WHEELS. Mr. Cumming, in an essay on that subject, has compared and contrasted the properties of the cylinder and of the cone, and from them has demonstrated the effect which broad wheels, of the conical and of the cylindrical shape, must have on the roads, and on the labour of cattle; that wheels of a conical shape have a constant tendency to impair, and those of a cylindrical shape to improve them. By a most ingenious and well adapted apparatus, he has exhibited to us experiments proving, that there is a resistance from the partial dragging at the periphery of every wheel that is of a conical shape; that it grinds the hardest materials, and leaves the surface of the roads in a state to imbibe water, and adds considerably to the labour of the cattle; and that this resistance, so injurious to the roads, and to the cattle, is increased, by increasing the breadth of the conical wheel. That the cylindrical wheel, by its progressive dead pressure, consolidates and unites the materials, and leaves the surface smooth, close, and impenetrable to water; and that on a regular, well-formed, clean road, the resistance to the progress of the cylindrical wheel is not increased by increasing the breadth; and that the cylindrical shape is the best possible, it being, the only form of the rim that can have an equal velocity of all the parts of its periphery, And that from every circumstance, the cylindrical wheel is preferable to the conical, in every state of the roads; and in whatever state they may be, the cylindrical improves, and the conical impairs them. The SPOKES-are the radii of the wheel, and connect the nave with the rim or fellies. When the spokes stand square, or at right angles, to the axis, they derive no other advantage from that position than the actual strength of the timber of which they are made and are calculated only to bear a perpendicular pressure. When the spokes stand oblique, it gives the wheel a concave appearance on the side that is furthest from the carriage, which is called dishing; and the dishing gives to the wheel in some positions, much additional strength, from the affinity which it has to an arch. It is possible, that the dishing of the wheel was a consequence of the bending of the axis; and it being found that the dishing of wheels was attended with other advantages besides strength, they have been universally preferred, The narrower the rim of a wheel, the more damage it does the roads; and if cylindrical, the broader it is, consistently with other circumstances, the more it improves them. It seems deserving of consideration, whether the wheels of stage coaches, &c. ought not to be made broader than at present, considering the very great weights which they frequently carry. If the double weight of the high wheel in drawing up hill be compared with the diminution of the friction on the axis, it will be found on a general average to exceed out of all comparison. From which consideration, it would seem that wheels of a moderate height ought to be preferred, unless where particular circumstances may recommend the higher wheel. It appears, on the whole, that there remain sull so many doubtful points to be ascer tained, on the subject of wheels, that it would be desirable to institute a complete set of experiments, for the purpose of fixing the principles on which they ought to be constructed. These experiments should include each of the various particulars above alluded to, and ought to be tried, not in a cursory manner, but for a considerable period of time, in situations best calculated to produce results which can be depended on for their accuracy and universality. Preservation of the Roads. It must be obvious that, notwithstanding any improvements which may be made in the general construction or mode of conducting our carriages, or in the form and proportion of their different parts, and more especially of the wheels; however accurately all these may be contrived, according to true mechanical principles; yet if equal care and attention is not paid to the original formation, and, what is perhaps of equal importance, to the constant preservation of the roads, all the prudence of the economical carrier, all the ingenuity and skill of the mechanic, are of little avail. The man of curiosity who travels for his pleasure; the man of business who traverses the country in pursuit of his affairs; those whose occupation it is to supply one part of the kingdom with the produce of the other, or to convey from the interior to the sea ports the articles of our industry for foreign consumption; and those who are to be supplied by these means with the necessaries or luxu ries of life; are equally disappointed in their hopes, and where they look for pleasure, security, economy, and expedition, they have to encounter fatigue and danger, expence and delay. Next to the general influence of the seasons and of the weather (upon which we so much depend for the regular supply of our wants, and for a great portion of our comforts) there is perhaps no circumstance more interesting to men in a civilized state, than the perfection of the means of interior com munication; and it is deservedly our boast, that more attention has, upon the whole,' been already paid to this important object, in this country, than almost in any other part of the world. The best modes of forming roads are. now indeed pretty well understood, and carried The first relates to the improvements which might be made in the general laws regarding highways and turnpikes. Your Committee are decidedly of opinion, that these laws require to be re-considered; and perhaps it would be most advisable, though it would be an arduous task, to repeal the former laws, and to form the whole into one regular digest, which, from the experience of so many years since the laws were first enacted, may be considerably amended and improved. The idea of conveying goods and carriages on railways is likely to prevail, the more the subject is considered. In many cases railways are certainly preferable