Excerpt from The Luminous Equivalent of Radiation But, while the heat equivalent of mechanical energy is a fixed quantity, the luminous equivalent of radiation varies enormously with the wave length of the radiation concerned and to a slight ex tent with its intensity as well. The principle of the conservation of energy does not apply to light, either objective or subjective. Light is not a simple multiple of radiation, but a complicated func tion of its quality, quantity, and duration. This article is devoted to the formulation of these complex relations. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.