Kingdom.] RAILWAY AND MARINE MECHANISM. 219

North Areas A. B. 10 to 34 ;■ G. D. E. 1 to 10, & 19 to 33 ; F. 1 to 32 ; G. II. 1 to 13, & 19 to 26.

of the evaporating liquid, and absorbs vapour at firstfrom the cooler and, by degrees, from the hotter endthereof. It then passes under the metallic bottom of thepan, and in proceeding towards the cooler end, the vapourwhich it contains is condensed, and yields its latent heatagain to the evaporating liquid. Heat is continuallysupplied at the hotter end, and is abstracted at thecooler end, where the cold liquid enters the. apparatus.The circulating current is divided into the principal cur-rent, which traverses the whole length of the apparatus,and into secondary currents, which return at interme-diate points, and are essential to the economical workingof the system. The fire burns under a boiler, whichsupplies a steam chamber at the hottest end. of the appa-ratus, and proceeds through flues traversing, the evapo-rating current in its progress towards the. chimney. Bythis means the evaporating current is superheatedthroughout its course to a temperature exceeding thatof the liquid by about 15 per cent, and its evaporatingpower is greatly increased.

The regenerative evaporator has been found to saveabout three-fourths of the fuel usually required to evapo-rate liquids. It has been applied on a large scale to theevaporation of brine, producing six tons of salt for everyton of fuel from a concentrated solution, instead of Iftons, which are usually obtained from a ton of fuel.

48 Bunnett, Joseph, & Co., 26 Lombard Street , City ,

and Deptford, Kent— Inventors, Patentees, and*Manufacturers.

Patent concentric reciprocating steam-engine for highor low pressure. The steam is worked expansively with-out gear or tappets. This direct-acting engine requiresneither guides nor parallel motion; it is compact, andadapted for stationary, locomotive, or marine purposes.

49 Collinge, Charles, & Co., 65 Bridge Road ,

Lambeth— Designers and Manufacturers.

Improved portable direct-acting high-pressure steam-engine of 5-horse power.

52 Rennie, George & Sir John, 6 Holland Street ,Blaclcfriars —Manufacturers and Licensees.

Working model of Bishopp’s patent disc engine of 40-horse pow er, fitted as auxiliary power to drive a screwpropeller, in a model of part of the hull of a merchant vesselof 300 tons. One-fifth the full size. Engine 2-horse power.

Disc engines have been used in factories, mills, &c.,for several years past, and they may be employed to drivethe screw-propeller in steam-vessels by direct action.The disc engine acts with a uniform force in a directiontangential to the crank throughout the revolution, with-out any rotary motion taking place within the cylinder;although such an engine be only half the bulk andweight of the engines at present applied to the screw-propeller, yet at the same velocity of the piston it makesthree times as many revolutions in a given time as otherengines. The disc engines on this construction are saidto be equal to the best engines in economy of fuel; andare, on this account, better adapted to vessels, as expan-sion can be carried to a great extent without strainingeither the frames or the vessel.

Model of II.M. steamer “ Samson’s” engines.—Powerot engines, 467-horse power; burthen in tons, 1,299;

To?* act * on weight of engines, 12 cwt. per horse-power.

Model of H.M, steamer “Bulldog ’s” engines.—Powerot engines, 500-horse power; weight of engines, 12 cwt.per horse-power.

Model, of a pair of marine engines, with four cylindersoi the joint power of 800 horse, proposed for transatlanticsteamers.

Models of paddle-wheels. Common paddle-wheel. Mo-difications of the common paddle-wheel on Mr. Rennie’spatent principle.

Model of a vessel fitted with patent paddle-wheels.

[In the direct-action marine-engine, circular motion iscommunicated to the paddle-shaft immediately from thepiston-rod, without the intervention of side levers, &c.;this arrangement saves space,weight, and friction.—S. C.]

53 Green, E., Plmnix Foundry, Wakefield —Inventorand Manufacturer.

Patent fuel economiser, applicable to steam-boilers, forheating the feed-water with the spare heat from the boilerflues.

An apparatus for supplying rooms and buildings withpure warm air.

56 Watkins & Hill, 5 Charing Cross —Manufacturers.

1. Sectional model, to illustrate the construction of acondensing steam-engine. One face showing the whole ofthe valves and pumps moving at their exact times, andthe other presenting an outside view of the engine.

2. Sectional model of a condensing steam-engine, withsection of the boiler and furnace. These models are con-structed in metal for use in tropical climates.

3. Sectional model to illustrate the construction of thelocomotive steam-engine. One face showing the forma-tion of the tubular boiler, and the action of the variousworking portions, and the other presenting the exteriorappearance of the engine.

4. Improved - mercurial barometrical steam vacuumgauge, combined on the same metal frame and scale, withan atmospheric barometer, to give an accurate comparisonof the vacuum and atmospheric pressure.

5. Sectional model to illustrate the construction of themarine steam-engine, without the boiler. One face showingthe action of the pumps and valves, the other presenting

.the exterior appearance of the engine.

57 Fitz Maurice, The Hon. Wm. Ed., Hamilton

Lodge, Prince’$ Gate— Inventor.

Patent rotatory steam-engine; stated to be light, simple,and cheap in construction, and not liable to get out oforder; for driving the screw or other power it acts withoutrequiring gearing of any kind. It is free from vibration,being its own fly-wheel.

[The superiority of one piece of mechanism overanother, designed to produce the same effect, depends noton any saving of power, or on any increased mechanicaladvantage, but on the adaptation of the construction tolessen friction, to prevent straining, to preserve the elas-ticity of some parts, and to secure the rigidity of others ;as also on the economy of space and material.—J. B.]

Model of a patent steam-engine, illustrating a newmethod of converting rectilinear into rotatory motion,by the Rev. J. Booth, F.R.S. Constructed by J. Aspinall,London .

Fig. 1.

This model (fig. 1) illustrates a new method of convert-ing rectilinear into rotatory motion. It is a practical appli-cation of the geometrical principle, that if the extremitiesof a given straight line in motion always rest upon two fixedstraight lines, at right angles to each other, the middle