"Prime meridians are Washington D.C. and Greenwich. The special ""propeller"" border Mitchell Atlas - all the maps have this unique border not found in any other Mitchell Atlases. The title says this atlas was ""Designed To Accompany And Illustrate The Centennial Gazetteer Of The United States,"" also published, we assume, by Ziegler & McCurdy, although we can find no reference to it. The maps in the atlas are sometimes unique issues, different from the maps found in the Mitchell General Atlas of either 1874, 1875, or 1873. Only maps of the United States are included, except for three World maps. Full color."