80
REVIEW
OF
BRYAN
parts
of
a
system
can
be
regarded
as
being
in
equilibrium;
a
similar
objection
is raised with respect
to
the heat supplied.
Doc.
9
Review
of
G. H.
BRYAN,
"The
Law
of
Degradation
of
Energy
as
the
Fundamental
Principle of
Thermodynamics" ("Das
Gesetz
von
der
Entwertung
der
Energie
als
Fundamentalprinzip
der
Thermodynamik,"
in
Meyer,
S., ed.,
Festschrift.
Ludwig
Boltzmann
gewidmet
zum
sechzigsten
Geburtstage
20.
Februar
1904.
(Leipzig:
J.A.
Barth,
1904): 123-136)
[Beiblätter
zu
den
Annalen
der
Physik 29
(1905):
237]
The
author
starts
out
from the
energy
principle
as
well
as
the principle
of the decrease of
free
energy.
The
free
energy
(available
energy)
of
a
system
is defined
as
the
maximal
mechanical
work
that
the
system
can
perform
during
changes
compatible
with the external conditions. This
is
followed
by
the definition of heat
supplied to
the
system.
Then
the
concept
of thermal
equilibrium, the
second law,
the
concept of
absolute
temperature, and
the
concept
of
energy
are
developed
from
the
stated fundamental principles
in
an
elegant
way,
and,
finally,
the
equations of
thermodynamic
equilibrium
are
derived.
[1]