Our present knowledge of Ostia, extending far beyond the early _castrum_ discussed in Chapter IV, is due in large part to the devoted skill of Guido Calza. Under some pressure from Mussolini, who wanted the dig finished for an exposition scheduled for 1942 (but never inaugurated), he supervised the removal in four years of over 600,000 cubic yards of earth, recovering some seventy of the 170 acres enclosed within Ostia’s Sullan wall. What he uncovered he rejuvenated but did not falsify: his method was much the same as Spinazzola’s in Pompeii. This was his principle: “Better to brace than repair, better repair than restore, better restore than embellish; never add or subtract.” His aim was not to suppress inconvenient ugliness, but to remove impediments to study and understanding. He restored mosaics, making a clear distinction between the old _tesserae_ and the new; re-erected columns, put balconies back in place, rebuilt wooden ceilings to protect houses from the weather. He detached wall-paintings, reinforced them with cement and wire mesh, and replaced them, covered with glass, and protected against mold by the insertion of lead plates into the wall below the painting, to retard the spread, by capillary action, of dampness. He sealed the tops of walls, freed flights of stairs from rubble, opened out windows which had been bricked up in late antiquity. He planted trees, and set a privet hedge to mark the line of the city wall. He restored the ancient drainage-system. The result of all this careful work was to present to the modern world a picture of Roman life under the Empire only a shade less vivid than Pompeii. And the picture is not of a provincial town, but of the very vestibule of Rome itself, in fact a Rome in miniature, for Ostia gives an excellent notion of what life in the metropolis was like at the height of the Empire. And thanks to the careful work on the brick stamps by Professor Herbert Bloch of Harvard, most of the buildings excavated can be dated with a very fair degree of precision, so that Ostia’s development can be accurately traced from end to end.