even to canals; and wherever they can be adopted, they are unquestionably better calculated than the common roads, for the conveyance of goods, more especially those of a heavy nature. An idea has occurred, of forming what may be called stone railways. The direction and the forming of roads are also points which merit the attention of Parliament. As to the first particular, it is well known that the roads in former times were not conducted in the manner the best calculated for the travelling of carriages heavily laden. Their course was frequently carried up steep ascents, to gain the open country and avoid the vallies, because the roads through the latter could not easily be made passable in the wet seasons of the year, without a labour and expence which it was perhaps then thought unnecessary to incur, when most even of the heavy articles of trade were carried on the backs of horses. Your Committee are of opinion, that, by examining the lines of the present roads, much improvement might be effected. Any such alterations must necessarily occasion expence, and may be liable to some objections; at the same time it is well worth the trial, and the first attempt might be made on the great line of road between London and Edinburgh, by which the capitals of the two kingdoms would be more closely connected; and if the advantages were found to be considerable, the same plan might afterwards be extended to other lines. The points they have alluded to in the report are of such infinite consequence to the convenience, the comfort, the commercial prosperity, and the personal security of their fellow subjects, that they will feel peculiar satisfaction, if any suggestions, which it has been in their power to collect, shall at all contribute to such important purposes. The present laws respecting the turnpikes are the 13 Geo. 3. ch. 84; 14 Geo. 3. ch. 14, 34, 57, 84; 16 Geo. 3. ch. 39, 44; 17 Geo. 3. ch. 10; 18 Geo. 3. ch. 28, 58; 21 Geo. The attention paid by our legislature to our public highways cannot but be pleasing to every one who considers the importance of those means of communication, and the immense and increasing traffic which is conducted upon them: we could, at the same time, be glad to direct the attention of the considerate to the state of the beasts of draught and burthen; to whose toil and activity we are infinitely beholden. Humanity unites with policy in recommending this enquiry, and we wish for the experimental remarks of practical men on the subject. By way. however, of shewing that we do not despise theory, we insert the following thoughts of an have ingenious foreigner, who seems to investigated this matter from very laudable motives. His principles are open to investigation as well as those of other writers: and we think that some of them are liable to exceptions: at least, until they have been further elucidated. ON THE PROGRESSIVE MOTION OF ANIMALS, AND THE MEANS OF CONVEYANCE. From Annales des Arts, No. 71. The Chevalier Fossombroni is member of the Institut at Bologna, of the academy at St. Petersburgh, &c. &c. From the days of Aristotle to the present time, authors who have written on the motion of quadrupeds, and especially on that of horses, have entertained different opinions, says M. de Fossombroni, respecting the disposition of their feet while in progress. Some think that the horse raises his feet alternately in a diago nal direction; others, that he lifts up the two on the same side. (1.) Some are of opinion that the disposition changes with corresponding changes in the mode of the animal's progression. The author of the present work shews, by a (1.) Artists and anatomists for a long time have been engaged in writing pro and con. Paolo Uccello, represented in the Metropolitan church of Florence, a warrior (I think Castruccio-Castracani) mounted on a horse, whose two feet are raised on the same side; while Jean Bologna constantly represented his horses with the feet of their different sides This last action is more pleasing to the eye, and the masses seem to be more collected, lifted up. very simple argument, analogous to the principles of plain geometry, that both motions may take place in the progress of quadrupeds. If we fix the four angular points of a rectangle, destined to advance one after the other, upon condition that one of the anterior points shall always precede one of the posterior ones, or vice versa, it is impossible that, in the prolonged execution of that movement, they should not so combine as to be alternately sometimes in a diagonal, and sometimes in a parallel direction. In like manner it happens, when a horse walks, if we observe the movement of the hind legs, that we may perceive that the fore leg on the same side moves next; and if the horse first steps out the fore foot, the hind foot, which is diagonal with respect to it, succeeds. Subsequent to this remark, M. de Fossombroni investigates the differences which may exist between the method of conveying goods upon horses' backs, or im carts. The useful researches which the author has published on one of the provinces of Etruria, called La Val di Chiana, have enabled him to collect a great number of facts in proof that the mules which carry burthens on their backs, are capable of service during ten or twelve years, especially in mountainous countries; (2.) while those mules that draw earts are unfit for labour after four years. In fact, in this latter occupation, animals have a greater number of muscles in action at one time, and their lungs become fatigued on account of their more frequently fetching breath. Observation teaches further, that the circulation of the blood is accelerated in proportion to the intensity of the efforts of the muscles, and that when the coats of the vessels are violently contracted, the rapidity of the circulating fluids is greatly increased. But the exigencies of commerce us (2.) It is important to pay attention to the height of the intended load, and to the particular distribution of the weight, before you load the