THE

London

JOURNAL AND REPERTORY

OF

Arts, Sciences, and Manufactures.

CONJOINED SERIES.

No. LXVII.

Recent Patents.

To JAMES DREDGE, of the parish of Walcot, in the city of Bath, and county of Somerset, brewer, for his invention of certain improvements in the construction of suspension chains for bridges, viaducts, aqueducts, and other purposes, and in the construction of such bridges, ciaducts, or aqueducts.-[Sealed 17th June, 1836.]

THESE improvements in the construction of suspension chains for bridges and other erections to be supported on the principles of suspension, and in the construction of such bridges and other suspended erections, have for their object, first, a means of affording greater strength and stability than has been obtained by any of the varied constructions of suspension bridges, piers, or other erections of that kind, which have been here. tofore formed of corresponding magnitude and ex

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tent; and, secondly, the economy of materials and labour required to be expended in such erections.

These objects are effected in the first instance, by so arranging and connecting a series of parallel links to constitute the chains, that the chain may diminish in breadth, and, consequently, in weight, as it recedes from the point or points of suspension; secondly, in applying such chains to the purposes of constructing suspension bridges and other similar erections, in connexion with inclined suspension rods or bars instead of the usual perpendicular suspension rods or bars, by means of which I am enabled so to connect the longitudinal bearings of the horizontal platform or roadway to the hanging chains, that the weight or principal leverage of the erection may be removed from the centre, and be sustained by the stronger parts of the chains increasing towards the abutments; thirdly, in the employment of transverse tie-beams of a peculiar construction for confining the longitudinal bearings of the horizontal platform or roadway; and, fourthly, the adaptation of a ball and socket bearing to the inclined suspension bars or rods, by means of which, the level or proper position of the platform may be readily adjusted.

In Plate I., fig. 1, represents, upon a large scale, a portion of chains formed by sets of links placed side by side in parallel series a, a, a, a, a, a; b, b, b, b, b; c, c, c, c; &c., connected together by transverse bolts z, z, z, the links of each of which series diminish in number as they recede from the piers or points of suspension. Fig. 2, represents a side elevation of a suspension bridge constructed with chains of this description, and inclined suspension rods or bars m, m, m ;