Burning Glass

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:

    mourn

    The majesty and burning of the child’s death.
    I shall not murder
    The mankind of her going with a grave truth
    Nor blaspheme down the stations of the breath
    Dylan Thomas (1914–1953)

    A sudden violent jolt of it has been known to stop the victim’s watch, snap his suspenders and crack his glass eye right across.
    Irvin S. Cobb (1876–1944)