IMPROVEMENTS IN. STEAM ENGINES, 93 



whether simple water and steam, would have the same effect; 

 and upon the hint of Chancellor Livingston, our present Am- 

 bassador in France, Messrs. Roosevelt Smallman and Haudin- 

 ger contrived the wooden boiler, which has been used for all 

 the engines in New York and Philadelphia; and not without 

 its great, though only temporary, advantages. The construc- 

 tion of the wooden boiler, will be best understood, by refer- 

 ence to the plan and section of the new boiler of the engine 

 in Center-square, Philadelphia, which is by far the best of 

 those which have been made. It is in fact only a wooden 

 chest containing the water, in which a furnace is contrived, 

 of which the flues wind several times through the water, 

 before they discharge themselves into the chimney. 



In the plan and section, Plate II, Fig. 1, 2, 3, 4, A is the fur- 

 nace, B B B, are upright cylinders, called heaters, among 

 which the fire passes, heating the water within them, and 

 which, at the same time, support the roof the fire-bed, or 

 lower passage of the flame to the flues. C, is the take-up, or 

 passage from the fire-bed to the flues. D the upper flue through 

 which the fire passes from the take-up to the register E, when 

 it enters into the chimney. 



This boiler differs from the others, in the addition of the 

 upright cvlinders of the fire-bed, and in the elliptical form of 

 its flues. The merits of this boiler are — that as the wood, in 

 which the water is contained, is a very slow conductor of heat, 

 a great saving of fuel is thereby effected; especially, as an op- 

 portunity is afforded, by means of the cylindrical heaters and 

 of the length of the flue, to expose a very large surface of 

 iron containing water to the action of the fire. An idea of 

 of this saving may be formed, by the quantity of coal consu- 

 med by the engine in Center-square, which is a double 

 steam-engine, the diameter of whose cylinder is 32 inches. 

 The power of this engine is calculated to answer the future, 

 as well as to supply the present wants of the city ; it is there- 

 fore kept irregularly at work, filling, alternately, the elevated 

 reservoir, and stopping during the time which is occupied by 

 the discharge of the water into the city. It may, however, be 

 fairly rated to go at the rate of 12 strokes, of 6 feet, per 



