ICEBERGS 373 



the beaker a piece of ice, and catch in another beaker the water 

 which runs out. After all the water which readily overflows has 

 been caught in the second beaker, carefully push the ice into the 

 water till it is entirely submerged, and catch in a third beaker the 

 water which overflows. The experiment must be done with consid- 

 erable quickness, so that the ice will not melt between the two 

 steps. 



The water in the second beaker is equal to the volume of the ice 

 submerged when it floats, and that in the third beaker to the volume 



AN ICEBERG. 



of the part out of water when the ice floated. The two together are 

 equal to the whole volume of the ice. Measure in a graduate or 

 weigh on a balance these two volumes of water. (A cubic centi- 

 meter of water weighs a gram.) Determine the part of a floating 

 block of ice that is out of water. Would the amount of ice out of 

 water be greater or less if the water were salt? This can be demon- 

 strated by dissolving a considerable quantity of salt in the ice water 

 and very rapidly repeating the experiment. 



When a glacier extends out into the sea, the water tends 

 to float the ice. If it extends out into deep enough water, 

 the buoyancy of the water will be sufficient to crack the ice, 



