THE EARTH. 165 



fact, a body attempting to sink upon water, at a 

 depth of forty feet, with the pressure from above 

 taken away. The water, therefore, will over- 

 come my strength, and will continue to burst in 

 till it has got to its level : if I should then dive 

 into the hold, and clap my hand upon the open- 

 ing as before, I should perceive no force acting 

 against my hand at all, for the water above presses 

 the hand as much down against the hole, as the 

 water without presses it upward. For this rea- 

 son, also, when we dive to the bottom of the 

 water, we sustain a very great pressure from 

 above, it is true, but it is counteracted by the 

 pressure from below ; and the whole acting uni- 

 formly on the surface of the body, wraps us close 

 round without injury. 



As I have deviated thus far, I will just men- 

 tion one or two properties more, which water, 

 and all such like fluids, is found to possess. And 

 first, their ascending in vessels which are emp- 

 tied of air, as in our common pumps for instance. 

 The air, however, being the agent in this case, 

 we must previously examine its properties, before 

 we undertake the explanation. The other pro- 

 perty to be mentioned is, that of their ascending 

 in small capillary tubes* This is one of the most 

 extraordinary and inscrutable appearances in na- 

 ture. Glass tubes may be drawn, by means of a 

 lamp, as fine as a hair ; still preserving their hol- 

 low within. If one of these be planted in a ves- 

 sel of water, or spirit of wine, the liquor will im- 

 mediately be seen to ascend j and it will rise 

 higher, in proportion as the tube is smaller; a 



