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| | USNO Millennium Program: History of the USNO Time Ball |
 | | As an institution that owed its founding to the necessity for accurate time in the form of the marine chronometer, time as determined by astronomical observation was at the very heart of its mission. |
 | | A number of balls and a variety of methods for dropping, including controlled lowering, dropping onto the dome, and throwing by hand were probably used in the early period, until an electromagnetic relay released the raised ball. |
 | | By 1867 time was telegraphed "at noon, by the different lines of wires, to the northward, eastward, and westward, and as far southward as Texas." By 1869 Western Union distributed signals "which serve to regulate the clocks of nearly all the railroads in the southern States." |
| www.usno.navy.mil /tball.html (1174 words) |
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