Peerless Perpetual Calendar By J L O'Connor Antique 1900 Centurial Years NY

Peerless Perpetual Calendar By J. L. O' Connor Vintage Centurial Years * Perpetual calendar, composed of two printed sheets of card-stock (17 x 11 cm). * The blue top-sheet, with seven die-cut windows (six circular and one rectangular); the top-sheet moves up-and-down via a brass-brad system of slits cut into the orange backing sheet. * Explanation text printed to back. * Devised by inventor J. L. O'Connor, "by the aid of which we may accurately determine the day of the week corresponding to any date from the beginning of the Christian era to A. D. 1600, by the Julian calendar (old style), and from the commencement of the Gregorian calendar (new style), Oct. 15, A.D. 1582, to A.D. 2699." Measurements (about): * Height: 7 in * Width: 4 1/4 in Condition: In good antique preowned condition with some wear on edges and corners (visible in the photos). Please look closely at the photos included with this listing for a true view of this item as I consider them part of the description. Ask any questions you may have. Please message me if you have any questions on this listing. I will reply shortly. Bundles Welcome! I welcome all reasonable offers. Ships promptly. To do my part in helping to keep our planet clean, most of my items are packaged and shipped in recycled materials. Thank you!