animal; neither is the form of the packsaddle to be overlooked. To load the kneeling camel with facility, it is customary among the Arabs to raise the exterior branches of the pack-saddle to a great height, and, of course, the load. As the animal moves in his paces one may see the masses of lading alternately shaking backwards and forwards, which is of great injury to the animal, without any advantage in point of service. This inconvenience is not so remarkable in quadrupeds that are lower on their legs. It is advisable, therefore, to make the pack-saddle in such a manner that the load be as close as possible to the body of the animal, and that the common centre of gravity coincide with that of the quadruped on an horizontal plane. However, the pack-saddle or pannier must neither impede the breathing of the animal, nor the action of his museles. require the conveyance of a great quantity of goods and commodities in a given space of time, and the loss of the animals is not placed in competition with the advantages resulting from the speedier transit. An animal, when walking, incessantly vibrates from right to left like a pendulum, through the necessity of preserving the centre of gravity perpendicular with the base line. This centre of gravity, then, describes a double curve; the form of which the author has determined by analytical argument. His equations assign an exact valuation of the advantage possessed by an animal that elevates or removes the weight by drawing, and with the aid of a machine, in comparison with another that bears a similar weight by imme diate contact; (3.) and although these reasonings evince the indisputable situation of the weight relative to the animal which draws, yet they do not prove, as some have supposed, that the animal acts exclusively in consequence of his own weight; for the load drawn by horses in a carriage may greatly exceed including the weight of the carriage, that of the horses, which is evidently owing to the power of the wheel, or of any other purchase that might be used. (4.) (3.). A very essential object, which is almost ever neglected with regard to carts, waggons, and other vehicles intended to convey articles of merchandize, is the necessity of having the centre of gravity of the vehicle and the load coincident with that of the horse in the shafts. In the present distribution of the load, a portion of the effort is destined to functions that impede the drawing. Fashion, however, has luckily removed that defect in private carriages. It would be very easy, and by no means expensive to place the scantling above the axle-tree and the shafts below it, and to fasten the whole by means of pins and proper coins: according to this method it would be more easy to load the cart, which would not be so liable to overset. This low ering, however, of the bottom must have its bounds, according as the vehicle may be subject to deep ruts in bad roads, or in crossing fords and brooks. The elevation of the centre of gravity is prejudicial to the animal no less than inconsistent with the preservation of the wheels and roads. Perhaps it would be proper for the legislature to interfere, and to prescribe particular proportions which would be as interesting, in my opinion, as prevent ing the cuts and delvings occasioned by the fellies being too narrow, when the cart is heavily loaded. (4.) It is needless to observe that no exag gerated consequence could be deduced from this aphorism. Thus, in fixing the dimen sions of those machines attention must be paid: 1. To the causes which impede the progress of the wheels; 2. To the placing of the cen M. de Fossombroni, next considering the fatigue which affects the animal when loaded, observes, as the result of several scientific researches, "that in order to preserve animals "that carry weights over level ground equally "with those that go up hills or mountains, "it is indispensable that they should both "carry and draw at the same time." It is. evident that the value of this estimation increases or decreases according to the slope. From thence proceeds the necessity of loading more backwards the horses that go up hill, which method is not very injurious in descending, provided it be not carried to excess. M. de Fossombroni estimates the efforts of the animal, when drawing up hill, as being equal to those he must exert to keep a cart steady when going down hill. tre of gravity, as mentioned in the preceding note. The legislature having determined the width of the fellies of wheels, has greatly contributed to improvements in the building of carts, &c.; but a law for regulating the diameter of the wheels according to the weight of the load, would be equally conducive to the preservation of the animals, and to the conveniency of the carmen or waggoners. DESCRIPTION OF BUENOS AYRES, MONTE- THE late conquest of Buenos Ayres by the British arms, with its probable consequences, has excited in the public mind, a strong desire for better acquaintance with the nature, productions, and general character of that country. We are happy, therefore, in presenting to our readers [from the Spanish Universal Traveller] what we believe to be the latest communications published in Madrid on that subject, especially as there is every reason to depend on their authenticity. For this translation, with various other favours, we are obliged to a friend of the highest respectability. Buenos Ayres stands on the western bank of the great river Plata. The climate is the most favourable in the world. The whole territory of the present government was formerly under the jurisdiction of the Viceroy of Peru. In 1778, it was detached from this government, by which it has gained considerably but particularly by a royal ordinance of the same year, that declared the trade of this government to be free. In 1791, Spanish as well as foreign merchants, obtained permission to import negroes, also iron manufactures, and implements of husbandry; and To export all kinds of fruits. Thus agricul ture and population were