6l6 



PHILOSOPHICAL TRANSACTIONS. [aNNO 1775. 



The mean of all 21° 26' 



Error of instrument — 10 



Correct variation 21 16 west. 



XVI. An Abridged Stale of the Weather at London in the Year 1774, col- 

 lected from the Meteorological Journal of the R. S. By S. Horsley, LL.D., 

 Sec. R. S. p. 167. 



Though the practice of keeping meteorological journals is, of late years, be- 

 come very general, no information of any importance has yet been derived from 

 it. The reason of which perhaps may be, that after great pains and attention 

 bestowed in registering particulars, as they occur, with a scrupulous minuteness, 

 observers have not taken the trouble to form, at proper intervals of time, com- 

 pendious abstracts of their records, exhibiting the general result of their obser- 

 vations in each distinct branch of meteorology. The following tables are given 

 as an example of the method that may be taken in future to remedy this neglect. 

 With the general state of the barometer and thermometer, already given at the 

 end of the meteorological journal, they form a history of the weather at London 

 during the last year. If the example were to be followed, in different parts of 

 the kingdom, we might in time be furnished with an experimental history of the 

 weather of our island. 



TABLE I. 



An abridged View of the Winds at London, in 1774. 



Compiled from the Meteorological Journal of the Royal Society. 



( Five half days omitted in 

 l the Journal. 



{Half a day missed in the 

 Journal. 



{A half day missed in the 

 Journal. 



This table shows the number of days that each wind blew in each month, 

 dividing the compass only into 8 points, and reckoning all the winds between n. 

 and w., N. w.; all between s. and e., s. e.; all between n, and e., n. e.; and all 



