230 Class 5.—MACHINES FOR DIRECT USE, INCLUDING CARRIAGES, [United

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

is increased according to difference of the capacity be-tween it and the last, which was in this case as 1 to 354'3.

Four such cylinders- have been cast at Bank QuayFoundry, and they are, perhaps, the most powerfulmachines ever constructed.—R. H.]

413 Howard, Ravenhill, & Co., King and Queen Iron

Works , Rotherhithe —Inventors, Patentees, andManufacturers.

Link of a suspension bridge chain, formed of eleven bars,to illustrate the method of rolling bars for suspensionbridges, and similar pui’poses.

This process produces the bars of the form required atone heat, and is intended to supersede the uncertain andinsecure method of welding on the heads; and to carrythe fibre of the iron in the proper direction around theeye to resist the strain of the coupling pins. The bars ex-

• hibited form a link of the chains in all respects similarto those manufactured for the suspension bridge over theDanube at Pesth . The tubes of the Conway and Bri-tannia bridges, the latter weighing 2,000 tons, and lifted100 feet, were safely raisedby chains made on this principle.

[With a force of about 10 tons per square inch of sec-tional area, the elasticity of wrought iron is wholly ex-cited, and in some cases surpassed. Engineers, therefore,do not subject it to this strain, even when the iron isperfect in the texture of all its parts; but as in the caseof chains with welded heads, the texture can never beperfect, a still larger margin must be left; probably thestrain permanently acting on it should not much exceed5 tons per square inch. If by any process of manufacturethese defects can be certainly removed, greater safetymay be gained by a less expenditure of metal.—S. C.]

414 Gossage, J., 71 Florence Road, Deptford —

Inventor.

Improved portable engine-pump, designed for the useof ships, particularly for men-of-war. It may be used fora fire-engine, watering-engine, and wash-deck pump. Itis available for all the purposes of a lift or force-pump;also, as an auxiliary to, or substitute for, any fixed pumpin use on board ships, in case of need, and can be used towet the ship’s sails, or worked in a boat to wash the ship’sside, and extinguish fire.

The principal peculiarities are, its portability and capa-city of working in less space, greater durability under

• action of sea-water, and its not being so liable to be in-

jured from accident, nor to get out of order; metallicvalves are used in lieu of leather, with vulcanized India-rubber discs between the piston caps, and its general con-struction is suited for all climates. It is not renderedinefficient by not being in constant use, or by being keptfree from water. _

415 Greatorex, Dan., 9 Dcsborough Terrace , HarrowRoad , Paddington —Inventor and Manufacturer.

Model (scale 1^ inch to a foot) of an improved hoist-ing machine, for raising or lowering goods; the machinecan be worked by hand or steam, and its whole operationrequires but one man. The principle is applicable todinner-lifts for hotels and mansions.

416 BellhoUSE, E. T., & Co., Eagle Foundry ,Manchester —Inventors.

Hydraulic press for packing cotton, or other materialin bales; worked by two hand-pumps; with illustrativedrawings.

Model of the exhibitors’ fire-proof hoist for mills andwarehouses. This plan prevents the rapid communica-tion of fire from one story to another, by the interpositionof fire-proof doors between each story; an arrangementis introduced which causes the doors to shut by theirown gravity, when the cradle is removed.

Model of the iron shell of a cottage.

Brick-pressing machine, with W. Percy’s self-lubri-cating piston.

Small hydraulic press, adapted for making experimentsin the compression of material.

417 Fairbairn, W., & Sons, Manchester —Inventorsand Manufacturers.

Patent tubular crane, manufactured by the exhibitors.

[The following observations on this crane are extractedfrom a paper contained in the Reports of the BritishAssociation, communicated by Sir David Brewster :—

“ These structures indicate some additional examples ofthe extension of the tubular system, and the many ad-vantages which may yet be derived from a judicious com-bination of wrought-iron plates, and a careful distributionof the material in all those constructions which requiresecurity, rigidity, and strength.

“The projection or radius of the jib of these cranes is32 feet 6 inches from the centre of the stem, and its height30 feet above the ground. It is entirely composed ofwrought-iron plates, firmly riveted together on the prin-ciple of the upper side being calculated to resist tension,and the under, or concave side, which embodies the cellularconstruction, to resist compression. The form is correctlythat of the prolonged vertebra? of the bird from which thismachine for raising weights takes its name; it is trulythe neck of the crane tapering from the point of the jib,where it is 2 feet deep by 18 inches wide to the level ofthe ground, where it is 5 feet deep and 3 feet 6 incheswide. From this point it again tapers to a depth of 18feet under the surface, where it terminates in a cast-ironshoe, which forms the toe on which it revolves. Thelower or concave side, which is calculated to resist com-pression, consists of plates forming three cells, and vary-ing in thickness in the ratio of the strain; as also theconvex top, which is formed of long plates chain-rivetedwith covers; but the sides are of uniform thickness,riveted with iron, and covering plates 4J inches wideover each joint. This arrangement of the parts anddistribution of the materials constitute the principalelements of strength in the crane. The form of the jib,and the point at which the load is suspended, is probablynot the most favourable for resisting pressure. It never-theless exhibits great powers of resistance; and its form,as well as the position, may safely be considered as acurved hollow beam having one end immoveably fixed atA, and the other end, C, the part to which the force isapplied. Viewing it in this light, the strengths are easilydetermined, and taking the experiments herein recorded,AdC'

we have by the formula W = —-—, a load of 63 tons,

the weight it would require to break the crane. With20 tons the ultimate deflection was 3 1 97 — • 64 of a per-manent set = 3 ■ 33 inches, the deflection of the jib due toa load of 20 tons. The following constitute the experi-ments made at Keyham Docks

“ Experiments made to ascertain the resisting powers ofa new wrought-iron tubular crane, erected at KeyhamDockyard, Devonport, November 8, 1850.

Weight ofCargo inTons.

2

3

4

5

6

7

89

10

Deflection at thepoint of the Jibin Indies.

•32•50* 65

•90 ( ^ tons suspended the

1*05 ] crane was turned completely

1 • 20 " l roun< ^» without any altera-^, 22 (_ tion in the deflection.

1*50

1*70

With this weight the crane was again turned round; the