BACK-SIGHT
\bˈaksˈa͡ɪt], \bˈaksˈaɪt], \b_ˈa_k_s_ˈaɪ_t]\
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Back-sight. In levelling along a line, suppose the staff to be held at points A, B, C, D, etc., successively, the level is first placed between A and B, then between B and C, then between C and D, and so on; in these positions the surveyor looks back to A, B, C, etc., and forward to B, C, D, etc., and in each case reads the staff; the former readings are called back-sights, the latter fore-sights.
By Henry Percy Smith
Word of the day
tinctura quininae ammoniata
- A preparation made by dissolving quinin sulphate in alcohol [Br. Ph.].