200 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[June, 



H-liich heat will lie transmitted and steam can be produced; the 

 iiuictcer ani more povverfiil the transmission of caloric may be, the 

 less extent of surface «ill he reciuired: the pressure in the boiler 

 H'ill correspond with, or be in proportion to, the temperature of the 

 water; and this pressure will increase or diminish as the tempera- 

 ture of the water increases or diminishes. Now, the rays of heat 

 beinjr diveri,'ent, and the temperature of the s-i'^es, which i)ass oif 

 by the orifice of the chimney, beinj,' in direct ])roportion to the in- 

 tensity of the fire, or equal to that of the steam contained in the 

 boiler, we may conclude that theheatinfr surface of the chamber p, 

 and flue f, is more than sufTR-ient to take up and transmit the 

 lar^'cst quantity of caloric which can be fjiven out by the fire; and 

 that the speed w itli which this beatinfr surface transmits tiie caloric 

 to the water is equal to the rapidity witli which caloric is given off 

 from the incandescent fuel; and further, that the practice of using 

 the large extent of heating surface, which it has always hitherto 

 been considered necessary to employ, in constructing steim-boilers 

 or generators, is not derixed from a principle or natural law, but 

 merely from a rule laid down by constructors and engineers, and 

 admitted a priori." 



'i'he i)atentee claims the combination, with a vertical flue, of a 

 conical fire-place or enlarged heating chamber at the lower part of 

 the same, or any mere modification thereof; whereby the intensity 

 of the fire in the fire-place may be greatly increased' by a portion 

 of the caloric given out from the incandescent fuel being reflected 

 back upon the fuel or combustible gases in the enlarged heating- 

 chamber; and which fuel and combustible gases are thereby more 

 effectually and economically consumed than in steam-boiler fur- 

 naces, with a more extended heating surface and less intensity of 

 heat. 



RAILWAY AFHEELS. 



Enoch Chambers, of Birmingham, smith, for ^'■improvements in 

 the manufacture of wheels." — Granted November 10, 1849; Enrolled 

 Way 10, 18.50. 



AV^heels made according to this invention are each first made up 

 into two halves, each halfconsisting of one half of the ring or felloe, 

 one half the spokes, and one-half of the nave, all of wrought-iron, 

 and the parts of a wheel are made in the following manner: — For 

 each half of the nave a block or plate of iron is forged in a cylin- 

 drical exterior frame, with a flange or ])roiection all round, and 

 this flange or projection is to be drawn out by forging, so as to form 

 projecting pieces at those parts in the circumference wliere the 

 spokes are to be welded on. In the wheel shown in the drawings 

 which accompany the specification there are eiglit spokes, four on 

 each half-wheel, and in all cases this construction of wheel requires 

 to have an even number of sjiokes, half being afiixed or welded to 

 one-half of the nave, and the other half of the spokes being fixed to 

 the other half of the nave, and the spokes being )>laced in such 

 relative positions that those of the one half shall come into the 

 spaces between those of the other half. The projection or flange 

 being thus drawn out or forged at intervals on each half of the 

 nave of an intended wheel, so as to produce pnqier projections for 

 the purpose of receiving the spokes; the spokes are to be welded 

 on, each spoke having a portion of the ring or felloe of the wlieel 

 forged thereon, the alternate jiortions of the felloe or ring beimr 

 0.1 the two half naves respectively; so that when the two are 

 brought together, and the inner surfaces of the two half naves are 

 brought together, they w ill form the wheel. The two half naves 

 are to be Iirougbt to a welding heat, and being jilaced one on the 

 other in the position above described, are to be welded together by 

 a suitable hammer or press. The patentee prefers to use a steam 

 hammer for this jiurpose; and the parts of the felloe or ring of the 

 wheel where they come together are also to be welded, and the tyre 

 is to be shrunk on, and the wheel completed. The centre of the 

 nave of the wheel is to be cut or turned out, and made suitable to 

 receive the axle-tree, as shown, and as is well understood. 

 Instead of welding the spokes and part of the felloe to the half 

 naves before welding the half naves together, the spokes and parts 

 of the felloe may be welded on afterwards, but the former method is 

 preferred. In tiie preceding descrijition special reference is had to 

 railway wheels, but the same method of construction is ecpially 

 applicable to wheels for common- road carriages and wagons. 



Claims. - 1. The manufacture of wiieels by first making the nave 

 in two parts (divided vertically) each having half the number of 

 spokes, with a portion of the felloe attached to each spoke, and 

 tiien welding together, the said two half naves, after which the 

 tyre is shrunk on as usual. — 2. The making of wrought iron naves 

 with tivo flanges, each to receive, and have welded thereto^ one 

 lialf of the spokes of which a wheel is to be compj»ed. 



SIEMENSS REGENERATIVE CONDENSER. 



On Siemem's Patent Regenerative Condenser. By .Mr. C. W. 

 SiKMENS, of Birmingham. (Paper read at the Society of Arts, 

 May 15th; Robert Stephenson. Esq., M.P., V.P., in the Chair.) 



The paper commences with a historical sketch of the Condenser 

 of the Steam-engine, from the invention of Savery, in which a 

 single vessel served the triple pur])Ose of steam-cylinder, condenser, 

 and water-pump, to James W^itt's injection condenser. Horn- 

 blower ])roposed a surface-condenser, which was, however, deficient 

 in extent of cooling surface, and therefore failed, as have many 

 others invented since; the most prominent being that of Mr. 

 Samuel Hall, in which the steam was jiassed through tubes im- 

 mersed in a stre:im of cold ivater. This condenser has the serious 

 drawbacks of weight, costliness, and difficulty of getting rid of 

 the calcareous deposits from the condensed steam. 



HI St. pn^ 



-di> 



-^.^f ^ 1^ 



Three years ago Mr. Siemens invented his surface-condenser for 

 a situation where economy of space and material was essential. It 

 consists of a number of copper plates ^^-inch in thickness, 4^ 

 inches broad, and 2 feet long, which are piled together with two 

 longitudinal flattened wires of the same metal intervening between 

 the adjacent plates, the whole pile being screwed up tight together 

 between the sides of a rectangular cast-iron vessel, constituting 

 the body of the condenser. The ends of the plates project through 

 the top and bottom of the vessel, and are planed flush with its ex- 

 terior surfaces. The joints are at top and bottom, secured by 

 means of india-rubber rings, screweil down under small cast-iron 

 frames, and which yield to the difference in expansiim of the two 

 metals. The flattened wires are laid parallel, and about three 

 inches apart, and form, with the plates, a large number of narrow 

 passages, through which the cold condensing water flows in an up- 

 ward direction without entering the vacuous space of the con- 

 denser, into which the ends of the plates outside the flattened 

 wires — forming the condensing surfaces — project. The heat of the 

 steam is thus passed through the plates, from their edges towards 

 the centre, to the condensing water, — the limit to its eflicicncy 

 being the conducting power of the metal. 



