30 Dr Brewster on the Register of the Thermometer kept 



Difference between the Mean Temperature of each Hour and that nj 

 the Day, for 1824 and 1825. 



From this table, it appears, that the mean annual tempera- 

 ture of any hour of the day never differs more than S°\ from 

 the mean temperature of the day for the whole year. 



In order to obtain the mean temperature of the year from 

 a register which contains observations made once every day, 

 we have only to correct the mean temperature which the 

 register gives, by applying, according to its sign, the correc- 

 tion opposite to the given hour. In place of taking the mean 

 of the two years, it might be preferable to take the results for 

 1824, in cold years, and those for 1825, in warm years. 



IV. On the average Daily Range for each Month. 



In a climate so variable as that of Scotland, the daily range 

 of the thermometer is often very great, both in winter and in 

 summer ; but the average daily range which we propose now 

 to notice, is the measure of the daily change of temperature 

 for each month, and will, of course, bear some relation to the 

 sun's declination, as appears from the following table. 



Mean of 1824 & 1825. Mean of 1824 & 1825. 



