Irving's catechism of astronomy
A question-and-answer school primer on astronomy by Christopher Irving, revised by Anselm Ortmann and issued by J. Murphy Company of Baltimore and New York in 1905 for classroom use. Its plates are white-on-black star charts with constellation figures joined by dotted lines, hand-lettered names curving through the field, and stippled clusters and nebulae usable as night-sky textures and celestial diagrams.
