CORRECTION TO BAROMETER FOR FORCE OF WIND. 381 
of water through the larger tube; and, in No. 5, that the water descending ver- 
tically in the large tube, draws up the water vertically through the smaller. 
Fig. 5. 






































Whilst these experiments illustrate each other, they also serve to illustrate 
the cause of the depression in the barometer during gales of wind ; for the rush of 
a stream of wind over and around any house or ship, as shewn in figs. 6 and 7, 
Fig. 6. 

Fig, 7. 

must have the same effect of drawing out the air and producing a partial vacuum 
VO. XX. PART III. 51 

