The Tower Bridge, as compared with other great engineering works of the kind, labours under the disadvantage of not being seen properly from anywhere as a whole, taking in, that is, both abutment towers with their pendant suspension chains, which add so much to the general effect. Nevertheless, even viewed from close by, it is very telling, and dwarfs immeasurably any other building near it; see, for instance, how the little Tower of London, that ancient and most historic fortress, loses its size from its close juxtaposition to those supporting towers! The "bascules," or drawbridges, are worked by hydraulic power, and it is a curious and interesting sight to see them raised to allow tall vessels to pass. Below the Tower Bridge, the broad river seems to extend in a sea of masts, the city to become a world of wharves and docks. To quote, once more, an "impression" of M. Gabriel Mourey: "Once past the London Tower Bridge, and its two enormous towers, which rise like a triumphal arch with an air of calm victory at the entrance to the great metropolis, the seaport aspect of London becomes very apparent. The immense traffic on the river is evident from the constant passage of steamers, no less than by their frequent calls at the wharves whose blackened walls, deep in water, receive the riches of the entire world. A whole people toil at the unloading of the enormous ships; swarming on the barges, dark figures, dimly outlined, moving rhythmically, fill in and give life to the picture. In the far distance, behind the interminable lines of sheds and warehouses, masts bound the horizon, masts like a bare forest in winter, finely branched, exaggerated, aerial trees grown in all the climates of the globe. Steam-tugs whistle, pant, and hurry; ships with great red sails descend the river towards the sea. An enormous steamer advances majestically; she seems as tall as a five-storied house and her masts are lost in the mist. The river suddenly widens, the thick smoke of the atmosphere almost prevents one from seeing the other side; it might almost be an immense lake. Rain, steam, and speed;--Turner's chef d'oeuvre evoked before my eyes. The ever-changing sky is a continual wonder. A while ago the sun, like a disc of melting cream, disappeared in yellowish mists, scattering reflections like dirty snow. Now, through a clearing, he appears like the altar-glory of a Jesuit church; raining waves of golden light; the surrounding cloud-flocks are in a moment tinged with brilliance. And again, he is suddenly eclipsed; all returns to dulness and gloom: it might be the sad dawn of a rainy day."