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Jesse Ramsden

Dividing engine




 Ramsden's divider eliminated the risk of human error and made it feasible to inscribe lines accurate to a second of an arc. 

Sextant

Sextant has polished brass 120° scale (-2° to 136°) with 20’ divisions and brass vernier (30”), 


Theodolite



Esri

Mapping the nation, Triangulation of great Britain 

Anglo-french survey

Reference

FSU

Sciencemuseumgroup 

Smithsonian 

Joseph Whitworth:



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劣質洗衣機入水喉

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ES8311 and ES8388 codec IC

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sharpstar 150mm f/2.8 hyperbolic astrograph

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