This ancient gate has a pointed arch; it belongs to the so-called “Cyclopean style.” Sir William Smith gives an illustration of the Porta dell’ Arco, and refers to “the very singular construction,” in which successive courses of stone “project over each other till they meet, so as to form a kind of pointed arch.” Yet the construction is in no respect very singular, being the simplest way in which rude arches can be copied from Nature’s models. With toy bricks of wood a child can build a Porta dell’ Arco.[60] On the other hand, art and science go together in the building of an arch with voussoirs and keystones. A long evolution separates this workmanship from the gateways at Arpino and Tiryns and Mycenae, though we cannot follow it through its gradual improvements. It is an evolution with many breaks, many related forms having perished; but experts note a difference between the Porta dell’ Arco at Arpino and similar vaults both at Mycenae and at Tiryns, where the craftsmanship dates from the Heroic Age in Greece. The main entrance at Mycenae is called the Lion Gate, from the famed triangular arch and relief above its huge lintel-stone. The arch belongs to the method of laying stones in horizontal courses that jut out towards each other across an opening; and the decorative sculpture represents two lions that stand face to face; they are separated by a pillar and their front legs rest on a low altar-like structure that supports the pillar. The same device occurs in cut gems and in goldsmith’s work of the Mycenaean age; and the lions recall to memory those with which some Chinese bridges have been ennobled (pp. 127, 311). Even more remarkable are the beehive tombs at Mycenae; there are eight in all, and some others are found in the neighbourhood. Pausanias regarded them as the places where Atreus and his sons hid their treasures, but now they are looked upon as the tombs of princely families. The most important of them, just outside the Lion Gate, is called the Treasury of Atreus. It has two rooms, a square one cut in the rock, and a round one with a pointed dome. This chamber is fifty feet in height and in diameter; we go to it along a horizontal passage twenty feet wide and a hundred and fifteen feet long, with side walls of squared stone sloping up to a height of forty-five feet. “The doorway was flanked with columns of alabaster, with rich spiral ornament, now in the British Museum; and the rest of the façade was very richly decorated, as may be seen from Chipiez’s fine restoration. The inside of the vault was ornamented with attached bronze ornaments, but not, as is sometimes stated, entirely lined with bronze. It is generally supposed that these tombs, as well as those excavated in the rock, belong to a later date than the shaft tombs on the Acropolis.”[61]