THE WEATHER. 



supported in such a manner by the stand D, as to turn 

 with the wind, so that the orifice A is turned towards it. 

 The pressure of the breeze now upon the surface of the 

 water at F, forces it down in 

 the great tube, and conse- 

 quently up in the small tube, 

 C E. The height to which 

 it rises may be observed on 

 the scale at E, and indicates 

 the force of the wind. The 

 tube at B C is made very 

 small, in order to prevent sud- 

 den fluctuations of the sur- 

 face of the water at E. The 

 force and velocity of the wind 

 may both be obtained with 

 a good degree of accuracy 

 by this instrument. The 



It is by these means that the vapors drawn up iont 



