You can very easily perceive that the flask is
quite full of steam, or else it would not force its way out. You see,
also, that the flask contains a substance very much larger than the water,
for it fills the whole of the flask over and over again, and there it is
blowing away into the air; and yet you cannot observe any great diminution
in the bulk of the water, which shews you that its change of bulk is very
great when it becomes steam.
I have put our iron bottles containing water into this freezing mixture,
that you may see what happens. No communication will take place, you
observe, between the water in the bottles and the ice in the outer vessel.
But there will be a conveyance of heat from the one to the other; and if
we are successful--we are making our experiment in very great haste--I
expect you will by-and-by, so soon as the cold has taken possession of the
bottles and their contents, hear a pop on the occasion of the bursting of
the one bottle or the other; and, when we come to examine the bottles, we
shall find their contents masses of ice, partly enclosed by the covering
of iron which is too small for them, because the ice is larger in bulk
than the water. You know very well that ice floats upon water: if a boy
falls through a hole into the water, he tries to get on the ice again to
float him up.
Pages:
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63