192 CELESTIAL MECHANICS. I. iii. 17. 



some particles of the fluid may be so arranged as to be no 

 more disturbed in their initial tendency to motion than the 

 fluid in such a tube would be, the equilibrium can never 

 be permanent, unless the pressures be such as are here 

 assigned. 



Scholium 1. If therefore any portion of the superior 

 part of a fluid be replaced by a part of the vessel, the 

 pressure against this from below will be the same which 

 before supported the weight of the fluid removed, and, 

 every part remaining in equilibrium, the pressure on the 

 bottom will be the same as if the horizontal section of the 

 vessel were every where of equal dimensions. In this 

 manner the smallest given quantity of a fluid may be made 

 to produce a pressure capable of sustaining a weight of 

 any magnitude, either by diminishing the diameter of the 

 column and increasing its height, or by increasing the 

 surface which supports the weight: a property which has 

 been called the hydrostatic paradox, and which is the 

 foundation of the construction of Bramah's powerful 

 presses. 



Scholium 2. These properties may be still further 

 illustrated by imagining a vessel to be made of ice, and to 

 be immersed in a larger reservoir of water, and then 

 thawed : in this case the water will make a part of the 

 general contents of the reservoir, and consequently will 

 remain at rest, if its surfaces are level with that of the 

 reservoir : and it is obvious that the vessel has acquired no 

 new power of supporting the pressure from being thawed: 

 consequently the water will stand at the same height in 

 every part of the vessel of ice as if it had remained water; 

 exerting the same pressure on the sides of the vessel, as if 

 it had to react against the weight of a fluid column imme- 



