( 316 ) 

 TRIGONOMETRICAL SURVEYS. 



CHAPTER XV. 



Colonel Lambtovi's Surveys. 



Colonel Lambton appointed to make a Survey across the Peninsula — 

 Advantages possessed by him for this Task— Difficulties of a Trigo- 

 nometrical Survey — Colonel Lambton commences his Labours — Tri- 

 angles carried across the Peninsula — Continuation of the Survey — 

 Death of Colonel Lambton— Conclusion. 



About the year 1800, Colonel Lambton, then a major in 

 the king's service in India, a most intelligent officer, and 

 well versed in mathematical science, and particularly in the 

 means of applying it to the improvement of geography, 

 projected a survey across the peninsula of India, for the pur- 

 pose of determining the positions of the principal geographi- 

 cal points. By the success of the British arms, a district 

 of country had been acquired, which not only opened a free 

 communication with the Malabar coast, but, from its nature, 

 afforded the means of connecting that with the coast of Co- 

 romandel, by an uninterrupted series of triangles, and of 

 continuing that series to an almost indefinite extent in every 

 direction. He accordingly communicated his views to the 

 governor in council at Madras, and was by him appointed 

 to conduct that important service, with a liberality by which 

 alone it could be carried into execution. 



A new era had commenced in the practice of trigono- 

 metrical surveying, by the determination of the distance be- 

 tween the meridians of Paris and Greenwich. This was 

 begun by General Roy, in the year 1784, who then measured 

 a base of about five miles in length on Hounslow Heath 

 with a degree of scientific skill that had never before been 

 exceeded, and probably not then equalled. This was the 

 first of a series of operations. The labour was recommenced 

 in 1787, and carried on until completed, under the able 

 direction of the general, by a series of triangles extending 

 from Greenwich Observatory to Dover. A like series of 



