Excerpt from Notes of a Course of Nine Lectures on Light: Delivered at the Royal Institution of Great Britain, April 8 June 3, 1869 These Notes were prepared for the use of those who attended my Lectures on Light last year, and were t intended for further publication. Enquiries and requests regarding them from teachers and students who have read them, cause me w to think that the Notes may be useful beyond their contemplated limits. The Messrs. Longman have therefore undertaken their publication in a very cheap form. To my friend Professor Goodeve, who has been kind eugh to look over the proofs, my best thanks are due and tendered. 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 techlogy 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.