370 The Meteorology of Whitehaven. 



The mean temperature of the past summer is 1.786 under the average, 

 and the thermometer attained to 70° on six days only. 



Every month, from January to September inclusive (April excepted), 

 was below the mean average temperature. The mean value of the dif- 

 ference in the nine months amounted to 2°.264, and in some of the 

 months it extended to 4°.5, and even to 5 degrees. 



The highest point which the thermometer reached this year was 72°.5 

 on the 19th of July, and the lowest point to which it fell was 16°.o, on 

 the nights between the 30th and the olsfc Jan., and 31st Jan. and 1st Feb. 



We have frequently had occasion to allude to the high mean annual 

 temperature of Whitehaven, and especially to the very limited range 

 of the thermometer in the winter season, as compared with inland 

 towns, and many localities in the south of England. During severe 

 frosts, the thermometer at Wigton and Carlisle is frequently 15 or 20 

 degrees, and in the south, as much as 30 or 35 degrees, lower than with 

 us. Even at Paris, Lyons, and other places in France, the temperature 

 in winter is often lower than at Whitehaven. Thus, on the 7th instant 

 (Jan. 1846), the thermometer at Lyons marked 9^ centigrade (below the 

 freezing pointj, equal to 17° of Fahrenheit ; at Whitehaven, the thermo- 

 meter has not been lower than 28''.5 during the present season, and on 

 the night in question, the lowest point to which it fell was 36% or 19° 

 higher than at Lyons. 



On the whole, we believe there are very few localities in Great Britain 

 which are favoured with so mild and genial an atmosphere, or are less 

 subject to those sudden vicissitudes of temperature, which render the 

 climate of England so trying to those subject to catarrhal diseases, bron- 

 chitis, or other more alarming affections of the lungs and air-passages. 



Barometer. — The mean atmospheric pressure is rather less than it has 

 been for several years past. The mean at 9 a.m. is 29.701, at 3 p.m. 

 29.693, and at 9 p.m. 29.700, exhibiting the horary oscillation of the pres- 

 sure caused by the variation of the sun's altitude, and, consequently, of 

 temperature during the 24 hours. The mean pressure at 9 or 10 p.m., 

 is almost invariably greater than at 9 a.m. ; this year, however, the re- 

 verse is the case. The highest pressure (30.27) occurred on the 16th 

 and I7th April, and on the 23d October ; the lowest on the night of the 

 19th November; the annual range is consequently 1.78. 



Hygrometer. — The mean of the dew-point, or point of saturation, is 

 42.56, being 5°. 18 below the temperature of the air. In 1844, the com- 

 plement of the dew-point was 5°.^Qi consequently, there has been rather 

 more moisture in the atmosphere than in the previous year ; but the mean 

 value of the difl'erence only amounts to .48, or less than half a degree. 

 And as the nearer the temperature of the air approaches to the point of 

 saturation, the less the evaporation, we find accordingly, that the mean 

 evaporation force, which in 1844 was 5.66 grains per hour, is this year 

 only 5.18 grains per hour. 



The driest days of the past year were the 30th and 31st of May, when 

 the complement of the dew-point was 19° and 21'' respectively, and the 

 evaporation force amounted to 1.54 grains, and 1.12 grains per minute. 



Terrestrial Radiation. — The direct effect of terrestrial radiant heat was 

 determined by means of delicate naked thermometers placed in wicker 

 baskets containing tow, cotton, wool, «&c., in order to obtain the radia- 

 tion to the best possible effect. The instruments were exposed on a 

 grass-plot, under a clear and cloudless sky, and the minimum tempera- 

 ture compared with that of a Six's thermometer (protected from radia- 



