OF FLOATATION AND THE SPECIFIC GRAVITY OF BODIES. 225 



its own weight and that of an equal bulk of the fluid, and has there- 

 fore lost the weight of as much fluid. 



253. INF. 2, When a solid body is immersed, or suspended in a 

 fluid of the same, or of different specific gravity : 



It loses the whole or a part of its weight, according as it 

 is totally or partially immersed, and the fluid gains the weight 

 which the body loses. 



This is manifest, for the sum of the weights of the body and the 

 fluid must be the same, both before and after the immersion. 



254. INF. 3. If bodies of equal magnitude are placed in the same 

 fluid, whatever may be their specific gravities : 



They lose equal weight, and unequal bodies lose weights 

 that are proportional to their magnitudes. 



255. INF. 4. If the same body be immersed, or suspended in fluids 

 of different specific gravities: 



The weights lost by the body are as the densities or specific 

 gravities of the fluids. 



256. INF. 5. When two bodies of unequal magnitude are in equilibrio 

 with one and the same fluid : 



They will lose their equilibrium, if they be transferred to 

 another fluid of different density. 



257. INF. 6. When a body ascends or descends, in a fluid of greater 

 or less specific gravity than itself: 



The force which accelerates its ascent or descent, is equal 

 to the quotient that arises, when the difference between the 

 weight of the body, and that of an equal bulk of the fluid, is 

 divided by the common magnitude. 



It consequently follows, that when the solid is entirely immersed in 

 the fluid, the force which urges its ascent or descent is constant; in 

 which case, the motion upwards or downwards must be uniformly 

 accelerated, if it be not disturbed by the resistance of the medium in 

 which it moves. 



258. If the solid is specifically heavier than the fluid, it will tend 

 downwards, and press the bottom of the vessel, with a force which is 

 equivalent to the excess of its weight above an equal bulk of the 

 fluid ; and this is what we understand by the relative giavity of the 

 body in the fluid. 



But if the body be specifically lighter than the fluid in which it is 

 placed, it seems to lose a greater weight than it actually possesses, 



VOL. I. Q 



