HANDBOOK OF OPTICS

For Students of OphthalmologyThe question as to the method of transmission of light has been the subject of much controversy. Leaving aside the speculations of the ancients, the two theories are the Corpuscular or Emission The ory and the Wave Theory. The first supposes a luminous body to give off certain particles, which, striking the eye, produce vision. The wave theory supposes that all space is pervaded by a substance called ether, and that by means of this substance, waves, excited in the luminous body, are transmitted to the eye. While some of the phenomena of light can be explained by either theory, experiments by Huyghens, Young, and Fresnel have rendered the emission theory untenable. While we are forced to the belief that light is propagated in waves, we are ignorant as to the nature of these waves. It was formerly supposed that the ether was a highly elastic body, transmitting vibrations of its particles through space just as a rod of steel, if struck near one end, will convey the vibrations to the other end.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.