- Author: SELLER, John and ALLEN, Elias
- Publication place: [London
- Publication date: c.1640].
- Physical description: 200mm (8 inch) diameter double horizontal brass sundial, octagonal form, the corners pierced for screws, engraved plate for solar declination and hours, gnomon underpinned at centre, bearing later signature of John Seller, over-signed in the chapter ring “Jon. Seller excut Londini”.
- Inventory reference: 1594
“Up betimes, and studying my double diall… Dean Honiwood comes to me, who dotes mightily upon it and I think I must give it him.” And on the 4th June: “Home by water, where by and by comes Dean Honiwood, and I showed him my double horizontal diall, and promise to give him one, and that shall be it”.
Elias Allen (c.1588–1653) was apprenticed to Charles Whitwell of the Grocers’ Company. He was renowned in his day and had a close relationship with contemporary mathematicians. He joined the Clockmakers’ Company in 1633 and became their Master in 1637–8. He produced a wide range of precision measuring instruments.
John Seller (1632–1697), in addition to being a leading mathematical practitioner and mapmaker of his day, was also something of a colourful character — or rogue — who enjoyed the Royal patronage one year, and was jailed in Newgate the next. It seems that he may have acquired the remaining stock of Allen’s workshop on his death in 1653 and passed a few instruments off as his own work — certainly this is the only known dial that bears his signature and, when examined closely and compared to other Allen dials, has even incorporated elements of Allen’s signature.