[The
Lecturer poured the cold water over the vessel, when it immediately
collapsed.] You see what has happened. If I had closed the stopper, and
still kept the heat applied to it, it would have burst the vessel; yet,
when the steam returns to the state of water, the vessel collapses, there
being a vacuum produced inside by the condensation of the steam. I shew
you these experiments for the purpose of pointing out that in all these
occurrences there is nothing that changes the water into any other
thing--it still remains water; and so the vessel is obliged to give way,
and is crushed inwards, as in the other case, by the further application
of heat, it would have been blown outwards.
[Illustration: Fig. 12.]
And what do you think the bulk of that water is when it assumes the
vaporous condition? You see that cube [pointing to a cubic foot]. There,
by its side, is a cubic inch, exactly the same shape as the cubic foot,
and that bulk of water [the cubic inch] is sufficient to expand into that
bulk [the cubic foot] of steam; and, on the contrary, the application of
cold will contract that large quantity of steam into this small quantity
of water.
[Illustration: Fig. 13.]
[One of the iron bottles burst at that moment.] Ah! There is one of our
bottles burst, and here you see is a crack down one side an eighth of an
inch in width.
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