158 



MEASUREMENT OF AN ARC ON THE 



have been made with the same marked bamboo, 

 for ascertainino- the vakie of these divisions, and it 

 has been found that seven revolutions and 61,4 di- 

 visions are equal to ten minutes on the limb of the 

 semicircle, so that one division is equal to ,788 of 

 a second. 



TABLE 



Of eTperiments for determining the valuation of the 

 revolutions and divisions on the micrometer in the 

 eye-piece of the telescope. 



Hence one second will be equal to 1,269 divisions. 



One minute 75,72 ditto. 



Ten minutes 757,2 ditto. 



SECTION IV. 



Angles taken with the large theodelite between 

 27th September 1802, and 13th o^ April, 1803. 



AT THE NORTH END OF THE BASE. 



Between And 



South end of 7 tv-t *. *. *.• 

 , I \ Mount station, . 



the base, 3 



Perumbaiik hill, 

 Perumhauk hill, INIount station, . 



Observed Angles. 



91 09 04 



09 47 58,9 

 81 21 05,2 



