21 

 ARCHITECTURE, BRIDGES, &c. 



90. Timber Bridge — 200 feet span, which is the largest span 

 in timber that has been attempted in this country. — Each curved 

 under bearer forms an abutment for each pair of struts which 

 support the upper bearers, both the upper and under bearers 

 are so connected together by the struts and suspending pieces, 

 that the framing forms a solid rib, upon which the joists for 

 supporting the roadway are sustained, and the whole weight 

 of the bridge itself and the weights passing along it, ultimately 

 rest upon the abutments. This bridge is intended for turnpike- 

 road traffic, but the principle may be applied to any other kind 

 of traffic, such as railway traffic, with heavy locomotive engines 

 passing at rapid rates. A bridge of two arches, each similar to 

 the above, is now about to be erected over the Tweed at 

 Norham. — J. Blackmore, Esq. engineer, Newcastle. 



91. Model of Piers for a Suspension Bridge, By J. Green, 

 Architect and Engineer. — Proposed to be erected across the 

 mouth of the Tyne, in 1827, at the height of 110 feet above 

 high water level, and 1,000 feet span. 



92. Model of a Suspension Bridge, in which the suspending 

 rods are inclined instead of being vertical as in the usual con- 

 struction. — By James Dredge, Esq. Bath. 



93. Model of a Monument— erected in the Westgate Cerhetry, 

 Newcastle, by Benjamin Green, Architect. 



94. Model of an Arch— 120 feet span, by John and Benjamin 

 Green, architects, being part of a bridge of five arches, designed 

 in 1834, which obtained the premium offered by the Newcastle and 

 Carlisle Railway Company at that time, for crossing the River 

 Tyne above Scotswood. This arch is on the same principle as 

 the immense viaducts now in progress on the Newcastle and 

 North Shields Railway. 



95. Model of a Timber Arch, on a new construction. By 

 Messrs. Green, Architects.— In this arch the ribs are put together 

 with Dantzic deals, in lengths of from 21 feet to 45 feet, 11 

 inches broad, and 3^ inches thick, fixed together with oak tree- 

 nails. The experiments tried have sufficiently proved the strength 



