country, and it seems only to require a few successful experiments, to diffuse a knowledge of the advantages of this means of, in effect, destroying space, before we realize the benefits of it. Dupin has attentively examined these works in England where they have grown up within a few years, (since 1786). The rail ways used in England are of two kinds, called tramways or plate ways, and edge ways. The tramways consist of straight pieces of iron, plane on the surface, with a flanch or ledge rising on one side, both to increase the strength of the way, and to direct the carriage. The edge ways on the contrary consist of deep bars, the upper edge being rounded, and to this is adapted a groove on the periphery of the wheels like the groove of a pully. Dupin remarks, that the former have the great disadvantage of retaining the earth, the sand, or even the flints and small stones which may fall on them; thus augmenting considerably the resistance to the passage of the wheels. From this serious evil the edge ways are free. The greatest difficulty in the execution of rail ways, is in laying them in a manner to insure the preservation of the direct line first given to them; to effect this object the present method is to lay them immediately on transverse blocks of cast iron. Our author says that on a perfectly constructed horizontal rail way, an excellent horse can draw ten tons, and he cites an instance, at the city of Glasgow, where a rail way is used in a very sloping situation, (degrees not stated,) up which a good horse can draw three tons; and work daily drawing up a load of one and an half tons.

M. Dupin has gone carefully through with an account of the canals, harbours, docks, and lighthouses of Great Britain, and given a description of several of the finest bridges; both those constructed with arches, and those of suspension. All these are illustrated by engravings worthy of the works which they represent. We take from his account of bridges, a popular description of Sunderland bridge, as one of the finest, although not one of the latest, works of its kind.

"This bridge is of a single iron arch of 236 feet span, and 98 feet from the central voussoir to the level of the sea (at low water). Nothing can be more striking than the view of the two towns, with the bridge that unites them. This majestic arch, sketched as it were in the heavens, and which permits large vessels to pass under its vault with their topsails spread; while enormous carriages are crossing its aerial summit. The immense number of vessels taking or discharging cargoes on both sides; the running of the water-the various works established on the banks of the river-the rail ways

which conduct to the landing place carriages loaded with coal and lime stone; and the two cities which crown this magnificent amphitheatre. Such a picture presents the most extraordinary combinations between the accidental beauties of nature, and the works of an ingenious and powerful industry." In closing this miscellaneons paper, we may notice as amongst the greatest faults of M. Dupin, his ingenuity, which furnishes him so readily with sufficient causes for every event or step in the progress of improvement, that he always seems desirous of attributing every thing that happens, to some deep design, or the influence of some peculiar system; which indeed might have produced it, though that it actually has done so, we can never be perfectly sure. The various lights in which he sees any position that he fixes upon, and the profusion of materials which he can command for its defence, often prove a source of weakness to him, or rather enables one, who may have the disposition, to cross his purpose. An instance of this kind is furnished in our first quotation from his work; where, taking it as a fact that the invention of gun powder has rendered war less sanguinary, he relates the circumstances of ancient and modern battles, which show the former to have been more destructive than the latter; but, pursuing his inquiry into the general policy of nations, he tells us, that in proportion as battles are more bloody, wars will be undertaken with more unwillingness, and contending nations will be more ready for peace: a very substantial reason, surely, for preferring the ancient and more destructive weapons and mode of warfare. The faults of his work are, however, trifles compared with its merits; our good opinion of it has increased luring the preparation of this paper. We should hope, were It not so scarce a book, that many of our readers would procure it, for we assure them that if they have found our short account of it tedious; they will not find the original work so.

In turning from the iron and stone architecture of Europe, to our own country, we connect very strongly with the works erected here, the idea of decay to which they are all rapidly hastening. Our bridges are of wood and our houses and public edifices contain in their structure so much of the same perishable material, that they hardly outlive the generation that rears them. Amongst the other causes which have contributed to this state of things, the want of capital and the consequent high rate of interest has been one of considerable magnitude. In estimating the probable yearly expense of maintaining any projected work, whether for public or private convenience, the interest of the capital originally invested as

well as the amount of wear and decay, is taken into the account and such materials are chosen as redcce this sum of expense to the lowest possible degree: we may conclude therefore that the late depreciation of the rate of interest, rendering the use of more solid materials common, will aid the cause of civil architecture in the United States.

