The Wind and its Direction. 125 



THE WIND AND ITS DIEECTION. 



BY E. J. LOWE, E.K.A.S., F.L.S., ETC. 



The registration of the changes of the wind as marked down 

 by the " Atmospheric Recorder/' is known to bnt few persons. 

 Only one instrument is at work, and this is at the Beeston 

 Observatory. The value of the instrument is so great that it 

 deserves to be described. 



The late Mr. Henry Lawson, F.R.S., of Bath, and the late 

 Mr. George Dollond, were the inventors and constructors of this 

 machine. 



Sir John Herschel had published a request to all observers 

 to make constant observations for twenty-four hours on four 

 specified days in each year ; and Mr. Lawson being an inge- 

 nious mechanic and an active observer of the weather, considered 

 that he was bound as a philosopher to assist; he therefore 

 determined to have a machine constructed that should record 

 by mechanical contrivances all the changes that take place in 

 the atmosphere at the time of the occurrence. After expending 

 many hundred pounds, he at last succeeded in producing an 

 instrument that would do the following work with a number of 

 pencils and zero pencils : — 

 Pencil 1 records the hour on the west edge of the paper. 



2 is the zero pencil for rain. 



3 records the commencement and termination of every 

 shower, and the amount of rain fallen every minute. 



4 is the zero pencil for evaporation. 



5 records the amount of evaporation every minute. 



6 is the zero pencil for temperature (marking the freezing 

 point) . 



7 records the temperature of the air every fifteen minutes. 



8 is a zero pencil for wind direction, drawing the zero of 

 a west wind. 



9 is a zero pencil for wind direction, drawing a north or 

 south wind according as the curve is convex or con- 

 cave on this line. 



10 is a zero pencil for wind direction, drawing the zero of 

 an east wind. 



11 records the wind's direction every minute. 



12 is the zero pencil for the force of the wind. 



13 records the force of the wind in oz. and lb. pressure 

 on the square foot every minute. 



14 \ are the zero pencils of the hygrometer, the one drawing 

 | the line of perfect dryness, the other that of perfect 



15 ) saturation. 



