Vitruvius was a cultured engineer and architect. He was employed in the service of the Roman State at the time of Augustus, shortly before the beginning of the Christian era. He planned basilicas and aqueducts, and designed powerful war-engines capable of hurling rocks weighing three or four hundred pounds. He knew the arts and the sciences, held lofty ideals of professional conduct and dignity, and was a diligent student of Greek philosophy.

We know of him chiefly from his ten short books on Architecture (De Architectura, Libri Decem), in which he touches upon much of the learning of his time. Architecture for Vitruvius is a science arising out of many other sciences. Practice and theory are its parents. The merely practical man loses much by not knowing the background of his activities; the mere theorist fails by mistaking the shadow for the substance. Vitruvius in the theoretical and historical parts of his book draws largely on Greek writers; but in the parts bearing on practice he sets forth, with considerable shrewdness, the outcome of years of thoughtful professional experience. One cannot read his pages without feeling that he is more at home in the concrete than in the abstract and speculative, in describing a catapult than in explaining a scientific theory or a philosophy. He was not a Plato or an Archimedes, but an efficient officer of State, conscious of indebtedness to the great scientists and philosophers. With a just sense of his limitations he undertook to write, not as a literary man, but as an architect. His education had been mainly professional, but, the whole circle of learning being one harmonious system, he had been drawn to many branches of knowledge in so far as they were related to his calling.

In the judgment of Vitruvius an architect should be a good writer, able to give a lucid explanation of his plans, a skillful draftsman, versed in geometry and optics, expert at figures, acquainted with history, informed in the principles of physics and of ethics, knowing something of music (tones and acoustics), not ignorant of law, or of hygiene, or of the motions, laws, and relations to each other of the heavenly bodies. For, since architecture "is founded upon and adorned with so many different sciences, I am of opinion that those who have not, from their early youth, gradually climbed up to the summit, cannot without presumption, call themselves masters of it."

Vitruvius was far from sharing the view of Archimedes that art which was connected with the satisfaction of daily needs was necessarily ignoble and vulgar. On the contrary, his interest centered in the practical; and he was mainly concerned with scientific theory by reason of its application in the arts. Geometry helped him plan a staircase; a knowledge of tones was necessary in discharging catapults; law dealt with boundary-lines, sewage-disposal, and contracts; hygiene enabled the architect to show a Hippocratic wisdom in the choice of building-sites with due reference to airs and waters. Vitruvius had the Roman practical and regulative genius, not the abstract and speculative genius of Athens.

The second book begins with an account of different philosophical views concerning the origin of matter, and a discussion of the earliest dwellings of man. Its real theme, however, is building-material—brick, sand, lime, stone, concrete, marble, stucco, timber, pozzolano. In reference to the last (volcanic ash combined with lime and rubble to form a cement) Vitruvius writes in a way that indicates a discriminating knowledge of geological formations. Likewise his discussion of the influence of the Apennines on the rainfall, and, consequently, on the timber of the firs on the east and west of the range, shows a grasp of meteorological principles. His real power to generalize is shown in connection with his specialty, in his treatment of the sources of building-material, rather than in his consideration of the origin of matter.

Similarly the fifth book begins with a discussion of the theories of Pythagoras, but its real topic is public buildings—fora, basilicas, theaters, baths, palæstras, harbors, and quays. In the theaters bronze vases of various sizes, arranged according to Pythagorean musical principles, were to be used in the auditorium to reinforce the voice of the actor. (This recommendation was misunderstood centuries later, when Vitruvius was considered of great authority, and led to the futile practice of placing earthenware jars beneath the floors of church choirs.) According to our author, "The voice arises from flowing breath, sensible to the hearing through its percussion on the air." It is compared to the wavelets produced by a stone dropped in water, only that in the case of sound the waves are not confined to one plane. This generalization concerning the nature of sound was probably not original, however; it may have been suggested to Vitruvius by one of the Aristotelian writings.

