The Maritime History of the Great Lakes
Detroit Free Press (Detroit, MI), 12 Jul 1866


Description
Full Text
DISTANCES AT WHICH LIGHTS CAN BE SEEN.

The following are the approximate distances ay which lights on the lakes can be ssen, the eye and the light both being at the same elevation above the surface of the sea. The spheroidal form of the earth is the interruption to the line of sight at a long distance. At five feet elevation of the eye and the object, a light is seen nearly three miles; at 20 feet elevation, nearly six miles; at 40 feet, nearly eight and a half miles; at 60 feet over ten miles; at 80 feet, nearly twelve miles; at 100 feet, over thirteen miles; at 140 feet, nearly seventeen miles, at 200 feet, nearly nineteen miles; at 300 feet, nearly twenty-three miles; at 500 feet, over twenty-nine and a half miles; at 1,000 feet, nearly forty-two miles.


Media Type:
Text
Newspaper
Item Type:
Clippings
Date of Original:
12 Jul 1866
Local identifier:
GLN.1966
Language of Item:
English
Donor:
Dave Swayze
Copyright Statement:
Public domain: Copyright has expired according to the applicable Canadian or American laws. No restrictions on use.
Contact
Maritime History of the Great Lakes
Email
WWW address
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Detroit Free Press (Detroit, MI), 12 Jul 1866