THE YOUNG SCIENTIST. 
43 
dian boils water and makes soup in aj 
basket ! The basket is so well made that 
it is water tight— just like a wooden pail, 
and holds water or soup, or any other 
liquid ! But he does not hold the basket 
over the lire ; he puts the fire in the bas- 
ket, and he does this by heating smooth 
stones quite hot, and then plunging them 
in the liquid. In. this way he soon makes 
the water boil. 
As a curious example of 1] eating water 
in a wooden vessel, we may mention the 
! thus : To boil water in a common tumbler 
over a lamp or gas flame. This is easily 
accomplished as follows : Over the mouth 
of a tumbler full of water place a sheet of 
close-grained paper ; press it on tightly, 
and quickly invert the tumbler. Instead 
of the water falling out, it will remain in 
place, and the paper will not fall off. The 
inverted tumbler may then be held over 
the lamp, when the heat will pass readily 
through the paper, which will not be 
burned, however, and the water will 
MELTING METAL IN A CAED. 
first steam boilers made in this country. 
Iron was then scarce and dea,r, and the 
facilities for working it were not very 
good, so Oliver Evans made his steam 
boilers of wood, just like so many barrels, 
and through them he passed iron tubes. 
These tubes conve^^ed the flame and hot 
smoke, so that the water was quickly 
heated and steam raised. On the whole, 
although they were not equal to our mod- 
ern iron and steel boilers, these w^ooden 
boilers were very serviceable. 
Another curious problem may be stated 
quickly become hot. And now comes a 
curious point in this experiment. As soon 
as the w^ater boils and steam is formed 
above it in the tumbler, the pressure of 
the air, which formerly held the paper 
and water in place, is counterbalanced, 
and both paper and water fall to the 
ground. To prevent this, if we desire to 
carry the heat to the boiling i^oint, we 
must tie the paper firmly over the mouth 
of the tumbler, and we can then raise the 
water to the boiling point with safety. 
But we must not make it any hotter than 
