(hiring the Quarter ending September 30, 1848. 373 



may be considered as that of the pressure of dry air for England 

 during the quarter ending September 30, 1848. The differ- 

 ences between this number and the separate results contained 

 in the first column, show the probable sums of the errors of ob- 

 servation and reduction ; the latter arising partly from errone- 

 ously assumed altitudes, and partly in consequence of the index 

 error of the instruments not having been determined. In most 

 cases, however, the sums of these errors are small. 



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

 places situated in the counties of Cornwall and Devonshire, is 

 58 0, 1 ; for those places situated south of latitude 52°, including 

 Chichester and Hartwell, is 57°*8 ; for those places situated 

 between the latitudes of 52° and 53°, including Saffron Walden 

 and Highfield House, was 56 0, 8 ; for those places situated 

 between the latitudes of 53° and 54°, including Liverpool and 

 Whitehaven, but not Stonyhurst, whose mean temperature, 

 from its greater elevation, is lower than that due to its latitude 

 alone, was 56 0, 2; and for Durham and Newcastle was 55°*8. 

 This value, however, is somewhat too high for the former 

 place and too low for the latter, on account of the difference 

 of elevation of these places. These values may be considered 

 as those of the mean temperature of the air for these different 

 parallels of latitude during the quarter ending September 30, 

 1848. 



The average daily range of the temperature of the air in 

 Cornwall and Devonshire was 14°*2; at Liverpool and White- 

 haven was 10°*2; south of latitude 52° was 19°-5; between the 

 latitudes of 52° and 53° was 15 0, 8 ; between the latitudes of 53° 

 and 54° was 15 0, 9; and of Durham and Newcastle was 14°*4. 



The greatest mean daily ranges of the temperature of the air 

 took place at Hartwell, Latimer, Aylesbury and Leicester 

 respectively; and the least occurred at Liverpool, Whitehaven, 

 Torquay and Truro respectively. 



The highest thermometer readings in air during the quarter 

 were 95° at Leicester, 90° at Wakefield, and 89° at Hartwell ; 

 but it seems highly probable that these readings are greater 

 than the temperature of the air really reached. The reading 

 88° seems to be confirmed, and this value may be considered 

 as the highest during the quarter. The lowest values of the 

 thermometer readings in air were 29° at Hartwell, 31° at La- 

 timer and Cardington. The extreme range of temperature 

 of the air during the quarter was therefore about 59°. 



The average quarterly range of the reading of the thermo- 

 meter in Cornwall and Devonshire was 33°*2 ; at Liverpool 

 and Whitehaven was 32 0, 5; and the mean of the numbers at 

 all the other places is 49 0, 2. The highest and lowest readings 



