120 Approximate Values of the Radii of Curvature, fyc. [Aug. 

 — , to find the length of a meridional degree at the equator. 



By Art. 5, m = M (1 - 3 e s*), where M = 60491-46, e = 

 ig, and a = sin. 13° 34' 44". 



Log. 3 = 0-4771213 



W. — = 3-5086383 



O 310 



Sum = 3-9867596 



Half sum = 2-9928798 



Log. sin. 13° 34' 44" = 1-3706684 



Sum considered as a sin = 2*3635482 



Cos. even therewith = J-9998842 



Its double = 1-9997684 



Log. 60491-46 = 4-7816940 



Sum of two last = 4-7814624 



Which corresponds to the 60459*2 fathoms, the required length 

 of a meridional degree at the equator. 



Example 4. — Given the compression — and the length of a 



meridional degree at the equator 60459-2 fathoms, to find the 

 length of a degree perpendicular to the meridian at the equator. 



By Art. 6,p = m (^) = 60459-2 x g. 



Log. 60459*2 = 4-7814624 



Log. 313 = 2-4955443 



Log. 311 ar. com = 3-5072396 



Log. 60848 = 4-7842463 



Therefore 60848 fathoms, is the length of a degree perpendicular 

 to the meridian at the equator. 



Otherwise, by retaining e 4 , we have at Art. 4p = ™ a = 



tn (310)* _ 96100 m 

 (309) 2 ~" 95481 



Log. m = 4-7814624 



Log. 96100 = 4-9827234 



Log. 95481 ar. com = 5-0200830 



Log. 60851-1 = 4-7842688 



Which differs from the preceding value by 3*1 fathoms. 



