The office of Pontifex Maximus, or chief priest, was to declare and interpret the divine law, or, rather, to preside over sacred rites; he not only prescribed rules for public ceremony, but regulated the sacrifices of private persons, not suffering them to vary from established custom, and giving information to every one of what was requisite for purposes of worship or supplication. He was also guardian of the vestal virgins, the institution of whom, and of their perpetual fire, was attributed to Numa, who, perhaps, fancied the charge of pure and uncorrupted flames would be fitly intrusted to chaste and unpolluted persons, or that fire, which consumes, but produces nothing, bears an analogy to the virgin estate. In Greece, wherever a perpetual holy fire is kept, as at Delphi and Athens the charge of it is committed, not to virgins, but widows past the time of marriage. And in case by any accident it should happen that this fire became extinct, as the holy lamp was at Athens under the tyranny of Aristion, and at Delphi, when that temple was burnt by the Medes, as also in the time of the Mithridatic and Roman civil war, when not only the fire was extinguished, but the altar demolished, then, afterwards, in kindling this fire again, it was esteemed an impiety to light it from common sparks or flame, or from anything but the pure and unpolluted rays of the sun, which they usually effect by concave mirrors, of a figure formed by the revolution of an isosceles rectangular ********, all the lines from the circumference of which meeting in a centre, by holding it in the light of the sun they can collect and concentrate all its rays at this one point of convergence; where the air will now become rarefied, and any light, dry, combustible matter will kindle as soon as applied, under the effect of the rays, which here acquired the substance and active force of fire. Some are of opinion that these vestals had no other business than the preservation of this fire; but others conceive that they were keepers of other divine secrets concealed from all but themselves, of which we have told all that may lawfully be asked or told, in the life of Camillus. Gegania and Verenia, it is recorded, were the names of the first two virgins consecrated and ordained by Numa; Canuleia and Tarpeia succeeded: Servius afterwards added two, and the number of four has continued the present time.
The statutes prescribed by Numa for the vestals were these: that they should take a vow of virginity for the space of thirty years, the first ten of which they were to spend in learning their duties, the second ten in performing them, and the remaining ten in teaching and instructing others. Thus the whole term being completed, it was lawful for them to marry, and, leaving the sacred order, to choose any condition of life that pleased them; but this permission few, as they say, made use of; and in cases where they did so, it was observed that their change was not a happy one, but accompanied ever after with regret and melancholy; so that the greater number, from religious fears and scruples, forbore, and continued to old age and death in the strict observance of a single life.
For this condition he compensated by great privileges and prerogatives; as that they had power to make a will in the lifetime of their father; that they had a free administration of their own affairs without guardian or tutor, which was the privilege of women who were the mothers of three children; when they go abroad, they have the fasces carried before them; and if in their walks they chance to meet a criminal on his way to execution, it saves his life, upon oath made that the meeting was an accidental one, and not concerted or of set purpose. Any one who presses upon the chair on which they are carried, is put to death. If these vestals commit any minor fault, they are punishable by the high priest only, who scourges the offender, sometimes with her clothes off, in a dark place, with a curtain drawn between; but she that has broken her vow is buried alive near the gate called Collina, where a little mound of earth stands inside the city, reaching some little distance, called in Latin agger;under it a narrow room is constructed, to which a descent is made by stairs; here they prepare a bed, and light a lamp, and leave a small quantity of victuals, such as bread, water, a pail of milk, and some oil; that so that body which had been consecrated and devoted to the most sacred service of religion might not be said to perish by such a death as famine. The culprit herself is put in a litter, which they cover over, and tie her down with cords on it, so that nothing she utters may be heard. They then take her to the forum; all people silently go out of the way as she passes, and such as follow accompany the bier with solemn and speechless sorrow; and indeed, there is not any spectacle more appalling, nor any day observed by the city with greater appearance of gloom and sadness. When they come to the place of execution, the officers loose the cords, and then the high priest, lifting his hands to heaven, pronounces certain prayers to himself before the act; then he brings out the prisoner, being still covered, and placing her upon the steps that lead down to the cell, turns away his face with the rest of the priests; the stairs are drawn up after she has gone down, and a quantity of earth is heaped up over the entrance to the cell, so as to prevent it from being distinguished from the rest of the mound. This is the punishment of those who break their vow of virginity.