The moon : $b a full description and map of its principal physical features

"The Moon: A Full Description and Map of Its Principal Physical Features" by Thomas Gwyn Elger is a scientific publication written in the late 19th century. The work serves as an extensive guide for lunar observers, illustrating the moon's physical characteristics and providing detailed maps for reference. The book is tailored for both serious astronomers and those with a general interest in astronomy, aiming to enhance understanding of the moon's surface features. The opening portion of the book sets the stage for an in-depth exploration of lunar topography, emphasizing the work's dual purpose as a reference for telescopic observation and a means of organizing lunar research. Elger discusses the advancements in lunar observation since Galileo's time, acknowledging the contributions of various astronomers who have mapped and named lunar features. He introduces the various categories of lunar formations, such as maria (seas), ridges, craters, and rills (clefts), while highlighting the significance of those observations in the study of selenography. The preface articulates the need for systematic observation techniques, presenting a foundation upon which the subsequent chapters build deeper insights. (This is an automatically generated summary.)

Thomas Gwyn Empy Elger FRAS was a British selenographer and one of the preeminent lunar observers of the Victorian age, best known for his lunar map, which was regarded as one of the best available until the 1960s. He was the first director of the Lunar Section of the British Astronomical Association (BAA), and is remembered by the lunar crater Elger.