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 CHAP. XVIII. EARLY IRON BRIDGs0R 409 



instances of this kind of bridge was that erected over 

 Water Street, Manchester, in 1829 ; after which, cast- 

 iron girders, with their lower webs considerably larger 

 than their upper, were ordinarily employed where the 

 span was moderate ; and wrought-iron tie rods below 

 were added to give increased strength where the span 

 was greater. 



The next step was the contrivance of arched beams or 

 bowstring girders, firmly held together by horizontal 

 ties to resist the thrust, instead of abutments. Numerous 

 excellent specimens of this description of bridge were 

 erected by Robert Stephenson on the original London 

 and Birmingham Railway ; but by far the grandest 

 work of the kind perfect as a specimen of modern 

 constructive skill was the High Level Bridge, which 

 we owe to the genius of the same engineer. 



The problem was, to throw a railway bridge across the 

 deep ravine which lies between the towns of Newcastle 

 and Gateshead, at the bottom of which flows the navi- 

 gable river Tyne. Along and up the sides of the valley 

 on the Newcastle bank especially run streets of old- 

 fashioned houses, clustered together in the strange forms 

 peculiar to the older cities. The ravine is . of great 

 depth so deep and so gloomy-looking towards dusk, 

 that local tradition records that when the Duke of Cum- 

 berland arrived late in the evening, at the brow of the 

 hill overlooking the Tyne, on his way to Culloden, he 

 exclaimed to his attendants, on looking down into the 

 black gorge before him, " For God's sake, don't think of 

 taking me down that coal-pit at this time of night ! " 

 The road down the Gateshead High Street is almost 

 as steep as the roof of a house, and up the Newcastle 

 Side, as the street there is called, it is little better. 

 During many centuries the traffic north and south passed 

 along this dangerous and difficult route, over the old 

 bridge which crosses the river in the bottom of the val- 

 ley. For some thirty years the Newcastle Corporation 



