This is so contrary to our ordinary experience and ideas, in

which loss of heat tends to change from gas to fluid and solid,
that we must look into it a little to make it sound reasonable
This is so contrary to our ordinary experience and ideas, in
which loss of heat tends to change from gas to fluid and solid,
that we must look into it a little to make it sound reasonable.
The recent brilliant work of P. W. Bridgman (contrary to the
earlier speculations of Tammann) indicates that the effect of
increased pressure, at high temperature, makes a substance
solid and crystalline. Crowd any atoms close enough together,
and no matter how fast they expand or contract under the
influence of heat the crystalline atomic forces will get to
work when they are crowded within their range, and the closest
packing, hence that which will yield most to the pressure,
hence that which is likely to take place, is when they are all
regularly arranged facing the same way. Such an arrangement we
call crystalline. Just so when they want to pack the most
people into the car of an elevator they ask them to all face to
the front. Keep this metaphor a moment. Any one who should try
to penetrate such a crowd would find it a hard job. They would
offer a very effective rigidity. Now suppose them to sweat in
those confined quarters their fat away, their phlogiston, their
caloric. If the walls of the car remained rigid while the
individuals therein shrunk they might after a while be able to
turn around or even move around in a car. Such is then the
supposed condition of the atoms in the FOURTH, the central,
layer of the earth"s crust. This assumes that the middle layer
is rigid and sustains itself, like the shell of a nut, as in
the figure, while within the atoms are in a less rigid
condition. That such a shell might be self-sustaining is
suggested by an experiment of Bridgman, who put a marble with a
gas bubble in it under a pressure of something like 150,000
pounds to the square inch without producing any perceptible
change.