The city is built upon a group of islands; its houses are founded on piles, for there is no really solid ground. How far the present canals correspond with the original channels between small islands, how far they are artificial, it is difficult to say; but whether the original islets were few or many, there can be no doubt that they were formerly divided by the largest, or the Grand Canal, the _Rio Alto_ or Deep Stream. This takes an S-like course, and parts the city roughly into two halves. The side canals, which are very numerous, for the town is said to occupy one hundred and fourteen islands, are seldom wider, often rather narrower than a by-street in the City of London. In Venice, as has often been remarked, not a cart or a carriage, not even a coster's donkey-cart, can be used. Streets enough there are, but they are narrow and twisting, very like the courts in the heart of London. The carriage, the cab, and the omnibus are replaced by the gondolas. These it is needless to describe, for who does not know them? One consequence of this substitution of canals for streets is that the youthful Venetian takes to the water like a young duck to a pond, and does not stand much on ceremony, in the matter of taking off his clothes. Turn into a side canal on a summer's day, and one may see the younger members of a family all bathing from their own doorstep, the smallest one, perhaps, to prevent accidents, being tied by a cord to a convenient ring; nay, sometimes as we are wandering through one of the narrow _calle_ (alleys) we hear a soft patter of feet, something damp brushes past, and a little Venetian lad, lithe and black-eyed, bare-legged, bare-backed, and all but bare-breeched, shoots past as he makes a short cut to his clothes across a block of buildings, round which he cannot yet manage to swim.