Magnetic dial for latitude 51° North. This miniature dial is set on a magnetic compass card with a round brass base containing the dial. There are 32 marked compass points, unnamed apart from 'S', 'W' and 'E'. The hour ring, within the compass points, is numbered clockwise V-XII, I-VII; there is a sunface at the South point and a simple brass gnomon. It has a domed glass cover over all.

This is the smallest dial in the NMM collection. It is hard to see that it could have fulfilled any useful purpose for time-telling, and it was probably intended as a toy or a trinket (possibly a gift for a lady or a child).

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