Pocket azimuth sundial

Known as a pocket azimuth sundial, this instrument would have been used as a portable solar watch. It was created in Dieppe, France in around 1670 by Charles Bloud, and has been in RAMM’s collection since 1873, having been donated by Rev W Hayne Dinham.

Pocket sundials became a particularly popular device for timekeeping between the 15th and 19th centuries. With the growth of mercantile societies in the late medieval and early modern world, sundials had both functional and decorative purposes. As well as helping to keep busy people on schedule, these objects had symbolic value, projecting the tastes and wealth of their owners.

These fashionable items enabled craftsmen such as Bloud to express their artistic skills and ingenuity in design. On this example, delicate silver dials have been embedded within an ivory case, engraved with swirling floral decoration.

The magnetic azimuth sundials were invented by Bloud were not only portable, but also designed to work at multiple latitudes. As universal sundials, these instruments were intended to accommodate the needs of merchants, pilgrims and other long-distance travellers. The principle by which Bloud’s sundials worked is based on the magnetic variation of the area around Dieppe which existed for only a short period in the seventeenth century, beginning about 1666.

This sundial consists of an equatorial dial with a detachable gnomon, stored in a drawer at the side. The owner could determine the time by placing the gnomon into position, then orienting the sun's shadow along a specified line on the sundial. With the help of an in-built compass, the hour could then be read. This sundial could also inform its owner of the date, month and phases of the moon, as well as the time.