A burning glass or burning lens is a large convex lens that can concentrate the sun's rays onto a small area, heating up the area and thus resulting in ignition of the exposed surface. Burning mirrors achieve a similar effect by using reflecting surfaces to focus the light. They were used in 18th-century chemical studies for burning materials in closed glass vessels where the products of combustion could be trapped for analysis. The burning glass was a useful contrivance in the days before electrical ignition was easily achieved.
Read more about Burning Glass: History, Current Use
Famous quotes containing the words burning and/or glass:
“angelheaded hipsters burning for the ancient heavenly connection to
the starry dynamo in the machinery of night,”
—Allen Ginsberg (b. 1926)
“When God at first made man,
Having a glass of blessings standing by,
“Let us,” said He, “pour on him all we can:
Let the world’s riches, which dispersed lie,
Contract into a span.””
—George Herbert (1593–1633)