At the beginning of the last century only three bridges spanned the Thames in its course through London, and of these two were scarcely fifty years old; but before the century closed there were no less than thirteen bridges across the river between Battersea and the Pool. The three old bridges have been rebuilt, and even some of the later ones have been reconstructed, whilst one has been removed bodily, and now spans the gorge of the Avon at Bristol. Of all these bridges unfortunately only two are constructed wholly of stone, and can lay claim to any architectural merit; and even one of these two has recently had the happy effect of its graceful arches destroyed by the addition of overhanging pathways. Of the rest, some are frankly utilitarian--mere iron girder railway bridges, with no attempt at decoration beyond gilding the rivets--whilst the others have their iron arches and construction disguised with coarse and meaningless ornaments. One only of the iron bridges is in anyway worthy of its position; in its perfect simplicity and the bold spans of its three arches, Southwark Bridge bears comparison with the best in Europe, but the gradients and approaches are so inconvenient that it is even now threatened with reconstruction. [Illustration: SIR JOHN EVELYN'S PLAN FOR REBUILDING LONDON AFTER THE GREAT FIRE.] Exactly when the first bridge was built across the Thames at London we can only surmise, for even tradition is silent on the subject, and we only know of the existence of one at an early date by very casual references, which, however, do not help us to realise the character of the work. Though no evidence remains of a Roman bridge, it seems unlikely, having regard to the importance of London, and to the fact that the great roads from the south coast converged on a point opposite to it, on the other side of the river, that they should have been left to end there without a bridge to carry them over. The difficulties of building across a great tidal river had not prevented the Romans from bridging the Medway at Rochester, as remains actually discovered have proved; and if no evidences of Roman work were actually met with in the rebuilding of London Bridge or the removal of the old one, this may be due to the fact that each successive bridge--and there have been at least three within historical times--was built some distance further up the stream than its predecessor.