Excerpt from The American Journal of Science and Arts, Vol. 100: July, September and November, 1870 In the experiments Degreesust detailed the highest average sensitive ness of the eye is o y rim while as before shown in practical use the average difference from the mean is less than 35 3 of the whole. This higher degree of accuracy results naturally from the mode in which the com ensations are made, (alternately by approach and recession, ) an the fact that the compensations are t us interwoven, in such a manner as to eliminate errors intro duced by the slightly varying sensibility of the eye. Experiments on the amount of light transmitted by plates of glass at a perpendicular incidence. 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.