But before pursuing the great story of what came afterwards, let us stand a while on the threshold of the tenth century and look at Venice as she was a few years after Saint Mark had taken her under his special protection.
In the first place, the alternate currents caused by the tide and the rivers were not yet completely controlled by stone-faced canals, and in many places the soil still consisted of long stretches of unstable mud, upon which the tide threw up masses of seaweed that lay rotting in the sun. The only means of obtaining a firm foundation for a stone building on such ground lay in laboriously driving piles, side by side, and so close that each one touched the next, and the whole formed a solid surface. It was a slow method, it was costly and required considerable skill; but the result was good, and has stood the test of a thousand years, for there are buildings standing to-day on piles driven in the year 900.
It follows that in the tenth century the majority of dwelling-houses were still only light constructions of wood, which could stand upon the mud without danger of sinking. There were many stone buildings already, however, but like their humbler neighbours they mostly had only one story above the ground floor, with small windows on the outside, and larger ones on the inner court, and all alike were roofed with thatch. It is hard to imagine Venice a thatched city, of all cities in the world; yet the reason of the peculiarity is plain enough. Neither brick nor tiles could be made from the soft mud of the lagoons, a wooden house cannot have a flat roof, and the construction of a vaulted roof upon a stone house requires a greater skill in building than the Venetians then possessed.
In building ordinary dwellings, Sagredo tells us that the usual method was to lay down a floor of heavy planks, upon which a thick layer of mortar and small pebbles was spread out and beaten down to a hard surface; upon this again a second layer of cement mixed with pounded bricks was spread, and this was beaten with heavy wooden beaters till it was perfectly hard and even. Precisely the same method is employed to-day in southern Italy; and it was from this beginning that the so-called ‘Venetian pavement’ soon developed. For rich people caused small pieces of coloured marbles, and even of mother-of-pearl, to be set into the cement of the second layer, which was then no longer beaten, but rolled with a ponderous stone roller and then rubbed down with a smooth stone and sand and water, and at last polished to a brilliant surface. To this day the ‘Venetian pavement’ is made in this way in all parts of the world. The Venetians had probably inherited the art directly from the Romans, together with some knowledge of mosaic, which it roughly resembles. The polished floor of the main room was an especial object of pride in the eyes of good housekeepers.