I've been stalking antique prints/book pages documenting astronomical phenomenon of late, and this is one of the most beautiful I've found. It portrays "proturberances gazeuses du soleil," which I believe are also known as prominences: large, bright, gaseous features extending outward from the Sun's surface in the photosphere. These were observed, and drawn, by French astronomer Warren de la Rue during the total solar eclipse in 1860--and how beautiful they are, all the more so with one view stacked atop a second! 

The book plate is from a 1870 French volume I believe titled "Le Ciel" (the Sky). Color lithography on a nice weight paper and in very good condition. 6" x 10 1/8". The reverse side is blank.