196 



TUB KEiSON WHY. 



' Remember new thy creator in the days of thy youth." ECCLESIASTES n. 



but as the air does not enter freely the water cannot escape. It 

 therefore drops, as small portions of the air enter. 



859. Why cannot the handle be pressed in, if the Jinger IB 

 applied to the orifice ? 



Because water is not compressible, like air ; it must therefore 

 escape before the handle can be pressed in. Air may be forced into 

 a much smaller compass than is natural to it ; but it is impossible to 

 compress water in -any great degree. 



Fis?. 42. "SCCKEE." 



Fig. 43. HOOP. 



860. Why does a " sucker''' raise a stone ? 



Because underneath the sucker a vacuum is formed and the 

 external air, pressing on all sides against the vacuum, lifts the 

 stone. The term " sucker " is founded upon the mistaken notion 

 that the leather " sucks," or " draws" the stone. That such is 

 not the case is evident : if, when the stone is suspended, a pin's 

 point be passed under the leather, so as to open a small passage 

 for the air, the stone will drop instantly. 



861. Why does a hoop roll, without Jailing to the ground ? 

 Because the centrifugal force gives it a motion which is called the 



tangent to a circle that is, a tendency in all its parts to fly off in a 

 ttraight line. When a piece of clay adhering to the hoop flies off, 

 it leaves the hoop in a line which is straight with the part of 



