Mr. J. Glaislier's Remarks on the Weather. 131 



For the month of December was 42°-8, which is 2°"3 above 

 that of 1841, 2°-2 below that of 1842, 1°-1 below that of 1843, 

 9^-8 above that of 1844, 1°-1 above that of 1845, and 9°-9 above 

 that of 1 846 ; or it is 3°*3 above that of the average for these 

 six years. 



The mean value for the quarter was 47°'5; that for 1841 

 was 44°-0; for 1842 was 44°'4 ; for 1843 was 45^^-2; for 1844 

 was 42°-2; for 1845 was 45°-9 ; and for 1846 was 43°-l; so 

 that the excess for this quarter above the corresponding quar- 

 ter in the six preceding years are 3^*5, 3°"1, 2°"3, 5°"3, l°'6, 

 and 4°*4 respectively; or it is 3°*4 above the average for these 

 six years. This difference is very large indeed, considering 

 that it extends over so long a period of time as one-fourth 

 part of a year. 



The mean temperature of evaporation at Greenwich — 



For the month of October was 50°-9, which is 3'^*6 above 

 that for the preceding six years. 



For the month of November was 45°'6, which is 2°-6 above 

 that for the preceding six years. 



For the month of December was 41°'6, which is 3''-3 above 

 that for the preceding six years. 



The mean value tor the quarter was 46^'0, which is 3°-2 

 above that for the six preceding years. 



The juean temperature of the dew-poiiit at Greenwich — 



For the month of October was 49°-l, which is 4°-0, 6°-?, 

 4°'4, 3°-l, 2°-6, and l°-9 above that for the years 1841 to 1846 

 respectively ; or it is 3"- 7 above the average for these years. 



For the month of November was 44"'l, which is 4°-3, 3°-7, 

 3°-2, 2°-2, l°-3, and l°-0 above that for the years 1841 to 1846 

 respectively ; or it is 2°-6 above the average for these years. 



For the month of December was 39'^-8, which is 4 -6 above 

 that for 1841, 3°-4 beUm that for 1842, 2''-2 below that for 

 1843, 9°-8 above that for 1844, 2'^-2 above that for 1845, and 

 10°'4 above that for 18i6; or it is 3''-6 above the average for 

 these years. 



The mean value for the quarter was 44°-3, which is 3°*3 

 above that for the six preceding years. 



The mean weight of water in a cubic foot of air for the quar- 

 ter was 3-2 grains, which is 0'4 grain above that for the pre- 

 ceding six years. 



The additional weight of water required to saturate a cubic 

 foot of air was 04 grain ; the average for the preceding six 

 years was 0*3 grain. 



The mean degree ofhutnidily of the atmosphere for the quarter 

 was 0-900, which is the same as that for the six pieceding years. 



'I'he mean clastic force of vapour for the quarter was 0*310 

 K 2 ' 



