1848. 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



343 



is the adaptation to direct-acting steam-engines of high-pressure 

 and expansion cylinders, which are placed side hy side upon the 

 sole plate, the two piston-rods of these being attached above to a 

 cross-head, common to both ; from the centre of the cross-head 

 a connecting-rod passes down between the two cylinders to a 

 crank placed upon the shaft below. To preserve the parallelism 

 of the piston-rods, a system of levers is placed above, in connec- 

 tion witli the cross-head. These levers and rods liave also the 

 effect of equalising the strain of the tvf o pistons. Another part 

 of tlie invention consists in the adaptation to double-acting air- 

 pumps of slide-valves instead of the clack-valves, the slide-valves 

 being worked by an eccentric or crank in the manner of the 

 usual slide-valve of steam-cylinders. Expansive slide-valves are 

 formed by placing on the cylinder-face loose blocks, which are 

 connected to the valve itself by means of two rods, one on each 

 side, upon which are placed nuts for the purpose of adjusting the 

 distance of the blocks from the valve ; and thus, by increasing or 

 diminishing that distance, to vary the expansion of the steam in 

 the cylinder. A further improvement consists in the construction 

 of safety-valves for steam-boilers, by combining with the ordinary 

 conical safety-valve, a piston within a cylinder so arranged that 

 whenever, from its ceasing to act, the pressure of steam in the 

 boiler increases beyond the required amount, the rise of the piston 

 will open the valve and thus relieve the pressure. 



FURNACES AND BLOWING MACHINES. 



George Lloyd, of Stepney, Middlesex, ii-on-founder, for " cer- 

 tain improvements in furnaces and bloicing machines, and in engines 

 and machinery far driving the same ; which improvements are also 

 applicable to other purposes where motive power is required." — 

 Granted March 8; Enrolled September 8, 1848. 



This is a multifarious specification, comprising so many separate 

 " improvements," that it is difficult, without occupying more space 

 than we are willing to bestow, to give any description of the whole; 

 we must therefore confine our notice to a few of the leading 

 points. The principal part of the invention relates to furnaces 

 for heating steam-boilers. The furnace cliamher does not pass 

 under the boiler, but is at the extreme end. The fire-bars are 

 placed in a vertical position, about the same situation as usually 

 occupied by the fire-doors ; while the fuel is inserted at a hopper- 

 mouth at the end of the boiler, which, in this case, is represented 

 as being flat, with the fuel chamber extending partly up the end. 

 This chamber is about the usual width of furnaces ; but in its 

 length, it is confined to about the usual depth of fuel by means of a 

 number of fire-brick lumps, extending from the hearth to the 

 bottom of the boiler, and placed so as to present their edges to the 

 fuel in the manner of bars. The fuel being ignited, is piled within 

 the chamber till quite full, the only covering being the uncon- 

 sumed fuel which extends in the hopper-mouth above the bars. 

 The products of combustion pass between the fire-lumps, in con- 

 tact with the bottom of the boiler, and break into a chamber im- 

 mediately in front of the bridge, where a series of pipes are placed 

 for the admission of air. The great heat attained by the fire- 

 lumps, imparts a sufficient degree of heat to the gaseous products 

 to cause them to flash into flame on being mixed with a due pro- 

 portion of atmospheric air. This flame is conducted over the 

 bridge and through the flues in the ordinary manner. In the 

 construction of the blowing machines, the blades are tapered 

 towards the points, and are placed at angles of 60 degrees back- 

 wards, by which means the inventor proposes to overcome the dis- 

 advantage which blowing machines usually possess of waste of 

 power, by the fans striking the air within the case that is not ex- 

 pelled. The blades are confined at the sides by discs of metal ex- 

 tending to the point of the blade, and having an opening in the 

 centre, of the same area as the openings in tlie sides of the case. 

 The air driven off at the periphery is limited by the entire area 

 between tlie blades being equal to the area of the side inletsj and 

 at the same time attains a superior blast withless power,without that 

 disagreeable beating noise, consequent on a rapid motion being 

 given to the ordinary fanner. Another blowing machine, de- 

 scribed in the specification, consists of a series of bellows placed 

 within an octagonal case, each of the eight sides forming a base for 

 one bellows. The other boards of the bellows are placed in a 

 radial line, each of the upper or moving boards being attached to 

 a crank in the centre of the case by a suitable connecting-rod ; 

 this crank being actuated by a shaft passing out at the sides of 

 the case, which is closed quite air-tight. On motion being given 

 to the shaft, the bellows wiU be successively acted upon, as the 

 crank performs its revolution. The air entering from the outside 



by inlet valves, when the bellows are expanded and discharged 

 inside the case, when collapsed by the motion of the crank, a 

 uniform pressure of air is thus kept up, which may be conducted 

 by suitable pipes or channels from the casing to the point required. 

 The following claims of the patentee set forth the various inven- 

 tions included in this specification : — First, the construction of a 

 steam-boiler furnace, in so far as regards the combination of ver- 

 tical fire-bars made in two pieces, together with vertical fire-clay 

 lumps behind the fuel-chamber, and vertical air-tubes behind the 

 fire-lumps. Secondly, the employment in furnaces of every de- 

 scription of fire-bars made in two pieces. Thirdly, the mode of 

 applying the vajiours arising from the chimneys of cupolas for the 

 heating of boilers. Fourthly, the construction and arrangement 

 of tlie fan blowing-machine, in so far as regards the employment 

 of an inner casing with openings of small area in its periphery. 

 Fifthly, the general arrangement and combination of parts con- 

 stituting the bellows blowing-machine. Sixthly, improvements in 

 rotary steam-engines, in so far as regards the employment of two 

 or more chambers, and two or more sets of arms and steam-jets or 

 apertures in such arms of successively increasing area. Seventhly, 

 an improved spindle or shaft-bearing in which the end or journal 

 of the shaft works in a collar or socket of plumbago. Lastly, 

 the construction of strap-riggers of a combination of iron and 

 gutta percha. 



ZINC ORES. 



Charles Andre Felix Rochaz, of Paris, France, merchant, 

 for '■^certain improvements in treating zinc ores, and in manufac- 

 turing oxide of zinc." — Granted December 22, 1847; Enrolled June 

 22, 1848. [Reported in Newton's London Journal.^ 



This invention consists, firstly, in improvements in the treat- 

 ment of zinc ores; and, secondly, in improvements in manufac- 

 turing oxide of zinc. 



First, as regards the treatment of the ores of zinc : — This pro- 

 cess has usually been effected by first converting them into the 

 state of oxide, by roasting or calcination, and afterwards reducin;,- 

 and distilling the oxides, by mixing them with coal, and submitting 

 them to great heat, in close vessels or retorts. This mode of ope- 

 ration is attended with great disadvantages, for, besides occasion- 

 ing great consumption of fuel, and rapid destruction of the re- 

 torts, the product obtained is by no means proportionate to the 

 richness of the ore. 



By this improved process the employment of retorts is entirely 

 dispensed with, and the fuel and labour are greatly economised ; 

 the operation is also completely independent of the skill of the 

 workman or attendant ; and, lastly, the loss of metal incidental 

 to the ordinary method is prevented. Besides these advantages, 

 the patentee observes, that ores of lead and zinc may both be ope- 

 rated upon at once by his improved method. 



inrj!? 



Fig. I. 



The principal feature of the invention consists in the reduction 

 of roasted blend-ore (native sulphuret of zinc), and of the car- 

 bonates, oxides, or silicates of zinc, and also of the sulphurets and 

 oxides of lead, by the action of the reducing gases of a blast fur- 



