breeze to cool the air. Europeans there die fo faft that they have not time to degenerate. Even in Jamaica, though more temperate by a regular fucceffion of land and feabreezes, recruits from Britain are necessary to keep up the numbers. The climate of the northern provinces resembles our own, and population goes on with great rapidity. Thus it appears that there are different races of men fitted by nature for different climates. Upon a thorough examination another fact will, perhaps, alfo appear, that the natural productions of each climate make the most wholesome food for the people who are fitted to live in it. Between the tropics, the natives live chiefly on fruits, feeds, and roots; and, it is the opinion of the moft knowing naturalifts, that fuch food is of all the most wholesome for the torrid zone, comprehending the hot plants, which grow there to perfection, and tend greatly to fortify the ftomach. In a temperate climate, a mixture of animal and vegetable food isheld to be the moftwholesome; and there both animals and vegetables abound. In a cold climate, animals are in plenty, but fcarce any vegetables that can ferve for food to man. What phyficians pronounce upon that head, I know not; but if we dare venture a conjecture from analogy, animal food will be found the moft wholefome for fuch as are made by nature to live in a cold climate. M. Buffon, from the rule, That all animals which can procreate to gether, and whofe progeny can alfo procreate, are of one fpecies, concludes, that all men are of one race or fpecies; and endeavours to fupport that favourite opinion by afcribing to the climate, to food, or to other accidental caufes, all the varieties that are found among men. But is he feriously of opinion, that any operation of climate, or of other accidental caufe, can account for the copper colour and smooth chin univerfal among the Americans, the prominence of the pudenda univerfal among Hottentot women, or the black nipple no less univerfal among female Samoides ? The thick fogs of the island of St. Thomas may relax the fibres of the natives, but cannot make them more rigid than they are naturally. Whence then the difference with refpect to the rigidity of fibres between them and Europeans, but from original nature? It is in vain to afcribe to the climate the low ftature of the Efquimaux, the smallnefs of their feet, or the overgrown fize of their head. It is equally in vain to afcribe to climate the low ftature of the Laplanders, or their ugly vifage. Lapland is, indeed, piercingly cold; but fo is Finland, and the northern parts of Norway, the inhabitants of which are tall, comely, and well proportioned. The black colour of negroes, thick lips, flat nofe, crifped woolly hair, and rank fmell, diftinguish them from every other race of men. The Abyffinians, on the contrary, are tall and well made, their complexion a brown olive, features well propor By late accounts it appears that the Laplanders are only degenerated Tartars; and that they, and the Hungarians, originally fprung from the fame breed of men, and from the fame country. Pere Hel, the Jefuit, an Hungarian, made lately this difcovery, when fent to Lapland for making some aftronomical obfervations. tioned, eyes large, and of a fparkling black, thin lips, a nofe rather high than flat, There is no fuch difference of climate between Abyffinia and Negroland as to produce thefe ftriking differences. At any rate, there must be a confiderable mixture both of foil and climate in these extenfive regions; and yet not the leaft mixture is perceived in the people. USE. USEFUL PROJECTS. Some Extras, from a pra&ical Elay on a Cement, and Artificial Stone, justly fuppofed to be that of the Greeks and Romans, lately redifcovered by Monf. Loriot, Maf ter of Mechanics to his moft Chrif tian Majefty; for the cheap, eafy, expeditious, and durable Conftruction of all Manner of Buildings, and Formation of all Kinds of Or. naments of Architecture, even with the commoneft and coarfest Materials. Tranflated from the French Original, lately published, by the exprefs Orders of that Monarch. Otwithstanding the great de art formed by the ftudy of those monuments left us by the ancients, has fucceeded fo far as to produce edifices capable of vying with their patterns, it may be fairly faid, that we are at a great remove from the Greeks and Romans, with respect to the running up of buildings with the degree of rapidity they used to do; and yet beftowing on them that degree of folidity, which feems to defy time itself; and all this, with almost every kind of materials they could lay their hands upon. It is, no doubt, an easy matter to raise lasting edifices by piling one upon enormous blocks Ngree of perfection which offtone. But then, there are lis the arts have attained within a few centuries, it cannot be denied, that in looking over the writings of the ancients, and examining their monuments, we meet with certain figns of their having been acquainted with some secrets, to which we, moderns, are utter ftrangers. We are, no doubt, very rich without them; but that is no reason why we should not endeavour to recover them; and, instead of trufting to chance, employ both obfervation and experiment for that purpose. Of this, one of the most important branches of architecture is a ftriking proof. Though the ge. nius of our modern masters in that Be veral countries, of very confiderable extent, in which no fuch ma terials are to be had; and there are others, in which, though these materials abound, they are of too loofe a texture to refift, for many years, the viciffitudes of the weather. fides, this way of going to work is monstrously expenfive. It is what very few fimple fubjects can pretend to; and, accordingly, few of the houses built by them are of any duration. Nay, ftates themselves are now often obliged to renounce the execution of the most useful works, on account of the enormous expence attending them in the modern mhod. But But the Romans, it is plain, generally employed, efpecially in thofe public works in which usefulness was more to be attended to than ornament, a far lefs expenfive mode of construction. The principal part of