Pennsylvania, Philadelphia. Rockhill & Wilson. Mechanical calendar. Bowers PA-4215. Gilt brass. 39 mm. Choice About Uncirculated.,Obverse: Mechanical calendar with numbers and inscription, JOHN DAVEY / PHILADA. / COPY RIGHT SECURED. Reverse: Seven-line embossed advertisement, ROCKHILL & WILSON / TAILORS & / CLOTHIERS / MEN & BOYS WEAR / No. 603 & 605 / CHESTNUT ST. / PHILADELPHIA. A couple of small dents are noted, but mostly the surfaces are well preserved with most of the original gilding intact and some golden brown toning. An interesting mechanical form, though the insert bearing the days of the week does not seem to rotate easily. Another rarity, both as an issue and form. Noted by Bowers as the only one see, and the plate piece in his reference.,Ex Ralph Mitchell Collection; Jess Peters; Ray Byrne Estate; David Schenkman, January 1983; Steve Tanenbaum, 2011; Q. David Bowers Collection.,