Scale: not calculated. Barrel from a fascinating model acquired from the Museum of Artillery in the Rotunda, Woolwich, London. The 1906 edition of the Rotunda Museum catalogue, lists this item as ’A steam boat with two drums on each side, over which pass endless bands to which are attached floats. By Capt Aytoun, R.A. About 1820’.

It is an ingenious idea from the earliest days of steam technology and, interestingly, it dates from the founding of the Museum of Artillery itself, the nucleus of which was a collection of design models made to demonstrate new ideas and principles of Colonel Sir William Congreve. Congreve, at the time, was the Superintendent of Military Machines at Woolwich and he would doubtless have been enthusiastic about models such as this one and been keen to add it to his fledgling museum.

It is a very heavy model for its size and, when the thin plywood deck is removed, one can see why. There are two clockwork mechanisms - one fore, one aft - used for turning the drums. The key for winding them up is inserted through apertures in the hull, one on the port-bow side, the other on the starboard quarter. There are four paddles on each belt and, in the centre of the hold there are two removable heavy, solid wooden barrels that are possibly there to provide ballast. It would be nice to think that it was made as an early test-tank model and one wonders how it would have performed in the water.