Excerpt from The Sun's Spotted Area, 1832 1900: A Statement of the Mean Daily Area in Each Synodic Rotation of the Sun, Based Upon Data Collected at the Solar Physics Observatory, South Kensington The published results of the reductions of solar photographs which have been made at Greenwich since 1873 include the mean daily areas for each year and for each synodic rotation, the latter being especially valuable in investigations for which a year is too great a unit of time. Similar data are also given by De la Rue in his manuscript reductions of the Kew series of photographs (1862 to and for this reason it has been decided to adopt a synodic rotation as the unit of time in constructing a new curve on the basis of spotted area. This curve has already been in use for some time at the Solar Physics Observatory, and it is thought that, together with the figures on which it is based, it may prove useful to other workers. The areas throughout are expressed in millionths of the sun's visible hemisphere. 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.