The Diffuse Reflecting Power of Various Substances (Classic Reprint)

Bücher

Angebote / Angebote:

Excerpt from The Diffuse Reflecting Power of Various Substances Three methods have heretofore been used in determining the amount of energy lost by diffuse re¿ection from rough surfaces. The first method is based upon the assumption that the diffusion follows the cosine law. The amount of incident energy is measured, also the amount of energy re¿ected at a given angle from the normal. By integration the total amount is obtained that is lost by diffuse re¿ection. This method was used by Angstrom.8 He used a surface bolometer at an angle of and found that for a thickly sooted platinum black surface the re¿ecting power varied from per cent to I 2 5 per cent, being apparently larger for the short wave lengths. Practically the same method was used by Hutchins.° With a radiomicrometer he investigated the cosine law of diffuse re¿ection of various substances. He found that the diffusion from rough surfaces of such substances as magnesium oxide and plaster departed an appreciable amount from the cosine law, for large angles, while for paper this departure was very marked for angles between 20° and By integration he found the total amount of energy lost by diffusion. For a white surface, plaster, using sunlight as a source of energy, the integrated value for the re¿ecting power (the albedo) was for paper it was and for a green leaf it was which values are in fair agreement with the results of the present research. 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.