Lighthouse Construction and Illumination #223613

IN the following pages I have done my best to give a condensed statement, lst, Of the facts and principles which regulate the design and construction of Lighthouse Towers in exposed situations and 2d, Of the practical application of optics to Coast Illumination. The history of the introduc tion of the optical agents, and their combinations to meet different requirements, have, so far as consistent with a clear exposition and division of the subject, been arranged in the chronological order of their publication, or of their employ ment in Lighthouses.