Max Planck 
The Origin and Development of the Quantum Theory by Max Planck with a Chapter on Heat Radiation [EPUB ebook] 

Planck made many contributions to theoretical physics, but his fame as a physicist rests primarily on his role as the originator of quantum theory, which revolutionized human understanding of atomic and subatomic processes. The book is part of his 1920 Nobel Prize Address on the Origin and Development of the Quantum Theory and involves a detailed chapter on Heat Radiation.