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A utility pole, commonly referred to as a transmission pole, telephone pole, telecommunication pole, power pole, hydro pole, telegraph pole, or telegraph post, is a column or post used to support overhead power lines and various other public utilities, such as electrical cable, fiber optic cable, and related equipment such as transformers and ...
The rod, perch, or pole (sometimes also lug) is a surveyor's tool [1] and unit of length of various historical definitions. In British imperial and US customary units , it is defined as 16 + 1 ⁄ 2 feet , equal to exactly 1 ⁄ 320 of a mile , or 5 + 1 ⁄ 2 yards (a quarter of a surveyor's chain ), and is exactly 5.0292 meters.
It varied in size at various times and places; the Spanish unit was set at about 835.905 mm (32.91 in) in 1801. [citation needed] In Argentina, the vara measured about 866 mm (34.1 in), and typical urban lots are 8.66 m (28.41 ft) wide (10 Argentine varas). At some time a value of 33 inches (838.2 mm) was adopted in California.
Date nails are also found on utility poles, sometimes in conjunction with a nail showing the height of the pole in feet. The types of nails may have distinguishing characteristics, such as the date nail having raised digits and the "height nail" having incised digits. The pole height will be a multiple of five (e.g., "35" or "40"). [5]
Cooke and Wheatstone's five-needle telegraph from 1837 Morse telegraph Hughes telegraph, an early (1855) teleprinter built by Siemens and Halske. Electrical telegraphy is a point-to-point text messaging system, primarily used from the 1840s until the late 20th century.
[1] [2] [3] Chappe used the term télégraphe to describe the mechanism he had invented – that is the origin of the English word "telegraph". [4] Lines of relay towers with a semaphore rig at the top were built within line of sight of each other, at separations of 5–20 miles (8–32 km).
The first experiments in radio communication were conducted by Guglielmo Marconi beginning in 1894. In 1895–1896 he invented the vertical monopole or Marconi antenna, which was initially a wire suspended from a tall wooden pole.
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