Portable horizontal dial for latitude 49° 27' North. The brass dial is circular, has a square base and is set over the compass. The dial-plate has a degree scale and an hour ring, marked 'Pour.49.Degres.27.M.' (for 49 degrees. 27 minutes). The dial-plate is open to allow a view of the compass. The gnomon, which is shaped and decorated with leaves, is supported by shaped and decorated struts and is hinged, folding flat when not in use. The compass consists of a raised degree scale and a set of cardinal points marked by isosceles triangles, with French names on the left and crosshatching on the right. North is marked by a fleur-de-lys. The needle is blued, in the form of an arrow, and surmounted by a brass pyramidal pivot. There is a glass plate over all.

This instrument allows easy adjustment to be made for changes in magnetic variation with the whole of the dial-plate being rotatable around the compass. The hour ring fits over the compass like a cover and thus can be rotated. The dial was probably intended for use in Rouen (49° 26'), or possibly in Le Havre (49° 30'). It is signed 'Delure AParis' on the dial-plate.

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