Sun-and-moon dial made by Elias Allen between 1607 and 1653 at his workshop, near St. Clement's Church, London. Engraved "Elias Allen fecit a Moone diall". It is callibrated for use at the latitude 51 1/2.
Sun-and-moon dials are time-reckoning devices that can be used in daylight as sundials and at night as moondials. This example was made by Elias Allen (active 1602-1653) at his workshop known as 'The Bull's Head' which was situated near St. Clement's Church, near the Strand in London. Allen was a mathematical instrument maker who moved to London from Tonbridge in Kent to take up an apprenticeship with Charles Whitwell in around 1602.