'Burning Glases', and 'Burroughs's Machine', English, 1799.
© Science Museum / Science & Society Picture Library
Book plate engraved by J Pas, illustrating methods of creating fire by artificial means. 'Burning Glases' were devices incorporating lenses used in experiments by early chemists and alchemists. By placing lenses in the sun, and angling them towards the substance to be heated, a heat source was created which avoided the need to place an object directly in a fire. The use of burning glases was first noted in the writings of the Roman philosophers Seneca and Pliny the Elder, during the first century AD.