The history of this specimen is unknown. I found it among some old documents. It consists of a disc of parchment 1⅜ in. in diameter, having the Arabic numerals 1 to 4 inclusive on either side, the 4 being of early looped form. This disc is pivoted between two semicircular leaves of a folded piece of parchment which cover three figures on either side of the disc, but leave the fourth exposed. These semicircular pieces of parchment have on one side the symbols of the sun, moon, and stars (fig. 1), and on the other side the sun only with the words ‘Rota versatil(is)’ in a cursive hand of the fifteenth century (fig. 2); the last two letters (is) are represented by a general sign of contraction. There is also a loop at the back through which a strip of parchment about ½ in. wide and 11½ in. long is threaded. The whole forms such a bookmarker as a skilful penman might make out of a few scraps of parchment in his leisure hours as an aid to his work.