Excerpt from Notes on Standard Wave Lengths Spectrographs, and Spectrum Tubes The weight assigned to each value is based up0n the mumbe1 of observations with relatively large orders 0f interference and is therefore indicative of the probable relative accuracy. From the concordance among difierent sets of observations on the well determined lines it appears that the probable errors in these are less than 0. 001 A, although our value 01 4799 exceeds Michelson's by 0. 005 A. 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.