1870.] The Surveys of India, 449 



and Ireland was projected. Perhaps a more important survey, in 

 some respects, than the British one was that undertaken by the 

 French nation at the period of the Kevolution. About that date 

 the philosophers of France undertook to introduce a great reforma- 

 tion in regard to all those habits and usages of men which have 

 reference to numbers, and everything — lengths, areas, moneys, 

 weights, periods of time, arcs of circles — was to be numbered by 

 tens, hundreds, thousands, &c. The question then came to be, 

 What should be adopted as the basis of this standard, which was 

 designed not only for France, but for the world? This ques- 

 tion having been brought to the attention of the Constituent 

 Assembly, it was proposed by M. de Talleyrand, and decreed ac- 

 cordingly, that the Parliament of England should be requested to 

 concur with the National Assembly in fixing a natural unit of 

 weights and measures ; that under the auspices of the two nations, 

 an equal number of Commissioners from the Academy of Sciences 

 and the Royal Society of London might unite in order to determine 

 the length of the pendulum which vibrates seconds in the latitude 

 of 45° (as proposed originally by Huyghens), or in any other lati- 

 tude that might be thought preferable, and to deduce from them an 

 invariable standard of measures and of weights. The Commission 

 named by the Academy had under their consideration three different 

 units, namely, the length of the pendulum, the quadrant of the 

 meridian, and the quadrant of the equator. The length of a quad- 

 rant of the meridian having been determined on, the measurement 

 of an arc was entrusted to MM. Mechain and De Lambre, who 

 began their labours in 1792, and thus commenced the trigonome- 

 trical survey of France. 



The origin of the Great Trigonometrical Survey of India was not 

 unlike that of the first Scottish Survey. After the successful termi- 

 nation of the war with Tippoo Saib, at the close of the last century, 

 Captain Lambton (who had previously served as a surveyor in 

 America, and who joined Her Majesty's 33rd Regiment at Calcutta 

 in the year 1797) brought forward his plan of a geographical 

 survey of part of the territory that had been conquered, and he 

 proposed to throw a series of triangles across from Madras to the 

 opposite coast, for the purpose of determining the breadth of the 

 peninsula in that latitude, and of fixing the latitudes and longitudes 

 of a great many important places, which were believed to be very 

 erroneously determined in the survey previously executed by Colonel 

 MacKenzie. Captain Lambton first submitted his plan to Colonel 

 Wellesley, in whose regiment he had formerly served, who at once 

 sent up the proposal to Government supported by his strong recom- 

 mendation. Lord Clive was at that time Governor of Madras, and 

 warmly approved of the undertaking, and it was accordingly sanc- 

 tioned by Government. 



