B1794 Wm. M Christy’s Sons Advertising Blotter, From Wikipedia:  Christy died January 9, 1866 with presumably his son William assuming operations of the business. By 1878, the firm was renamed William M. Christy's Sons and under the proprietorship of William and Joseph Christy who resided at 3909 Spruce Street (West Philadelphia). The firm was still active as of 1896 at 312 Chestnut Street.) This is a very nice, early advertising blotter for Flat Opening Blank Books sold by Wm. M. Christy’s Sons in Philadelphia. White blotting paper, measures 9.5 x 4.75 inches. Black print on white.