Current Use
Large burning lens are sometimes made as Fresnel lenses, similar to lighthouse lenses, including for use in solar furnaces. Solar furnaces are used in industry to produce extremely high temperatures without the need for fuel or large supplies of electricity. They sometimes employ a large parabolic array of mirrors (some facilities are several stories high) to focus light to a high intensity.
The Olympic torch that is carried around the host country of the Olympic games is lit by means of a burning glass. The ceremony is organized at the site of ancient Olympia in Greece. The first use of this torch was for the 1936 Summer Olympics in Berlin.
Read more about this topic: Burning Glass
Famous quotes containing the word current:
“Without the Empire we should be tossed like a cork in the cross current of world politics. It is at once our sword and our shield.”
—William Morris Hughes (1864–1952)
“Reputation runs behind the current state of affairs.”
—Mason Cooley (b. 1927)