Diptych dial for latitudes 42°-54° North. Rectangular ivory dial consisting of two leaves that fold flat when not in use. Leaf Ia displays a standard windrose (see related terms) with a hand-shaped brass-index. The top left of leaf Ib carries a vertical dial with a brass pin gnomon. The top right has a vertical dial for planetary hours, also with a brass pin gnomon. Below is a table of latitudes for towns and cities in Europe. There are holes for the attachment of a string gnomon for different latitudes. Leaf IIa has five concentric hour scales. The centre of these dials is occupied by a scaphe dial with a brass pin gnomon, marked with hour-lines for Italian and Babylonian hours.

There is a compass in the southern part of the leaf marked with cardinal points in Latin. The magnetic variation is shown crudely by an arrow 10° West of North (this is a later addition). Michael Lesel's makers mark - a crown - appears either side of the centre. There is a rather frayed green string gnomon for use with the horizontal dial attached between the inner surfaces of the two leaves. Leaf IIb has a standard lunar volvelle surrounded by epact tables: the inner one for Gregorian epacts and the outer for Julian epacts, both for the year 1612. It is signed 'MICHAEL LESEL'.

This is one of only two diptychs in the collection carrying a dial for planetary hours on leaf Ib (the other is AST0155). The use of bright colours and decorations, such as flowers and putti-faced wind motifs, is typical of Lesel's work.

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