Still, when another bridge was wanted over the Thames, at a busy spot, crowded with shipping and near the historic Tower of London, another kind of structure was adopted. What was it? CHAPTER V. THE TOWER BRIDGE. “Why should they not have a drawbridge?” “What! To draw up from each bank of the river?” “No, I did not mean that exactly. Could they not get piers farther in towards the centre of the stream, and let the drawbridge rise and fall from them?” “The river is too crowded for many piers.” “It is. But I cannot help thinking a drawbridge—a bascule bridge as the engineers call it—is the best solution of the difficulty.” “Well, a bridge is wanted sufficiently low to spring from the flat banks of the Thames for foot passengers and carriage traffic, and yet sufficiently high to permit tall ships to pass underneath.” “And apparently these two requirements are incompatible.” “Not altogether,” remarks a third speaker. “You are partly right in your idea of a drawbridge. That is Sir Horace Jones’s idea. And, further, there is literally to be a high and also a low-level bridge; for there are to be two levels—that is, two roadways—one at a high, and one at a low, level across the middle span.” “And is the low level to be a drawbridge—a roadway that can be drawn up to permit vessels to pass? Is that so?” “Exactly. And this drawbridge will be in two parts, one on either side; they will be worked from two massive piers giving a clear span of 200 feet in the middle of the stream, through which span big vessels can pass. The usual traffic of the river will be able to pass even when the drawbridges are down.” “And above the bascules or drawbridges will run the high-level bridge?” “Yes, a girder bridge for footpaths, and people will reach it by lifts and staircases in the piers—which, by-the-by, will be more like huge towers. These towers will also contain the machinery for raising and lowering the drawbridges.” “And what sort of bridge will be used for the other spans—that is, to cross the river between the piers and the shore?” “Suspension bridges; so that the Tower Bridge as it will be called, for it will cross the Thames by the Tower of London, will embody the suspension, the bascule (or drawbridge), and the girder bridge principles, while in the centre will be two levels.” “It promises to be a splendid piece of work.” “It does. And it is very much needed, for the congestion of traffic on London Bridge is terrible.” “And people have often to come round a long way to reach it.” The promise of the Tower Bridge, as set forth by these speakers, has been amply fulfilled. It is indeed a fine piece of work; and although it does not embody any new idea, yet in its combination and development of old principles and in its size it is very remarkable. It was opened in June, 1894, and is, or was at the time of building, the biggest bascule bridge in the world.