earth's compression at the poles. 325 



"We have already described two of these, viz. one extending 

 from Punnae, lat. 8° 9' 38", to Putchapoliam, in lat. 10° 

 59' 49", and another extending from Putchapoliam to Nam- 

 thabad, in lat. 15° 6'. He had afterward the good fortune 

 to get another section extending from Namthabad to Dau- 

 mergidda, in the nizam's dominions, which, being in lat. 18° 

 3' 24", gives an addition of 2° 57' 23", making on the whole 

 an arc of 9° 53' 45" in amplitude, — an extent of upwards 

 of 680 miles, — the longest single arc that had ever been 

 measured on the surface of the globe at the time it was ac- 

 complished. The number of base lines measured were five. 

 He had now got the measured length of a degree in three 

 different parallels, viz. — 



FithoDis. Mid. lat 



60472.83 9034' 44" 



60487.56 13 2 55 



60512.78 16 34 32 



From these, compared with the length of degrees meas- 

 ured in England, Sweden, and France, he obtained various 

 fractions for the earth's compression at the poles, and taking 

 a mean among them, at last came to the conclusion that 

 the compression was ^j-^. The rei^ainder of the details in 

 his abstract of his operations is highly interesting to mathe- 

 maticians, but hardly to general readers. , 



Again, in the Philosophical Transactions for the year 

 1823, Colonel Lambton has applied to his measured me- 

 ridional arc the corrections necessary to change his former 

 measures to the parliamentary standard measure. The 

 differences are too trifling to require notice in the general 

 view which we have attempted to give of the exertions of 

 this indefatigable labourer in the field of science. He con- 

 tinued the survey beyond this period ; and we add with re- 

 gret that he died in January, 1830. 



We have selected the labour of Colonel Lambton as a 

 proof of the intelligence with which the present ruler.s of 

 India have applied their power and their ample means to 

 the promotion of geographical knowledge. Science suffered 

 a great loss by the death of that meritorious officer ; but 

 we add with satisfaction, that he has had successors who, in 

 his lifetime, had prosecuted similar views. In the fourteenth 

 volume of the Asiatic Researches, we have a journal of a 

 survey to the heads of the rivers Ganges and Jumna, by 

 Vol. hi.— E e 



