THE YOUNG SCIENTIST. 
is required to burst the cask. A few 
pounds at most are all that need be used, 
and strange to say— the larger the cask the 
more easily wiU it burst ! The latter is a 
139, 
exerts a pressure of so many pounds per 
square inch for every foot in height that 
it stands. If this pressure be 10 lbs. on 
each square inch and there are 10 square 
A -LESSON IN HYDKC STATICS, 
fact that very few can believe until after 
they have carefully studied the subject, 
but it is very easily understood when the 
correct view of the matter once presents 
itself to the mind. The water in the tube 
inches then the whole pressure is 100 lbs ; 
if there had been 100 square inches the 
pressure would have been 1,000 lbs. Hence 
the greater the number of square inches 
the greater is the pressure on the vessel, 
