xi should hope for "first and foremost" from any historical
investigation, including his own, was that "it may not be too tedious. "
II That hope is generally realized in Mach's historical writings, most
of which are as lively and interesting now as they were when they
appeared. Mach did not follow any existing model of historical or
philosophical or scientific exposition, but went at things his own way
combining the various approaches as needed to reach the goals he set for
himself. When he is at his best we get a sense of the Mach whom William
James met on a visit to Prague, the Mach whose four hours of
"unforgettable conversation" gave the forty year old, well traveled
James the strongest "impression of pure intellectual genius" he had yet
received, and whose "absolute simplicity of manner and winningness of
smile" captivated him completely. 12 Consider, for example, the first
few chapters of this book, Principles of the Theory of Heat, which Mach
devotes to the notion of temperature, that most fundamental of all
thermal concepts. He begins by trying to trace the path that leads from
our sensations of hot and cold to a numerical temperature scale.