during the Quarter ending December 31, 1848. 191 



from erroneously assumed altitudes, and partly from the index 

 error of the instruments not having been determined. In most 

 cases the sums of their errors are small. 



The mean of the numbers in the second column, for those 

 places situated in Cornwall and Devonshire, is 47°*9 ; for those 

 places situated south of latitude 52°, including Chichester 

 and Hartwell, is 44'°'6 ; for those places situated between the 

 latitudes of 52° and 53°, including Saffron Walden and High- 

 field House, is 44-°'2 ; for those places situated between the 

 latitudes of 53° and 54°, including Liverpool and Whitehaven, 

 is 43°-3 ; and for Durham and Newcastle is 43°*0. These 

 values may be considered as those of the mean temperature of 

 the air for their parallels of latitude during the quarter ending 

 December 31, 1848. 



The average daily range of the temperature of the air in 

 Cornwall and Devonshire was 9°*6 ; at Liverpool and White- 

 haven was 6°*9; south of latitude 52° was ll°'6; between the 

 latitude of 52° and 54° was 9°*6; and at Durham and Newcastle 

 was 8°-9. 



The greatest mean daily ranges of the temperature of the air 

 took place at Greenwich, Hartwell, Latimer Rectory, and 

 Aylesbury respectively; and the least occurred at Whitehaven, 

 Guernsey, Torquay, Liverpool, and Truro respectively. 



The highest thermometer readings during the quarter were 

 76° at Hartwell and Leicester, 74° at Greenwich and Aylesbury. 

 The lowest thermometer reading was 20°'5 at Stonyhurst, 

 and readings about 21°occurred at several places. The extreme 

 range of temperature of the air during the quarter was there- 

 fore about 55°. 



The average quarterly range of the reading of the thermo- 

 meters in air in Cornwall and Devonshire was 37^*0 ; at Li- 

 verpool and Whitehaven was 36°'9 ; and the mean of the 

 numbers at all the remaining places is 48°*7. 



The mean temperature of the dew-point in Cornwall and 

 Devonshire was 43°-5 ; at all places south of 53° was 41°*6 ; 

 and it was 39°'6 at places north of 53°. 



The great mass of air has passed from the south-west in 

 all places except Exeter and Stonyhurst, at both of which 

 places it seems to have passed from the north. 



From the numbers in the tenth column the distribution of 

 clouds has been the same at all places, and such as to have 

 covered somewhat more than three-fifths of the whole sky. 



Rain has fallen on the greatest number of days during the 

 quarter at Highfield House, Stonyhurst, Derby, Leeds, Hel- 

 ston and Latimer, and the average number at those places 

 was 63. It fell on the least number of days at Aylesbury, 



