burning glass

American  

noun

1. a converging lens used to produce heat or ignite substances by focusing the sun's rays.

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burning glass British  

noun

1. a convex lens for concentrating the sun's rays into a small area to produce heat or fire

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Etymology

Origin of burning glass

First recorded in 1560–70

Example Sentences

See Examples For:

burning glass

He and I know to move around them by sheer memory; the burning glass promises to singe the skin if touched.

From The Guardian ● Apr. 17, 2018

Many historians, in fact, have dismissed the story of the burning glass as a myth.

From Time Magazine Archive

The combination acts as a gigantic burning glass which can melt 130 Ibs. of iron in an hour.

From Time Magazine Archive

Secondly, was his 'into battle' period, when his superb rhetoric and unflinching courage focused like a burning glass the latent will to win of heroic, freedom-loving men the world over, when all seemed lost.

From Time Magazine Archive

The action is that of a burning glass, and extends throughout the leaf-tissues.

From Disease in Plants by H. Marshall Ward