BUOYANCY. 133 



(a.) Insert a short spout in the side of a vessel (as a tin fruit-can) 

 about an inch below the top. Fill the vessel with water and let all 

 above the level of the spout escape. This is to replace the vessel 

 of water in which a (Fig. 80) is immersed. Instead of the bucket, 

 6, use a cup placed on the scale pan. Instead of a, use any con- 

 venient solid heavier than water, as the fragment of a stone. Coun- 

 terpoise the cup and stone in the air. Immerse the stone in the 

 water and catch, in any convenient vessel, every drop of water that 

 overflows. This will be the fluid that the solid displaces. The 

 equilibrium is destroyed, but may be restored by pouring the 

 water just caught into the cup on the scale-pan. 



24O. Floating Bodies. When solids of different 

 densities are thrown into a given liquid, those having den- 

 sities greater than that of the liquid 

 will sink, because the force of gravity 

 overcomes the buoyancy of the liquid ; 

 those having densities equal to that of 

 the liquid will remain at rest in any 

 position in the liquid, because the op- 

 posing forces, gravity and buoyancy, 

 are equal; those having densities less FIG. 81. 



than that of the liquid will float, because the force of 

 gravity will draw them down into the liquid until they 

 displace enough of the liquid to render the buoyant effect 

 equal to the weight. Hence, a floating body displaces 

 Us own weight of the fluid. This may be shown ex- 

 perimentally by filling a vase with water. When a float- 

 ing body is placed on the surface, the water displaced will 

 overflow and may be caught. The water thus caught will 

 weigh the same as the floating body. 



(a.) Place the tin vessel with a spout, mentioned in the last 

 article, upon one scale-pan, and fill it with water, some of which 

 will overflow through the spout. When the spout has ceased 

 dripping, counterpoise the vessel of water with weights in the 

 other scale-pan. Place a floating body on the water. This will 



