*yo SCIENTIFIC APPARATUS. 



the part of the English officers of that day to explore its sources 

 and the mighty chain of the Himalaya, and to measure some of 

 the highest peaks. In 1800 Lieutenant Wood executed a series 

 of maps of the course of the Ganges from Hurdwar to Allaha- 

 bad (10); and in 1808 Captain Webb continued the work from 

 Hurdwar up to near the source of the Ganges at Gangotri (n). 

 Route maps were also made, by officers accompanying armies or 

 missions, in Oudh and Rohilcund, in Nepal and Kumaon, in 

 Bundelcund and Bhopal, while a second series of maps of Bengal 

 resulted from Dr. Buchan Hamilton's statistical survey between 

 1807 and 1814. 



As these special maps accumulated the want of a new general 

 map of India soon began to be felt, to supersede those of D'An- 

 ville and Rennell. In 1816, Aaron Arrowsmith published his 

 Map of India in nine sheets, on a scale of sixteen miles to an inch, 

 which was the last great general map based on route surveys (12). 

 His subsequent Atlas of South India, published in 1822, was 

 based upon the trigonometrical surveys of Colonel Lamb ton, filled 

 in by the officers of the Madras Institute. It was in eighteen 

 sheets, extending from Cape Comorin to the River Kistna (13). 



By this time the Great Trigonometrical Survey of India had 

 been in progress for twenty years, and the East India Company 

 determined upon the publication of the Indian Atlas, a gigantic 

 undertaking, which is still in progress. The work was entrusted 

 to Mr. John Walker, the eminent engraver, who combined the 

 various documents sent home by the surveyors in India, prepared 

 the sheets for publication, engraved them on copper, and issued 

 them. The Atlas was designed to occupy 177 sheets, on a conical 

 projection, and a scale of four miles to the inch. This scheme 

 embraces the space from Karachi to Singapore, and includes 

 Ceylon. The brass scale, from which all measurements for the 

 copper-plates of the Atlas were taken, is still preserved. The first 

 published sheets were those for which the Madras Surveys fur- 

 nished the materials, and appeared in 1827 (14). Then followed 



