About 200 yards farther on we pass under the Arch of Titus. The bas–relief, exhibiting the triumphal procession and captive Jews, is of itself sufficient to confer a lasting interest upon this arch. It forms a grand contemporaneous record of the siege of Jerusalem, and of the forms of some of the sacred furnishings of the temple. Here we find and drive over a portion of the veritable paving–stones of an old Roman road, the Via Sacra. Considering how frequently our roads and streets require to be re–paved, re–laid, or re–macadamized, it seems little short of a miracle that any portion of the old Roman paving should have remained for so many centuries. But the Roman roads were constructed in a special manner, with the great object in view of ensuring their being solid, dry, level, and direct. The under foundation was of three courses of broken stones of different given sizes for each course, and altogether 3 feet deep, with a top course of closely–jointed stone, generally basalt, a foot thick. The roads were narrow, sometimes only 12 feet wide, and had a rise of 3 inches in the centre to allow the rain to run off. The making of roads was considered a matter of prime importance and a most laudable undertaking, so that enormous sums were spent on them. In Britain alone there were 2500 miles of Roman roads. The roads of Rome were the more durable, inasmuch as they were not subjected to the heavy traffic of our streets, the carriages being small and light; while, as no gas and water pipes underlay them, there was no everlasting turning of them up to get at things below, and as little were there tramway lines to shake the foundations or injure the surface.