 Titanic disaster.