My library dates back to 1904, shortly after Dr. George Ellery Hale came west from Yerkes Observatory to the sleepy little town of Pasadena, California to start the Mount Wilson Solar Observatory. The classification system used in this new library was published for the International Council by the Royal Society of London. Over time the librarians managed to acquire many complete runs of observatory publications from all over the world, and they were arranged alphabetically according to the place where they were published. University publications have been included in this collection as well.