Quarto. 48pp + 70 plates. A tremendous feat of both astrophotography and its reproduction, here labeled "heliogravures" to get the cosmic point across. The Crossley Reflector was used at the Lick Observator from 1895 to 2010, and was at the time of its arrival in California the largest glass reflecting telescope in the United States. It used a 36-inch mirror made by George Calver for A. A. Common, and was among the first entries into the succession of large metal-coated glass mirrors, rather than cast speculum metal mirrors, to capture detailed images of nebulae. Keeler had been director of the observatory until his death in 1900, when W. W. Campbell took on the role. Campbells TLs to the Photogravure & Color Co. of New York commends their expert reproductions from the negatives and mentions awaiting the copper plates. Bound in full pebbled black cloth over boards. Some overall rubbing, spine sunned, else very good. Bookplate to front pastedown, former owner's inscription to front flyleaf.