were striving after something beyond the mere horizontal lintel resting on two vertical supports. The builders of Segni had not got so far as those of Veii or Tusculum; as they had no idea of the true principle of the arch, so they had no idea of its form; all they could do was to place two horizontal stones with sides sloping inwards immediately under the lintel. In truth, the construction is still purely that of the lintel, and nothing else; but the form chosen shows a certain vain striving after something different. As such, it is no small lesson which it teaches; and the effect of the great stones thus piled together to form the entrance is striking and solemn. It carries us back from days which on our side of the Alps we deem ancient, but when the arts of construction were as well known as they are now, to days when men were making the first rude attempts towards the greatest of constructive inventions. Attempts of this kind, simply because they are mere attempts, failures and not successes, have a more ancient look than those examples where the builders were fully satisfied with the lintel construction and attempted no other. In point of fact, whatever their relative date, they are later in idea, as showing a desire to innovate on the received form, some instances of which were at last crowned with success. It is not easy to see how this gate came by its local name. One can understand the process of thought by which the roofing at Tusculum, which has the outward shape of the pointed arch, came to be called _arco Gotico_; it is harder to guess why the great primæval gate of Segni should be attributed to Saracens. It is far from being the only primæval gateway in the whole circuit. No less than five have been counted between the outer and inner walls, and two more in the part of the enclosure occupied by the modern town, where the two lines of wall coincide. Hard by _Porta Saracenesca_ itself is a small sally-port; of the others, the larger ones, like _Porta Saracenesca_ itself, stand at right angles to the wall. Some of them at least show the same strivings after the arch as their greater neighbour. The nature of the ground forbids the _arx_ from reaching any great height above the rest of the city; but its place is easily marked. It contains a singular large cistern of Roman work, and close by is one of those junctions of different ages which always preach to us a living historic lesson. Here is the terrace of a temple wrought with stones of the primitive construction. On this primitive work rise the remains of the _cella_ in Roman masonry, and the Roman wall of the _cella_ is now carried up to form a church. Now, at least the church is of no architectural value, but it is none the less a witness to the greatest of all the changes which the hoary walls of Signia have looked upon.