The seventh book treats of interior decoration—mosaic floors, gypsum mouldings, wall painting, white lead, red lead, verdigris, mercury (which may be used to recover gold from worn-out pieces of embroidery), encaustic painting with hot wax, colors (black, blue, genuine and imitation murex purple). The eighth book deals with water and with hydraulic engineering, hot springs, mineral waters, leveling instruments, construction of aqueducts, lead and clay piping. Vitruvius was not ignorant of the fact that water seeks its own level, and he even argued that air must have weight in order to account for the rise of water in pumps. In his time it was more economical to convey the hard water by aqueducts than by such pipes as could then be constructed. The ninth book undertakes to rehearse the elements of geometry and astronomy—the signs of the zodiac, the sun, moon, planets, the phases of the moon, the mathematical divisions of the gnomon, the use of the sundial, etc. One feels in reading Vitruvius that his purpose was to turn to practical account what he had gained from the study of the sciences; and, at the same time, one is convinced that his applications tend to react on theoretical knowledge, and lead to new insights through the suggestion of new problems.

The tenth book of the so-called De Architectura is concerned with machinery—windmills, windlasses, axles, pulleys, cranes, pumps, fire-engines, revolving spiral tubes for raising water, wheels for irrigation worked by water-power, wheels to register distance traveled by land or water, scaling-ladders, battering-rams, tortoises, catapults, scorpions, and ballistæ. On the subject of war-engines Vitruvius speaks with special authority, as he had served, probably as military engineer, under Julius Cæsar in 46 B.C., and had been appointed superintendent of ballistæ and other military engines in the time of Augustus. It was to the divine Emperor that his book was dedicated as a protest against the administration of Roman public works. In its pages we see reflected the life of a nation employed in conquering and ruling the world, with a genius more distinguished for practical achievement than for theory and speculation. Its author is truly representative of Roman culture, for nearly everything that Rome had of a scientific and intellectual sort it drew from Greece, and it selected that part of Greek wisdom that ministered to the daily needs of the times. In his work on architecture, Vitruvius shows himself a diligent and devoted student of the sciences in order that he may turn them to account in his own department of technology.

If you glance at the study of mathematics, astronomy, and medicine among the Romans prior to the time of Greek influence, you find that next to nothing had been accomplished. Their method of field measurement was far less developed than the ancient Egyptian geometry, and even for it (as well as for their system of numerals) they were indebted to the Etruscans. The history of astronomy has nothing to record of scientific accomplishment on the part of the Romans. They reckoned time by months, and in the earlier period kept a rude tally of the years by driving nails into a statue of Janus, the ancient sun-god. As we shall see, they were unable to regulate the calendar. Again, so far were they from contributing to the development of medicine that they had no physicians for the six hundred years preceding the coming of Greek science. A medical slave acted as overseer of the family health, and disease was combated in primitive fashion by prayers and offerings to various gods, who were supposed to furnish general health or to influence the functions of the different parts of the body. So rude was the native culture of the Romans that it is doubtful whether they had any schools before the advent of Greek learning. The girls were trained by their mothers, the boys either by their fathers or by some master to whom they were apprenticed.

The Greeks were conquered by the Romans in 146 B.C., but before that time Roman life and institutions had been touched by Hellenic culture. Cato the Censor (who died in 149 B.C.) and other conservatives tried in vain to resist the invasion of Greek science, philosophy, and refinement. After the conquest of Greece the master became pupil, and the conqueror was taken captive. The Romans, however, never rose to preëminence in science or the fine arts. A further development in technology corresponded more closely to their national needs, and in this field they came undoubtedly to surpass the Greeks. Bridges, ships, military roads, war-engines, aqueducts, public buildings, organization of the State and the army, the formulation of legal procedure, the enactment and codification of laws, were necessary to secure and maintain the Empire. The use in building construction of a knowledge of the right-angled triangle as well as other matters known to the Egyptians and Babylonians, and Archimedes' method of determining specific gravity were of peculiar interest to the practical Romans.