As a student poking around the basement of the science library I
stumbled upon a mysterious book bound in brown cloth - or did it
stumble upon me? Anyhow the faded title was 'Rational Thermodynamics',
the author Clifford Truesdell (or Clifford Ambrose Truesdell III
in full). I didn't know it at the time but I was to spend many
months over many years, on and off, trying to decode this book. I
must have read the first chapter more than fifteen times by now and
I still have only the basics of it down (and perhaps not even that).

Truesdell has a very distinctive approach to thermodynamics, which
uses differential equations for good old-fashioned functions of
time rather than the usual slightly mysterious sequences of states
moved between infinitely slowly. I found the idea of the approach
very appealing and physically very intuitive but some accidental
features made the book very hard for me to understand, including
the exotic terminology (e.g. using caloric for entropy) and notation
(lots of Fraktur letters). The writing style is really fun to read
though, very flowery, although Truesdell can be a bit mean about
other people.

I felt physically quite hungry to understand what was going on, so
I tried reading some other Truesdell books. After reading his
'Tragicomical history of thermodynamics' (scathing but very
theoretically detailed) and 'The concepts and logic of classical
thermodynamics as a theory of heat engines' (developing thermodynamics
from webs of Carnot cycles, written together with Subramanyam
Bharatha), I gradually began to feel that I had more of a handle
on it.

The thermodynamics notes I have been working on are largely an
effort to get my thoughts on Truesdell's Rational Thermodynamics
straightened out (and also a chance to have some fun with differential
forms). I can't count the hours I've spent thinking about it; perhaps
if it wasn't for the brown cloth covers I would never have picked
up the book and saved myself a lot of trouble... although the thought
of that makes me queasy.