Paul S. Epstein (1937)
Textbook of Thermodynamics by Paul Sophus Epstein, published by John Wiley & Sons, Inc., New York, and printed in the USA. This finely preserved copy is a 5th printing from March 1949.
Paul Sophus Epstein was a Russian-American mathematical physicist who played a significant role in the development of quantum mechanics. In 1921, while working as an assistant to Lorentz and Ehrenfest in Leiden, he was recruited by Robert Millikan (of charge-on-the-electron fame) to come to Caltech, where he remained for the rest of his career. More about Epstein can be read here.
In the preface to the book, Epstein writes “This book treats thermodynamics from the point of view of the physicist and has a twofold purpose. One half of it is intended as a text in a basic course for seniors and younger graduate students. The other half may be used for reference or in special courses given to more advanced listeners.”

A typical page from the 400+ page book, which is arranged in 22 chapters. As a physicist, Epstein elected to use a bold capital X to symbolize enthalpy since to him, H represented electromagnetic field strength. Click on image for a larger view.