﻿ACROSS THE PENINSULA OF INDIA; 553 



correflctl lor precession, nutation, and aberration, 

 for those days — and, in order to corre61; the error of 

 colHmation of the telescope, the instrument was 

 turned upon its vertical axis ou tlie Qlst, and the 

 zenitli distance taken on the opposite part of the arc. 

 — The Latitude determined by the observation made 

 on the If)th was 13°. GO'. 69,^5", and by that on the 

 20th, 13°. 00'. 5S,7'/'. N. On the Qlst, when the 

 se6tor was turned, the latitude was observed 13°. 00' 

 22, 6". which will tlierefore give the mean 1 3^ 00'. 40,(5* 

 N. From these it will appear that the error of colli- 

 mation was 1 S,095". 



The latitude of that station being obtained, and 

 also its distance from the south end of the base; — 

 from knowing the angle which that distance made 

 with the meridian, the distance on the meridian, 

 between the station, and the point where a line fall- 

 ing from the southern extremity M'ould cut it at right 

 angles, was easily had, and the difference of latitude 

 of the station and //tat point was computed, by al- 

 lowing 60191 fathoms to the degree in latitude ]3\ 

 — And that gave 12'- 54'. 6,6" for the latitude of the 

 point of intersection on the meridian of the station. 



The per{)endicuUir, falling from the south end of 

 the base on the meridian, was then converted into 

 miimtes and seconds, by allowing 60^57 fathoms 

 (b) for the degree on a great circle perpendicidar to 

 the meridian, and from that and the co-latitude of 

 the point of intersection, the latitude of the southern, 

 extremity of the bas3 was determined to be 12°. 



(h) These measures have been determined by computing on the el- 

 lipsoid given by Col. Williams and Capt. Mudge, as' resulting 

 from their measurement of a degree perpendicular to the meridian in la- 

 titude 50° 4 r N. and of a degree on the meridian in the fame latitude, 



as obtained from the measured arc between GreeftiL-ich and Paris, 



The ratio of the diameters of that ellipsoid is nearly as 230 to 23, 1,55. 

 — The principles on which thefe computations are founded, with the 

 most useful propositions relative to the ellipsoid, will be given 

 hereafter, when the figure of the earth becomes the subjed of investi- 

 gation. 



