This section is from the book "The Home Cyclopedia Of General Information", by Charles Morris. Also available from Amazon: Home Cyclopedia of Necessary Knowledge.
An electric arc-light of great candle-power, used with a parabolic projector which throws its rays for many miles. It is of great importance on a naval vessel, in enabling the captain to discover an approaching enemy at night. One shown at the Chicago Exposition of 1893 could be seen 85 miles away, and fine print was read by its light at 8 miles' distance.
 
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