24 Dr Brewster on the Register of' the Thermometer kept 

 The following are the Mean Monthly Results for 1824, and 1825. 



The following Table shows the Mean Temperature of each hour of the day 

 for 1824, 1825, each result being the mean of 730 observations. 



Having given, in the preceding tables, the principal nu- 

 merical results of the hourly Register for 1824 and 1825, we 

 shall now proceed to consider some of the most important 

 conclusions which may be deduced from them. 



I. On the Form and Character of the Annual and Monthly 

 Daily Curve, or the Daily Progression of Temperature. 



The daily curve for 1824 is projected in Plate V. Fig. 27. 

 of last Volume, from the numbers in the last column of 

 Table II., and forms the lowest curve. The point of the 

 curve for each of the 24 hours is the mean of 365 observa- 

 tions. The temperature is lowest between 4 and 5 o'clock 

 in the morning ; it then increases with great regularity till 

 3 o'clock in the afternoon, when it descends till it reaches its 

 minimum at 5 o'clock in the morning. The period during 

 which it performs its ascending motion is 9 h 40', and the pe- 



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