196 VEGETABLE SUBSTANCES. 



bridge at Battersea is not much better, though it be 

 a comparatively recent erection. Fulham bridge was 

 completed in 1729 ; and that at Battersea in 1772 ; 

 and though the piers of the latter do not obstruct the 

 navigation quite so absurdlj' as those at Fulham, in 

 consequence of their being parallel to the current, 

 while those at Fulham stand obliciuely to it, the one 

 bridge is just as totally destitute of taste in its ap- 

 pearance, and science in its construction, as the 

 other, though it was erected in a comparatively ad- 

 vanced age, and under the sanction of an act of par- 

 liament. There is, in fact, little more knowledge of 

 the principles of carpentry, even the very simplest 

 ones, displayed in those bridges, than in the bridges 

 which the beavers are said to build in the vicinity of 

 Hudson's Bay, by cutting a tree with their teeth, 

 and contriving that it shall fall across the river. 

 That they should be tolerated so near a metropolis 

 in which there are stone bridges like the Waterloo 

 and the New London, and iron ones like the South- 

 wark and Vauxhall, would seem a little singular, if it 

 were not borne in mind that they are ])rivate property. 

 Timber is not only useful in forming the materials 

 of bridges, where the circumstances or the expense 

 will not admit of stone or iron, but it is essential for 

 the construction of stone bridges themselves. With 

 regard to them, it answers three purposes. First, 

 the formation of coffer-dams, by means of which the 

 foundations of the piers, or rather the places where 

 they are to be founded, are cleared of water ; second- 

 ly, when the soil is not of sufficient consistency to 

 afford a firm foundation, piles of timber are driven 

 into it ; and, thirdly, centerings of timber are con- 

 structed, upon which the whole weight of the arch can 

 be borne, until the key-stones are driven into their 

 places, which centerings can then be removed with 

 comparatively little labour. 



