A brass mortar, named after the Dutch engineer who invented it.
It is the smallest piece of ordnance in the service, having a bore of 4-1/2 inches diameter, a length of 1 foot, and a weight of 3/4 cwt. They throw their 12-pounder shells with much precision to moderate distances, and being fixed to wooden beds, are very handy for ships' gangways, launches, &c., afloat, and for advanced trenches, the attack of stockades, &c., ashore.