This text examines the physical distinction between heat conduction and heat radiation, noting that radiation is independent of the medium through which it passes. It establishes that heat rays are physically identical to light rays and applies the principles of experimental optics to the study of thermal radiation.

This text examines the physical distinction between heat conduction and heat radiation, noting that radiation is independent of the medium through which it passes. It establishes that heat rays are physically identical to light rays and applies the principles of experimental optics to the study of thermal radiation.