880 Dr BREWSTER on the Register of the Thermometer kept 



TABLE, showing the Deviations of the Mean Temperature of every similar Pair 

 of Hours from that of the Day. 



From this Table it follows, 



1. That of all the similar pair of hours, the mean of 4 h 



and 4 h approaches nearer to the mean temperature of 

 the day than any other pair. 



2. That the deviation of any pair is less than half a degree 



of Fahrenheit's scale. 



3. That the mean temperature of the pairs from 5 b to ll h 



are less than the mean temperature of the day ; and 

 that the mean temperature of the pairs from ll h to 5 h 

 exceed the mean temperature of the day *. 



* It now became interesting to compare with these results those deduced from 

 Mr COLDSTKEAM'S hourly register for one day in each month of the year, and also 

 those obtained by Professor DEWEY at Williamstown in North America. 



