The Complete Works of Edgar Allan Poe - Edgar Allan Poe [801]
When this sort of pavement was first used, it was, like stone pavement, laid on gravel; but it was ultimately found that the water would get between the gravel and the wood, and the bed would turn to mud. Though the pavement did not break, it floated and waved under heavy weights. To remedy this defect, it was found necessary to form a basement of concrete, which was laid all over the street to the thickness of about 9 to 12 inches, and since this improvement has been introduced the success has been perfect. At the end of four years, in some of the greatest thoroughfares, not one half of the blocks of wood have been replaced, and the original cost in London is, we believe, 13d. Per square yard — thus joining economy to comfort.
The cost of keeping this pavement in repair is about 10 per cent, upon the capital.
STREET-PAVING
There is, perhaps, no point in the history of the useful arts more remarkable than the fact, that during the last two thousand years, the world has been able to make no essential improvements in road-making. It may well be questioned if the Gothamites of 3845 will distinguish any traces of our Third Avenue: — and in the matter of street-pavement, properly so called, although of late, universal attention has been directed to the subject, and experiment after experiment has been tried, exhausting the ingenuity of all modern engineers, it appears that we have at last settled on a result which differs in no material degree, and in principle not at all, from that which the Romans attained, as if instinctively, in the Via Appia, the Via Flaminia, the Via Valeria, the Via Tusculana, and others. There are streets in Pompeii to-day constructed on the very principle which is considered best by the moderns: or if there be any especial variation, it certainly is not to the credit of modern ingenuity.
The most durable and convenient of the Roman roads were thus composed: — The direction and breadth were first marked out by two shallow parallel furrows or trenches (sulci) from 15 to 8 feet apart, according to the importance of the via. The loose earth between the trenches was then taken away, and the soil farther removed until a sufficiently solid foundation was reached upon which to deposit the materials of the bed: — if from any cause, such as swampiness, no such natural basis was attainable, piles (fistucationes) were driven. Above the natural or artificial basis (the gremium) four strata were laid, of which the first (statumen) consisted of stones about three times the size of those employed by us in Macadamizing; next came the rudus, broken stones cemented with lime (answering to our rubble-work) — this was generally nine inches thick, and densely rammed. Then came the nucleus of broken earthen-ware, six inches thick, and also cemented with lime. Lastly came the true pavement, (pavimentum) which was composed of irregular polygons of silex, commonly basaltic lava. These blocks, however, were fitted together with great nicety, and presented just such an appearance as do our best built polygonal stone walls. The centre of the way was slightly elevated, as with us, above the curb-stones. Now and then, in cities, rectangular slabs of softer stone were substituted for the irregular lava polygons — and here the resemblance to the favorite modern mode was nearly complete. When the road or street passed over or through solid rock, the statumen and rudus were neglected, but the nucleus was never dispensed with. On each side of the way were elevated foot-paths, gravelled, and well supported; and at regular intervals were stone blocks, corresponding to our own steps, for the convenience of horsemen or carriages. Our mile-stones were also employed.
We are aware that all this is very school-boyish information