The particular spot in the Campus Martius to which we will direct our steps, is one whose situation is so definite, that we can accurately describe it to any one acquainted with the topography of ancient or modern Rome. In republican times there was a large square space in the Campus Martius, surrounded by boarding, and divided into pens, in which the _Comitia_, or meetings of the tribes of the people, were held, for giving their votes. This was called the _Septa_, or _Ovile_, from its resemblance to a sheepfold. Augustus carried out a plan, described by Cicero in a letter to Atticus,[2] of transforming this homely contrivance into a magnificent and solid structure. The _Septa Julia_, as it was thenceforth called, was a splendid portico of 1000 by 500 feet, supported by columns, and adorned with paintings. Its ruins are clearly traceable; and it occupied the space now covered by the Doria and Verospi palaces (running thus along the present Corso), the Roman College, the Church of St. Ignatius, and the Oratory of the Caravita. The house to which we invite our reader is exactly opposite, and on the east side of this edifice, including in its area the present church of St. Marcellus, whence it extended back towards the foot of the Quirinal hill. It is thus found to cover, as noble Roman houses did, a considerable extent of ground. From the outside it presents but a blank and dead appearance. The walls are plain, without architectural ornament, not high, and scarcely broken by windows. In the middle of one side of this quadrangle is a door, _in antis_, that is, merely relieved by a tympanum or triangular cornice, resting on two half columns. Using our privilege as “artists of fiction,” of invisible ubiquity, we will enter in with our friend, or “shadow,” as he would have been anciently called. Passing through the porch, on the pavement of which we read with pleasure, in mosaic, the greeting SALVE, or WELCOME, we find ourselves in the _atrium_, or first court of the house, surrounded by a portico or colonnade.[3] [Illustration: Door of Pansa’s house, with the greeting SALVE or WELCOME.]