The duty of the augurs was to inquire into the divine will; and they could prevent any public business by declaring the omens unfavorable. The name is probably derived from an old Aryan word, meaning "sight" or "eye," which has come to us in the Greek αὐγή, and the German _auge_. Our words "auspicious" and "auspicate" are derived from the "auspices," or outlook on nature which these seers practised. For they were in truth the Roman _seers_. Their business was to look, at midnight, into the starry heavens; to observe thunder, lightning, meteors; the chirping or flying of birds; the habits of the sacred chickens; the appearance of quadrupeds; or casualties of various kinds, as sneezing, stumbling, spilling salt or wine. The last relics of these superstitions are to be found in the little books sold in Rome, in which the fortunate number in a lottery is indicated by such accidents and events of common life. The Romans, when at prayer, were in the habit of covering their heads, so that no sound of evil augury might be heard. The suppliant was to kiss his right hand, and then turn round in a circle and sit down. Many formulæ of prayers were prescribed to be used on all occasions of life. They must be repeated three times, at least, to insure success. Different animals were sacrificed to different gods,--white cattle with gilded horns to Jupiter, a bull to Apollo, a horse to Mars. Sometimes the number of victims was enormous. On Caligula's accession, one hundred and sixty thousand victims were killed in the Roman Empire. Lustrations were great acts of atonement or purification, and are often described by ancient writers. The city was lustrated by a grand procession of the four colleges of Augurs, Pontifices, Quindecemviri, and Septemviri. Lucan, in his Pharsalia, describes such a lustration.[291] Tacitus gives a like description, in his History,[292] of the ceremonies attending the rebuilding the Capitol. On an auspicious day, beneath a serene sky, the ground chosen for the foundation was surrounded with ribbons and flowers. Soldiers, selected for their auspicious names, brought into the enclosure branches from the trees sacred to the gods. The Vestal virgins, followed by a band of children, sprinkled the place with water drawn from three fountains and three rivers. The prætor and the pontiff next sacrificed a swine, a sheep, and a bull, and besought Jupiter, Juno, and Minerva to favor the undertaking. The magistrates, priests, senators, and knights then drew the corner-stone to its place, throwing in ingots of gold and silver.