Photographs of Nebulæ and Clusters, Made with the Crossley Reflector

"Photographs of Nebulæ and Clusters, Made with the Crossley Reflector" by Keeler is a scientific publication written in the late 19th century. The work presents pioneering astronomical photography focused on capturing images of nebulæ and star clusters using the Crossley Reflector at the Lick Observatory. The book discusses the innovations in astrophotography and the significant discoveries made through these photographic endeavors. The opening of the volume begins with a note acknowledging some technical issues with original photographic plates, specifically regarding the visibility of dark rings around certain stars. Following this, the preface outlines Professor James Edward Keeler's ambitious plan to photograph various celestial bodies during his directorship at the Lick Observatory, detailing his success in capturing images of numerous nebulæ. It sets the stage for discussing the revolutionary findings regarding the existence of thousands of unrecorded nebulæ and their spiral structures, highlighting both the challenges and the advancements in observational techniques made during Keeler's time.