Cross Staff & Back Staff Geocoin
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Owner:
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Daffy71
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Released:
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Saturday, June 9, 2012
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Origin:
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Texas, United States
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Recently Spotted:
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In the hands of brian's tigers.
This is not collectible.
Use TB44QQB to reference this item.
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I would like to visit places that help me look at the sky. All over the world I want to see the peaks of Mountains, the Darkness of the Desert, and have my picture taken with observatories.
Please don't keep me too long. I have to keep navigating the world!!!!!
Backstaff
The backstaff ' is a navigational instrument that was used to measure the altitude of a celestial body, in particular the sun or moon. When observing the sun, users kept the sun to their back (hence the name) and observed the shadow cast by the upper vane on a horizon vane. It was invented by the English navigator John Davis that described it in his book Seaman's Secrets in 1594
Cross Staff
The term Jacob's staff, also cross-staff, a ballastella, a fore-staff, or a balestilha, is used to refer to several things. This can lead to considerable confusion unless one clarifies the purpose for the object so named. The two most frequent uses are:
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in astronomy and navigation for a simple device to measure angles, later replaced by the more precise sextants;
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in surveying for a vertical rod that penetrates the ground and supports a compass or other instrument
Tracking History (1515.9mi) View Map