encouraged, and accordingly they have considerably increased. From the same causes, in a short time, Buenos Ayres, on account of its uncommon fertility, may be considered as the granary of Spain and America. Another ordinance of April 10, 1793, allowed the exportation of salt provisions, and tallow free of duty. These ordinances relieved industry and commerce from their most galling fetters, and the prosperity of the country must annually increase. For, in these parts, nature only requires not to be impeded, and she will effect the rest. The province has an amazing extent of the most fertile fields; which are intersected in every direction by innumerable rivers and streams that fall into the Plata. The numbers of cattle, horses, sheep, and pigs, amount to millions. Salt is found in abundance, and there are plenty of harbours and creeks, where small vessels can be loaded with salt provisions, and carry them to other places. The rivers Plata, Paraguay, and Parana, with other small streams, offer the most desirable advantages; and the harbours of Buenos Ayres, Monte-Video, Maldonado, and the bay of Burragan, are spacious and secure. The whale and wolf-fish fisheries are very lucrative, and the chace in the interior of the country is no less profitable. For the tigers [properly, the janguara] are no less prized for their beautiful skins, than the ostriches are for their feathers. In the districts where the missionaries reside, cotton, hemp, and flax, are cultivated; and the province is not entirely destitute of gold mines, for gold is found in the neighbourhood of Maldonado and San Luis, about 200 leagues from the capital. We may judge of the immense herds of cattle by the number of skins annually exported to Spain. In 1792, 825,609 hides were exported from this province; without reckoning those sent to the Brasils in exchange for slaves. What are consumed in the country, and what are spoiled in the warehouses, are likewise excluded. The most correct idea of the prosperity and trade of the province may be deduced from the number of vessels entered inwards and cleared outwards, with their cargoes. In 1796, there arrived 35 ships from Cadiz, 22 from Barcelona, Malaga, aud Alfaquez; 9 from Corunna; 5 from Santander; 1 from Vigo; and another from Gijon. The value of these cargoes, consisting of national productions, amounted to 1,705,866 American Durres. The value of the foreign goods, on the same ships, amounted to 1,148,078 piastres. On the contrary, 26 vessels sailed for Cadiz; 10 for Barcelona, Malaga, and Alicant; 11 for Corunna; and 4 for Santander. These carried the value of 1,425,701 piastres in coined and uncoined gold. The ailver exported amounted to 2,556,304 pias- 24,436 fine skins; 46,800 arrobs (25 lb. each) of refuse 771 arrebs of Vicunna camel-sheep's 291 arrobs of guanaco ditto; and 2,264 arrobs of ordinary wool ; 11,890 goose-wings; 451,000 ox-horns; 3,223 cwt. of copper; 40 do. of tin; 2,549 tanned hides; 222 dozen of prepared sheep-skins; 2,128 cwt. of beef; and 185 cwt. of pork. and in national produce and goods to 24,703 piastres But it appears, that latterly, owing to the war and to the insecurity of trade, circumstances considerably changed for the worse. This is evident from the Spanish "Mercantile Courier" which contains a letter from Buenos-Ayres, Oct. 31, 1798; stating, that in the capital, as well as in Montevideo, there were about 3 millions of hides, which could not be exported, on account of liability to capture. Many European goods were entirely wanting, or had risen to an exorbitant price. There was a particular scarcity of European cloth. The deuiciency was supplied by woollen stuffs, either manufactured in the country, or imported from Peru. These stuffs were much prized, and about a million of ells were imported into Buenos-Ayres. The most approved come from the country of the Two vessels arrived from the Havannah. Chiquitos and Moxos. Brandy and Spanish They were laden with 22,159 arrobs of sugar; 239 casks of brandy; Total value 123,562 piastres. liquors were not to be procured at any price. Since that period the scarcity must have increased; yet the inhabitants endeavour to obviate it by an augmentation of interior industry. Thus in fact the province will be ultimately the gainer, and be induced to ao quire a knowledge and exercise of its own proper strength. Thus much of the province in general: of In return there sailed from the Havannah particular parts the work contains the follow 14 vessels, carrying 24,060 piastres in gold; 69,050 cwt. of beef; 252 dozen of prepared sheep-skins; 190 arrobs of wool; 280 goose-wings; Total piastres 160,110. ing information. Montevideo is the most considerable harbour in the Viceroyship, and at the same time the most advantageously situated. Don Bruno de Zabala was the first who settled here in 1731, with fourteen or fifteen families from Palma, one of the Canaries. Provisions are plentiful and cheap. As on one hand the means of subsistence are easily pro Two ships from Lima and Guayaquil cured, so on the other, the common people brought are inclined to indolence. Hence has arisen a vagabond tribe called ganderios [wanderers]. They live like gypsies, except stealing. They are either natives of Montevideo, or from the neighbouring villages. They are badly clothed; a coarse shirt, and still coarser coat are their whole attire. These and the furniture of their horses serve them for bedding, the saddle supplying the place of a pillow. They wander about with a small guitar, and sing songs either of their own composing, or what they hear from others. Love is generally the subject. Thus they travel through the country, and endeavour to amuse the farmers, who, in return maintain them during their stay, and provide them with horses when they have lost their own. This liberality ought not to appear strange, for horses are scarcely of any value. They rove wild in the immeasurable plains, and belong to any one who catches them. They are taken in snares, which are immediately drawn to |