The Richard II Quadrant

England, AD 1399

An astronomical instrument made for King Richard II

This is the most spectacular of a group of three horary quadrants of very similar design. The roundel on the front, depicting a stag with a crown around its neck and a chain around its body, identifies this as an object made for Richard II, King of England (reigned 1377-1399). Richard II's use of this badge is well documented and can also be seen on another object in the Museum, the renowned Asante jug. The second quadrant in the group, dated 1398 and now in the Dorset County Museum in Dorchester, is likely to have been made for Richard's half brother, John Holland. Although we are able to date the third quadrant in the group to 1400, we are unable to say for whom it was produced.

The tables on the back of the quadrant, which give the height of the sun at midday throughout the year, enables us to say that the instrument was made for us in London. There is some debate, however, whether this quadrant is the same as that mentioned in the inventory of Richard's possessions, compiled in 1399 shortly after his death.

An horary quadrant enables the user to tell the time from the height of the sun. This particular instrument also has on the back a circulat table that would have facilitated the calculation of the date of Easter. The abbreviated words circumscribing this table are a short form of a Latin mnemonic that reminds the reader of the date of Easter, one of the most important of Christian Feasts. Other moveable feasts such as Pentecost depend on the date of Easter, making this quadrant an extremely useful device to have.

The quadrant shows traces of gilding towards the tip and its fine execution shows that it was made for a wealthy client. Instruments in the Middle Ages were always made to special commission rather than ready made.

S. Ackermann, J. Cherry, 'Richard II, John Holland and Three Medieval Quadrants', Annals of Science 56 (1999), pp. 3-23

F.A.B. Ward, Catalogue of European scientif (London, The British Museum Press, 1981)

S. Ackermann and J. Cherry, 'Richard II, John Holland and three medieval quadrants', Annals of Science, 56 (1999), pp. 3-23