424 SUPPLEMENT. 



on the bottom when raised three times as high to c in 

 the tube. Put a fourth pound weight into the scale, and 

 it will cause the water to rise in the tube from c to d, 

 four times as high as it was when it was all contained 

 in the box, which shews that its pressure then upon the 

 bottom is four times as great as when it lay all within 

 the box. Put a fifth pound weight into the scale, and 

 the water will rise in the tube from d to e, five times 

 as high as it was above the bottom before it rose in the 

 tube , which shews that its pressure on the bottom is 

 then equal to five pounds, seeing that it supports so 

 much weight in the scale. And so on, if the tube was 

 still longer; for it would still require an additional 

 pound put into the scale, to raise the water in the tube 

 to an additional height equal to the space de; even if 

 the bore of the tube was so small as only to let the wire 

 move freely within it, and leave room for any water to 

 get around the wire. 



Hence we infer, that if a long narrow pipe or tube 

 was fixed in the top of a cask full of liquor, and if as 

 much liquor was poured into the tube as would fill it, 

 even though it were so small as not to hold an ounce 

 weight of liquor : the pressure arising from the liquor in 

 the tube would be as great upon the bottom, and be in 

 as much danger of bursting it out, as if the cask was 

 continued up, in its full size, to the height of the tube, 

 and filled with liquor. 



In order to account for this surprising affair, we must 

 consider that fluids press equally in all manner of 

 directions; and consequently that they , press just as 

 strongly upward as they do downward. For, if another 

 tube, as /, be put into a hole made into the top of the 

 box, and the box be filled with water ; and then, if water 

 be poured in at the top of the tube abode, it will rise 

 in the tube^ to the same height as it does in the other 

 tube : and if you leave off pouring, when the water is a- 