fuch works, if not the whole of them, ufually confifted of materials of a very fmall bulk, but kept together by a mortar or cement of a moft binding quality. What a fine method! One can hardly fum up all the advantages attending it. In it, they could make use of every kind of fluff already exifling on the furface of the earth, and even ftones, every where almoft to be met with in the beds of rivers and torrents, though worn round, nay, and polifhed, by their conftant attrition against each other, or other bodies. They had no occafion for the unweildy apparatus of heavy carriages to bring their materials to the spot, or cumbrous engines to raise them; confequently, they loft neither time nor labour in the execution of thofe tedious operations; all went directly to the forwarding of the work itfelf, which, of course, muft have fhot up with uncommon rapidity. How, otherwife, could they have executed, even with their numerous armies, thofe immenfe piles; thofe aqueducts of feveral leagues in length, and fometimes rifing to the level of mountains; and all this often, merely to fupply fome middling town with water, not only for the neceffary, though common, purposes of life; but even for thofe of luxury and magnificence; fuch as baths, fountains, &c. Thefe confiderations did not ef cape Monfieur Loriot, fo defervedly celebrated for his many very ufeful mechanical difcoveries and inventions; and, it was in confequence of them he made these inquiries and refearches; the fruits of which I am now going to communicate to the public. Ever taken up withthe thoughts of ferving his country and mankind, by cultivating and improving the fine and the ufeful arts, the great number of those vat remains of Roman grandeur, fcat. tered over our fouthern provinces, could not fail of fuggefting to him, that the folidity, fo confpicuous in them, could not be owing to any fecret confined to any one portion of mankind, nor to any merely local advantages, nor to any peculiar excellency in the quality of the materials; but that it must be the refult of fome common and easy method, within the reach of every man in the world of workmen employed in these erections. But, perhaps, we had better follow the example of Monfieur Loriot: and, like him, particularly analyse these ftupendous monuments, and thence regularly deduce the manner in which, it may be prefumed, the Romans conftructed them. Moft of these monuments exhibit nothing but enormous maffes in point of thickness and height, the heart of which, but juft faced with an almoft fuperficial coating, evi * Of this we have an inftance in the ruins of an ancient Roman building on the banks of the Rhone at Lyons, a little above St. Clare's quay. It is eafy to fee, that even the pebbles, found in the bed of this river, make part of the work: but they are fo ftrongly bound together, that it is much easier to break them, than to make them let go their hold of the cement, which fills all the interRices between them. dently dently confifts of nothing but pebbles and other fmall ftones, thrown together at random, and bound by a kind of mortar, which appears to have been thin enough to penetrate the smallest interftices, and fo form a folid whole with these materials, which ever kind was first laid to receive the other when poured into it. It is enough, therefore, to confider thefe ruins, with the fmalleft degree of attention, to be convinced that all the fecret of this mode of construction confifted in the method of preparing and ufing this frange kind of mortar; a mortar not liable to any decay; bidding defiance equally to the perpetual erofions of time, and heaviest ftrokes of the hammer and pickaxe. At least, when any little ftone, and it must be a round one, gives way to them, the mould of cement left by it is found equally hard with the compleateft petrifi cation. How different, then, muft this ancient mortar be from the very best of our modern! The latter, one would imagine, never dries perfectly, but to fall to duft again at the leaft touch. Of this the remarkable crumbling away of our most recent buildings is an evident proof. Another of the extraordinary qualities of this Roman cement, is, its being impenetrable to water. This is not a mere conjecture. It is a fact, which the aqueducts of theirs, ftill in being, leave not the leaft room to doubt of; for, in these works, they never employed either clay, maftich, or any other refinous substance, to prevent the waters making their way through them. The areas of thefe canals, resting fometimes on the ground, fometimes on a wall, and fometimes on arches, built for the purpose, as well as their roof and fides, con fifted of the fame kind of finall ftones, bound together by this extraordinary cement; with this dif. ference, that the infide furface was compofed of finer and smaller ingredients, which, at the fame time that it does not look any thing like a coating made at fecond hand, and of courfe capable of being fcaled off, carries evident marks of its being the refult of a peculiar operation, which it may not be impoffible to imitate by carefully attending to the obfervations that will occur in the courfe of this Effay. Thus, then, it plainly appears, that these works were carried on by means of caffoons. The trenches made for the foundation formed, of themfelves, the loweft tire; and, furely, nothing could be eafier than to fill thefe with the materials ready prepared for that purpofe; tho' the Romans, no doubt, did it with their largest and heaviest tones. After bringing the work to the furface, they had recourfe to planks made to fit into each other, fucceffively extending them in length and in height, and binding the oppofite ones at fuch a diftance from each other, as to form the thickness of the wall; and, withal, with fufficient ftrength not to deviate ever fo little, from the perpendicular, on either fide. It was thus that they formed, as it were in a mould, thefe enormously maffy walls, compofed, as we have already feen, of every fpecies of pebbles, and other fmall ftones, which our modern architects know not what to do with for want of a mortar qualified to conftitute with them one folid compact body. We |