General Entelligence.

COMET OF 1823.

To the Editors of the Boston Journal.-I observe in the Boston Journal of June, the Elements of the comet of 1823, by several different gentlemen. They agree generally with those communicated by me, as well as could be expected, considering the means I possessed for making observations. The place of the perihelion, however, appears very different from mine. As but few, if any, will understand the reason of this, it will generally be thought that I have committed an error, unless it is explained.

In all the elements that I ever saw published before these last, the place of the perihelion on the orbit has been given as it was in mine. But in these last of yours, the distance of the perihelion from the node is given, and the sign-before it to show that it is back or west of the node.

The elements will be given by mine so as to correspond with those, if from 302° 37′ 41′′ the place of the node, we subtract 271° 39' 11" the place of perihelion on the orbit. This gives - 30° 58′ 30′′, which corresponds pretty nearly with those from the Philosophical Magazine.

Waltham, Aug. 19, 1824.

I am &c.

WARREN COlburn.

Cabinet of Minerals at Cambridge.-The liberality of several gentlemen of Boston, and their desire to promote the study of Mineralogy and Geology in this vicinity, have lately been displayed in the purchase of an extensive and valuable collection of minerals, which they have presented to the University at Cambridge.

This collection is now added to that presented by Andrew Ritchie Esq. and together with the specimens formerly transmitted by the French Government, and the late Dr Lettsom with the additions made by Dr Waterhouse, will constitute one of the most complete and valuable mineralogical cabinets in the United States.

The collection embraces (with the exception of a very few of the rarest substances) all the late discoveries, and many of those specimens, the localities of which are exhausted, and many of which are now rarely met with even in the large collections of Europe. The suite of Ores is peculiarly rich, as is likewise the volcanic department; and the gems and precious stones are numerous. The specimens are all well characterised, and the crystallizations are remarkably fine. This collection is arranged in the spacious room formerly used as the Commons Hall, being 454 feet in length, 361 feet wide, and 173 feet high.

The specimens are placed in cases with glass doors against the walls of the room, which to the height of ten feet are completely covered by them; a large proportion of the most beautiful specimens are arranged upon eight glazed tables, and the residue in nearly 200 drawers.

One of the tables is appropriated to the EXTERNAL CHARACTERS of mineral substances, on which are disposed the most distinctly characterised specimens, illustrating all the technical terms of the science, the different varieties of colour, of fracture, lustre, transparency, hardness, &c. &c. To these succeed the most perfect crystals illustrating the primary forms of Werner, and Haüy, the modifications of these forms, and the effect of truncations, bevelments, &c.-A suite of models of crystals, in wood, terminates this first division of the cabinet.

The second division is the systematic arrangement of the different substances according to their chemical composition; this method has been adopted as it is intended to combine the instruction in chemistry with mineralogy.

The third division comprises the Geological part of the collection; in this the rocks are arranged in the relative order in which they are presented to us by nature, and in connexion with each are seen the minerals composing the rock, and those which are more or less accidentally present in it, together with the metallic ones and fossil remains.

The fourth division is Geographical, commencing with the mineral productions of the United States, arranged according to States.

The last division is intended to embrace all the products of the Mineral kingdom employed in the Arts and Manufactures, in their natural state, and in the different stages of preparation. This department is one of peculiar interest and importance in this country, and can only be rendered complete by the liberality of artists and manufacturers, who, it is hoped, will not be backward to transmit to the University such specimens as

will best illustrate the different stages of all the processes connected with each substance. Thus here will be seen the different ores, as when first taken from the earth, and the same in all the degrees of purification &c.--the clays in all the stages of manufacture-the substances used in colouring, in the manufacture of glass, &c. &c.

Mineralogists throughout the country, it is hoped, will avail themselves of the permission granted by the Corporation of the University to exchange duplicate specimens.

AMERICAN GEOLOGICAL SOCIETY.

THE annual meeting of this society was held at New Haven Sept 8th. The following gentlemen were elected officers for the ensuing year

The following gentlemen were elected members of the Society.-Henry Seybert, Philadelphia; John Griscom, New York; Dr E. Emmons, Chester, Mass; S. J. Andrews, New Haven; G. T. Bowen, Philadelphia; Lieut. H. Webster,