Greco-Roman antiquity never dreamed that it might be a useful, beautiful, glorious work to invent machines of increasing speed and power, and therefore never gave a thought to those technical elaborations which are the pride of our times. It possessed the elementary machines, the lever, jack-screw, the inclined plane; but it never tried to combine these into more complicated machines. In particular, it never called into play the effort to which all the mechanism of modern times owes its birth; that is to say, it never tried to endow its machines with a more rapid motion than the muscles of men or of animals can endow them with, or to search nature for motive forces of greater power than these. It availed itself only sparingly and on rare occasions of the force of running water or of the wind. The latter it used only for navigation, and even then with regret, hesitation, and fear, as if it were doing an illicit and shameful thing. It knew of no combustible other than the wood of the trees. Notwithstanding the fact that Pliny the elder has preserved for us so much precious information about agriculture and the ancient arts and industries, his writings contain scarcely a single hint suggesting that the men of his civilisation had any desire to make the instruments of economic production more perfect and effective. In one place, the sail, as compared with the oar, inspires him to write a passage in which the modern reader imagines just at first that he has lighted on a sentiment containing a distant echo of contemporary enthusiasm for progress. “Is there a greater marvel in the whole world?” he writes. A grass exists [flax, of which sails are made] which brings Egypt and Italy so close together that two prefects of Egypt, Galerius and Balbillus, crossed from Alexandria to the straits of Messina, one in seven days and the other in six; and that last summer the senator Valerius Marianus reached Alexandria from Pozzuoli in a light wind in nine days. There is a grass which brings me in seven days from Gades, the harbour near the Pillars of Hercules, to Ostia, in four from this side of Spain, in three from the province of Narbonne, in two from Africa, as C. Flavius, the envoy of the proconsul Vilius Crispus, found. Does it not seem as if we were reading an anticipation by eighteen hundred years of that hymn which moderns so often raise to the power of steam and to the great ocean liners which cross the Atlantic in five or six days? But ours is only a brief illusion. The wonder and the admiration of Pliny are soon over, and a sort of awe takes their place. “_Audax vita, scelerum plena!_” he quickly adds. “Creature full of wicked daring!” The invention of sails seems to him almost a sacrilegious impiety, and his view was that of all the ancients.