66 \ COMPARISON BETWEEN THE 



THE MEAN HEIGHT AND MEAN RANGE OF THE BARO- 

 METER FOR THE YEAR. 



Mean height. Mean range. 



London 29.954 1.127 



Malvern 29.362 1.155 



Mr. Daniell, from an average of three years observations, makes 

 the mean height of the barometer in London 29.881. The mean of 

 trventi/ yearsy deduced by Mr. Howard, is 29.865. 



In the second volume of " The Analysts* p. 218, it is stated that, 

 in consequence of the elevation of Great Malvern, it is necessary to 

 add about .570 in. to the barometrical heights observed there. If we 

 do this to the mean annual height just stated, it will appear that the 

 result deduced by the foregoing comparison, does not vary much 

 from that of Mr. Daniell, nor from Howard's. 



DEW POINT. 



1 . — The mean dew point in London during the summer, is about 

 2J° higher than the mean dew point, during the same sea- 

 son, at Malvern. 



2. — The same observation applies to the autumnal quarter : — an 

 effect, doubtless, owing to the elevation of the latter locality, 

 and to its distance from any large expanse of water. 



3. — During the winter months the mean dew point is f a degree 

 higher in Malvern than in London. 



4. — In spring the mean dew point is the same in both places. 



MEAN DEW POINT FOR THE YEAR, 



AT 9 A. M. 



London 46.4 



Malvern 45.2 



From a mean of the daily maxima and minima, Mr. Daniel! finds 

 the mean annual dew point at London 44.5°. It will be borne in 

 mind that the annual mean just stated in this communication, is 

 derived from dailv observations at 9 a. m. 



