﻿ACROSS THE ^ENINSULA OF INDIA. 335 



perature was 58*, therefore 37* is the difference, or 

 fall of the thernionieter, since the precedi-ng day. 



The chain had contrafted 5S divisions on the mi- 

 crometer screw, eacli of which being equal -^ inches, 

 therefore the whole expansion of the chain was a^V 

 zz ,^27884 inches — and this divided by 37° gives 

 ,()07'2 1 inches, the expansion of the chain due to one 

 degree of the thermometer. 



December 13th, at half past six A.M. the mean 

 of tliree thermometers Mas 56** which was 39° de- 

 crease of tem.perature since the preceding day at one 

 o'clock P. jM. — The chain had contracted 60 di- 

 visions — therefore ^ divided, by 3^zz,007396 

 inches. 



At one P. IVI. the same day, the temperature was 

 97', and consequently the increase since morning 

 was 41°. The chain had expanded 63 divisions, 

 hence ^ divided by 4]^ gives-, 0073853 inches. 



December 15th. — At seven A. M. the tempera- 

 ture was 6i°, and at one P. M. 93° — and therefore 

 the increase since morning M-as 31°. Tlie chain 

 had expanded 46 divisions, therefore ~S^ divided by 

 3i° ~ ,00713 inches. 



December loth, at half past six A.M. the tem- 

 perature was 51°, i which v/as 41°, 8 below the pre- 

 ceding day at one o'clock P. KI. The chain had 

 contracted 59 divisions, which proceeding as before, 

 sri^'es ,006786 inches. 



Deceml^er 17tn, at half past six A. AI. the tem- 

 perature was 56°, and at one P. M. it was 9'i° — 

 whose diiference is 36°.- -The chain had 5S divi- 

 sions, which will give ,0076 J inches. 



Tjie mean of all these being ,007253 inches, I 

 J^ave therefore made the expansion of the chain due 

 to 1° of temperature above 6'2,° to be, 0073 inches. 



XL On 



