70 CLIMATE. 



for 24 mon'ths in 3 years, 23-018. This is probably near 

 the truth, and Dr. Dalmahoy, in his calculations to deter- 

 mine the height of Ootacamuud above the level of the sea, 

 assumes it to be 23-005. 



Subjoined are the results in a tabular form : 



Mean height of the barometer, 23 018 



Greatest range, "700 



Mean amiual range; '495 



Probable mean daily range, "040 



Greatest daily range, '060 



Temperature. The observations from which the subr 

 joined conclusions are drawn, are the fruit of pretty close 

 and continued attention to a number of very good instru- 

 ments, placed in a situation to be little, if at all, affected by 

 extraneous circumstances, so that they may be depended on 

 as tolerably accurate, particularly for the last nine months, 

 through which they are consecutive. 



There are several methods of estimating the mean tem- 

 perature of a place elevated above the level of the sea. 

 One is, by taking the temperature of copious springs near 

 their sources. Another, by supposing the heat to decrease 

 uniformly at a certain rate, ascending from the level of the 

 sea ; and a third, by taking the mean of the observed tempera- 

 ture. This last is of course by much the most accurate, 

 but we shall find that it agrees in a remarkable manner 

 with the other two. 



According to the calculation already given, in discussing 

 the effects of elevation on temperature, the mean tempera- 

 ture of Ootacamund should be 52°-28. 



There is some discrepancy of opinion as to the correct 

 method of ascertaining the mean observed temperature. The 

 author of the able article. Meteorology, in the Edinburgh 



