Butterfield dial for latitudes 40°-55° North. Standard three-scale dial (see related terms) except for the following details:-

It has an oval plate. The scales are marked for 55°, 51° and 45°.The central section is engraved with the arms of the Earl of Orrery which includes lions and the family motto: 'HONOR VIRTUTIS PREMIUM' (Honour is the reward of virtue). The compass has cardinal points marked by English initials and the North point is offset 10° West of North to allow for magnetic variation. The replacement needle is surmounted by a cylindrical pivot set with a red stone. The gnomon, engraved with leaves which transform into a bird head at the centre, is adjustable for latitudes 40°-55°. On the reverse is a table carrying the equation of time in two columns. It is signed 'J. Rowley LONDINI'.

In some ways, one might consider this to be the pair of AST0392. It was made for Charles Boyle, the fourth Earl of Orrery, and carries his arms. Unusually for a Butterfield dial, the table of latitudes on the back is replaced with a table for the equation of time, for the l0th, 20th and 30th of each month. The Earl of Orrery had a large collection of scientific instruments, all of which are now in the Museum of the History of Science in Oxford. The fact that this sundial was not part of that collection suggests that it might have been used regularly by the Earl for timekeeping, and was not kept as a scientific curiosity. It has a black leather case.

For more information regarding this dial please refer to the OUP & NMM catalogue, 'Sundials at Greenwich'.