On the Meteorology of England and the South of Scotland, 373 



to zero, and we shall obtain two systems of values of/, g 9 

 wherefrom we derive 



l l x + m l y=± s/aj\ + bg x . P 



l 2 x -j-m 2 y=± Vaf 2 -f bg 2 . P, 



from which x and y may be determined. 



26 Lincoln's-Inn-Fields, 

 August 28, 1850. 



XLIX. On the Meteorology of England and the South of Scot- 

 land during the Quarter ending September 30, 1850. By 

 James Glaisher, Esq., F.R.S., Hon. Sec. of the British 

 Meteorological Society, fyc* 



THE mean daily temperature of the air was below its ave- 

 rage value till July 13; the mean defect, was 2°*2. From 

 July 12 to the 24th, the period was warm ; the average excess 

 of temperature was 4< 0, 8. From July 25 to August 3, the 

 temperature was below the average; its mean deficiency was 1°. 

 From August 4 to August 18, it was above the average ; the 

 mean excess was 2° ; this was followed by a long period of fine, 

 clear, dry, but cold weather. The average deficiency of tem- 

 perature between August 19 and September 17 was 3 C \5 ; and 

 after September 18, the daily temperatures were slightly above 

 their average values. Snow fell on Ben- Lomond on August 23. 



The mean temperature of the air at Greenwich for the three 

 months ending August, constituting the three summer months, 

 was 6i 0, l, being l°*2 above the average of the preceding 

 seventy-nine summers. 



For the month of July was 62 0, 2, exceeding that of the ave- 

 rage of seventy-nine years by 0°*9,and of nine years by 0°*7. 



For the month of August was 60 o, 2, being o, 3 less than 

 the average of seventy-nine years, and 0, 9 less than that of the 

 preceding nine years. 



For the month of September was 56°'4?, exceeding the ave- 

 rage from seventy-nine years by 0°'l, and less than that of 

 the preceding nine years by 0°*7. 



The mean for the quarter was 59°*6, exceeding that of the 

 average of seventy-nine summer quarters by 0°*2, and less 

 than that of the nine preceding years by o, 3. 



The mean temperature of evaporation at Greenwich — 



For the month of July was 58°*6 ; for August was 56°'6 ; 

 and for June was 52°*9. These values are o, 9 greater, o, 2 

 greater, and 1°'6 less than those of the averages of the same 

 months in the preceding nine years. 



* Communicated by the Author. 



