AN EPROUVETTE – OR POWDER TESTER
ONE of the constant annoyances for any sportsman during the 18th and early 19th centuries was the variable consistency of the gunpowder that was sold for use in his sporting gun. To ensure that he had consistent and reliable powder was essential if the sportsman was going to be a successful shot, and particularly so if competing in shooting competitions on which money might be wagered.
How, therefore, could the 18th- and, indeed, the 19th-century sportsman ensure the consistency of his gunpowder and what was available to test it with? The essential piece of equipment to achieve this was an eprouvette, more commonly known as a powder tester or powder gauge. Although originally developed to test the quality of the gunpowder used by artillerymen, they rapidly became available from the early 18th century for sportsmen and gunsmiths to test the supply of powder, often before purchase.
These testers functioned in a range of different ways, including gravity, a pendulum or a friction wheel, all of which are represented in the Royal Armouries collection. This example, a small, English-made friction wheel tester, is of small flintlock boxlock type in brass with a plain walnut pistol grip that uses the resistance principle based on friction applied to a wheel by a spring working on the wheel’s edge. To carry out a test the user would load the short, 4mm barrel with a small quantity of the powder to be tested and then, ensuring that the anvil attached to the wheel is flush with the end of the barrel, fire it.
When fired off in the manner of any standard flintlock pistol the force of the explosion pushes against the face of the anvil that, in turn, as it is forced open, rotates the wheel against the pressure of a spring. The wheel stops rotating as the force of the explosion dissipates and a value can then be read off the side of the wheel. These values are usually just represented by numbers, often 1 to 10, but in the case of this example, 1 to 9. The idea being to get a consistent number each time, which in turn gives confidence in the gunpowder to be used.
This eprouvette, or powder tester, carries the name of William Taylor, a gunmaker working from premises in Market Place, Beverley, in Yorkshire. He established his business in 1813 and after his death in 1842 the business was carried on by his wife, Elizabeth, until she sold it in 1857. Powder testers like this would have been among the many items, other than guns, offered for sale by provincial gunmakers like Taylor, including crossbows, airguns, accessories and, most importantly, gunpowder.
This tester would not have been made by Taylor but was almost certainly made in Birmingham in about 1818 or so, with Taylor subsequently adding his name for sale.
The eprouvette can be viewed by appointment at the Royal Armouries Museum, Leeds, the national museum of arms and armour. Open Wednesday to Sunday, 10am to 5pm, or daily during school holidays. Prebooking essential. Tel 0113 220 1916; royalarmouries.org