There are other drawbacks to servile labor: though a slave worker cannot “strike” against terms of employment, his employer cannot cease to feed and clothe him during slack times, when he will gladly lay off free labor. As a result the average industry employs slaves and free men side by side; the latter are a little more self-sufficient, but seemingly they do not object to having slaves as fellow workmen. In any case the hours of labor are long and the conditions hard. A denarius (16 cents) is apparently wages enough to provide an artisan with a few rooms in a dingy insula and to keep his wife and children from starvation--especially if they can get the government grain doles; greater reward he dares seldom to demand. =212. Great Trade through Ostia and the Campanian Ports.=--But Rome, as stated, imports more articles than she manufactures. The commerce from the interior of Italy, down the Tiber and along the main roads from the north, the Via Cassia and the Via Flaminia, is not of first importance--mostly garden produce, stone, and timber. Not so that from Ostia, the harbor town, or that coming by the famous southern highways, the Via Appia and the Via Latina. Navigation along the Italian coast to Ostia has its dangerous features, and a great many merchants try to unlade at such south-Latin ports as Antium or preferably at the busy harbor of Puteoli in Campania. The result is that the southern roads are often black with great trains of heavy wagons bumping over the hard pavement all the hundred and fifty odd miles from Puteoli to Rome. However, a very large fraction of the entire commerce of Rome passes up the Tiber from Ostia, and is set down on those long arrays of wharves southwest of the Aventine, known as the Emporium. =213. The Emporium and Its Wharves: the Tiber Barges.=--The Emporium is not the most beautiful section of Rome, but it is one of the most important. From its murk and bustle many a lordly eques is swung away every night in his litter for the quiet, aristocratic Quirinal or Esquiline; but it is the Emporium trade which makes possible his great mansion with its hierarchy of soft-footed slaves. To reach the Emporium we go down the Vicus Tuscus past the upper end of the tall gray masses of the far-stretching Circus Maximus, then turn down narrow lanes where the Aventine crowds closely toward the Tiber. Immediately the river opens before us with a scene of teeming life.