overgenomen uit Spon's Dictionary of Engineering, Div. VI, pp.2237-2239, edited by Oliver Byrne and published by E.& F.N. Spon, London (1873)
Vertical section
To avoid upright tubes and horizontal tube plates, the heating surface of the boiler A is arranged in cones. The first cone or fire-box is exposed to the direct radiation of the fire, after which the heat passes through the opening E nearly opposite the fire-door into the space between the second and third cones, where it is absorbed by the water-spaces on either side, and passes round to the funnel F opposite. In this way, a sufficient heating surface is obtained without any horizontal surfaces in the boiler for deposit of silt to accumulate upon.
The two angles or bottoms of the water-spaces are below the direct action of the fire, and are connected by pipes G to allow for circulation of the water, and provided with plugs and cocks for cleaning. The water-tank H is placed under the boiler, this position serving to heat the feed-water and to prevent the cast iron bed-plate B from danger of fracture by the heat of the fire.