SELLER, John. [Engraved Perpetual Calendar. London, c. 1680].
Engraved plate (c. 198 × 128 mm), with contemporary hand colouring, mounted on thick card with two cut ‘windows’ and two revolving volvelle dials worked with wooden rundles behind. Contemporary or original fruitwood frame and wooden back, glazed. Right hand margin with some fraying, just affecting right hand end edge of engraved border, one closed tear or crack to left hand margin.
AN EXCEPTIONALLY RARE ENGLISH CALENDAR WITH TWO REVOLVING DIALS (one giving the date, the other, the month with its corresponding number of days), APPARENTLY KNOWN IN ONLY ONE OTHER COPY. Each dial is operated with original wooden ‘rundles’ turned by hand on the back of the frame. Around the central calendar and dial are emblematic figures of the gods representing the days of the week: Apollo (Sunday), Diana (Monday), Mars (Tuesday), Mercury (Wednesday), Jove or Jupiter (Thursday), (Friday) and Saturn (Saturday).
John Seller (1632-1697), whose initials appear at the foot, and his full name in the globe at the head, was one of the most important mapmakers and makers of scientific instruments in seventeenth-century London. Examples of paper instruments made by him are exceptionally rare, and while the perpetual calendar may have been one of his simplest offerings in this line it probably had the widest appeal. However many copies he printed, its rarity is understandable: we can find no example of this calendar in library catalogues, though a similar calendar (also framed, with rundles, but uncoloured) appeared in the British trade several years ago (then described as possibly unique). The estimated date of production is approximate, and based partly on Seller’s output of pocket almanacs and similar (at least one issued with volvelles) in the 1680s. The presence of his initials as well as imprint suggests that the engraved design is Sellers’ own.
He operated throughout his documented career from premises at the Hermitage Stairs in Wapping, but for a number of years maintained additional retail premises in and about the Royal Exchange. He was a member of the Clockmakers Company from 1667 and served as its warden from 1692-6. Samuel Pepys was a regular customer, mentioning Seller more than once in his diary.

Condition
Excellent