V. 



An Account of the Measurement of a?i Arc on the 

 Meridian on ///f Coast o/"Coromandel, athi 

 the Length of a Degree deduced therefrom hf th^ 

 Latitude 12" 32'. 



By Brigade Major WILLIAM LAMBTON. 



In a former Paper which I had the honour to com-^ 

 municate to the Asiatick Society, 1 gave a short 

 sketch of an intended pL^n for establishing a series 

 of connecting points commencing from the CVo- 

 mandel Coast, and extending across the Peninsula ; 

 but that Paper was only meant to convey a general 

 idea of the principles on which the work was to \)^. 

 conducted ; a more circumstantial and scientific ac- 

 count, it was thought, would be more to the pur- 

 pose, when I had the means of putting the plan in exe- 

 cution, and detailing the particulars. Since that time 

 I have received a most complete apparatus, which 

 has enabled me to proceed on the scale I originally 

 proposed, and what is herp offered is the beginning 

 of that work, being the nieasurement of an arc on 

 the meridian, from which is deduced the length of a 

 degree for the latitude 12® 2>'l' which is nearly the 

 middle of the arc. 



The triangles here mentioned are those only, Tro n 

 vvhich the arc is obtained, and the base line, the 

 foundation to the whole, is a measured line near the 

 ^a Coast, an account of which is here subjoined. 



