Fosso indicates, both by its straight-sided façade and by the square courtyard with the antique arrangement of the columns, the innovations of the new style; while the broad, projecting, wooden roof and the plain windows recall an earlier time. On the Trinity bridge the houses of the Capponi and Gianfigliazzi retain something of the ancient style. In the seventeenth century the interior of the house of the Albizzi, the residence of Piero, Maso, Rinaldo, was rebuilt. This building is in the street named after them, in which palace follows palace, though the full effect is lost, owing to the narrow space. The exterior bears, however, decidedly the mark of time, which is still more the case with the neighbouring palace of the Alessandri. The streets were mostly paved with flagstones (_lastrico_), even in the suburbs—a custom which gradually replaced the causeways of tiles (_ammattonato_) or of small stones (_selciato_); and when adopted in the smaller Tuscan towns contributed to give them a clean and well-to-do appearance. Even before the end of the thirteenth century this kind of pavement is said to have been used. The stones were procured from the hill of San Giorgio, adjoining the city on the left bank of the river, and the immediate neighbourhood, as well as from the quarries of Fiesole and Golfolina, already mentioned. For a long time the stones were left in their polygonal quarry form, until in recent times it was preferred to hew them square. The laborious and costly work required by a strong and perfectly uniform embankment to the sewers of the city would progress but slowly. It was placed under the careful superintendence of the commissariat officials (_officiales grasciæ_), to whom was especially entrusted the charge of those streets in which the Barbary-horse races took place.[36] The paving of the Place of the Annunziata—the centre of which remains, however, at the present day unpaved, like those of Sta. Maria Novella, San Marco, and others—was first undertaken, in 1421, by the Servite monks, who solicited subsidies for the purpose, in consideration of the crowds which thronged to the miraculous image in their church.