This device for testing gunpowder was made in Avignon, France and dates to the 17th or early 18th century.

The amount of powder charge needed to pour down the muzzle of a gun depended on the strength of the powder, as well as the barrel length and bullet size. Testers tended to use the same mechanisms as the guns of the day, so this example with a nicely turned-wood handle and iron ratchet wheel, probably dates to the wheel-lock era. Samples of powder were ignited in the touch-hole and forced the wheel to rotate by means of a spring. Originally the wheel would have been marked with graduations from which the strength of the powder could be calculated.