Arms and armour are rarely associated with art. However, they were influenced by the same design sources as other art forms including architecture, sculpture, goldsmiths' work, stained glass and ceramics. These sources had to be adapted to awkward shaped devices required to perform complicated technical functions. Armour and weapons were collected as works of art as much as military tools.

This spanner and wheel-lock are the mechanism that once enabled a gun to fire. The jaws of the lock clamped a piece of flint or a piece or pyrites designed to rub against the rough edge of the wheel projecting into the pan. The wheel was revolved at speed by a tightly coiled spring wound by the spanner and released when the gun's trigger was pulled causing sparks to ignite the gunpowder in the breech.

Sketches for wheel-locks were made by Leonardo da Vinci but their first common use was in Germany in around 1520 and they continued in use until the late seventeenth century. They were the first devices to fire guns mechanically and accelerated the development of firearms by negating the need for long and dangerous 'match' cords which had to be kept dry.

As technical devices they attracted princely collectors. Many are finely chiselled and engraved as works of art, some even on their insides, to be taken apart and reassembled at pleasure. Wheel-locks were expensive, however, and most ordinary gunners were equipped with the older style match-locks until well into the seventeenth century.