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TRY A MINERALIZED PAVEMENT.

The suggestion of our worthy Mayor, that Broadway be repaired with granite upon a bed of concrete, has elicited much comment from the press, and the whole interminable topic of street-pavement seems fairly to be revived.

With all deference to the more matured opinions of our contemporaries, we wish to say a few words, or rather to insinuate a few queries on the subject ourselves; and we shall put our observations in the shape of addenda to the valuable hints published by us a few days ago, and for which we were indebted altogether to a well-informed friend who has had especial opportunities of coming to a just conclusion in respect to the matter at issue.

His plan, it will be remembered, had reference chiefly to the manner of arranging wooden blocks — to the proper inclination to be given to them, with the object of preventing the two evils of swagging, or floating in wet weather, and of decay. The suggestions were highly ingenious, and for the purposes contemplated the pavement of our friend seems decidedly superior to the overlapping and riveted roads, called stereotomic, which for some years past have been the subject of experiment at Paris.

In that city the wooden blocks have been found, with slight exception, to remain sufficiently firm at all seasons; but there, as here, the insuperable difficulty has been decay, a difficulty which, as far as we can understand, has been only very partially overcome, either by stereotomizing the blocks, or depositing them with their pores inclined from the perpendicular.

There can be no doubt in the world that a very durable and excellent pavement can be formed of rudely wrought eighteen-inch cubes of hard stone, with the upper surfaces roughened, and the whole laid with merely common precaution as an ordinary brick trottoir. Where this experiment has been tried, it has met with the fullest success. The objections are, first, its cost, which, if the proper stone be employed, is very great; and secondly, the street din, which it does not obviate to a sufficient extent. The former objection is scarcely one at all, where funds are at command, for in the end it is infinitely the cheapest pavement which can be contrived by man; all the expense is in beginning; repairs will very rarely be needed. But the second objection is one of a vital importance, which we regret to perceive that our authorities are in some danger of overlooking. The loss in time (to say nothing of temper) through the intolerable nuisance of street-noise, would astonish all thinking people, if tangibly and mathematically put. We need say nothing, of course, about the vast inconvenience, and often fatal injury, which it occasions to invalids.

It is admitted on all hands that, as long as they last, the wooden pavements have every advantage over all other pavements which have been contrived. They make little noise; they are easily kept clean; they save a vast deal in horse-power; they are pleasant to the hoof; and in the wear and tear of vehicles save at least twenty per cent. Much may be said, too, of the economy of time, through the increased rapidity of passage to and fro.

The first objection is that of injury to the public health, through the miasma from decaying wood; but as this point is involved in decay itself, we may dismiss it and speak of the latter alone.

There is nothing in all experimental philosophy which has been more unequivocally demonstrated than the fact that, by a very simple process, even the greenest wood may be preserved for centuries, from decay. To test this, blocks, properly prepared, were subjected, for three years, in the fungus pit of the dock-yard at Woolwich, to all the know decomposing agents which can ever naturally be brought to act against wood, and at the expiration of the period, these blocks were found as perfect in every particular as when originally deposited in the pit. A thousand similar experiments have had identical results. The fact is established.

The preservative principle is that of mercury, and it is most readily employed in the bi-chloride (corrosive sublimate.) Let a pound of sublimate be dissolved in sixteen gallons of water, and a piece of even the sappiest wood (not rotten) be immersed in the decoction for seventy-two hours, and the wood cannot afterwards be rotted. By injection in vacuo the mineralization can be effected instanter.

The cost of the bi-chloride of mercury is, we presume, at present, something less than a dollar per pound, at retail, and at present. Should demand arise, however, to any considerable extent, quicksilver mines now unworked would be forthwith put into operation, and we should soon get the article for thirty or forty cents. The cost of mineralizing our pavements, under such circumstances, would be trivial indeed. It would be trivial even now. Decay being arrested, the public ill-health resulting, or said to result, form such decay, is of course to be left out of the question; and lest some of our fanciful friends may imagine that ill consequences might arise from the mercurial effluvium, we take occasion to state that no perceptible effluvia arise, and that repeated experiments in the close holds of mineralized ships, have demonstrated that no apprehensions on this score are to be entertained.

Now the only question in the matter which seems to us unanswerable, is the simple one — “why has not the mineralizing process been adopted in the preparation of the wooden blocks with which we have so frequently experimented in the pavement of our streets?”

But perhaps it has; and perhaps we are only evincing our want of information in regard to the municipal affairs. If so, we shall rejoice to be set right — if not so, we shall be equally glad to hear the arguments which are advanced in objection to experimenting now.