Rouen, where the Louxor was inade fast before the quay d'Har court. Here we must remain until the autumnal rains raise the waters of the Seine, and permit us to transport to Paris this pyramid, the object of our expedition." This event has since happened, and the column safely erected on its pedestal.

American Steamers.

The following extract from a late London work, "Stevenson's Engineering in North America," may not be uninteresting to most of our readers :

“The steam navigation of the United States is one of the most interesting subjects connected with the history of North America; and it is strange that hitherto we should have received so little information regarding it, especially as there is no class of works, in that comparatively new and still rising country, which bear stronger marks of long-continued exertion, successfully directed to the perfection of its object, than are presented by many of the steamboats which now navigate its rivers, bays, and lakes.

"It would be improper to compare the present state of steam navigation in America with that of this country, for the nature of things has established a very important distinction between them. By far the greater number of the American steamboats ply on the smooth surfaces of rivers, sheltered bays, or arms of the sea, exposed neither to waves nor to wind; whereas most of the steamboats in this country go out to sea, where they encounter as bad weather and as heavy waves as ordinary sailing vessels. The consequence is, that in America a much more slender built, and a more delicate mould, give the requisite strength to their vessels, and thus a much greater speed, which essentially depends upon these two qualities, is generally obtained. In America, the position of the machinery and of the cabins, which are raised above the deck of the vessels, admits of powerful engines, with an enormous length of stroke being employed to propel them; but this arrangement would be wholly inapplicable to the vessels navigating our coasts, at least to the extent to which it has been carried in America.

"But perhaps the strongest proof that the American vessels are very differently circumstanced from those of Europe, and therefore admit of a construction more favorable for the attainment of great speed, is the fact that they are not generally, as in Europe, navigated by persons possessed of a knowledge of seamanship. In this country steam navigation produces hardy seamen; and

British steamers being exposed to the open sea in all weathers, are furnished with masts and sails, and must be worked by persons who, in the event of any accident happening to the machinery, are capable of sailing the vessel, and who must therefore be experienced seamen. The case is very different in America, where, with the exception of the vessels navigating the lakes, and one or two of those which ply on the eastern coast, there is not a steamer in the country which has either masts or sails, or is commanded by a professional seaman. These facts forcibly show the different state of steam navigation in America,—a state very favorable for the attainment of great speed, and a high degree of perfection in the locomotive art.

"The early introduction of steam navigation into the country, and the rapid increase which has since taken place in the number of steamboats, have afforded an extensive field for the prosecution of valuable inquiries on this interesting subject; and the builders of steamboats, by availing themselves of the opportunities held out to them, have been enabled to make constant accessions to their practical knowledge, which have gradually produced important improvements in the construction and action of their vessels. But on minutely examining the most approved American steamers, I found it impossible to trace any general principles which seem to have served as guides for their construction. Every American steamboat builder holds opinions of his own, which are generally founded, not on theoretical principles, but on deductions drawn from a close examination of the practical effects of the different arrangements and proportions adopted in the construction of dif ferent steamboats, and these opinions never fail to influence, in a greater or less degree, the built of his vessel, and the proportions which her several parts are made to bear to each other.

"The voyage between Albany and New York is now generally performed in ten hours, exclusive of the time lost in making stoppages, being at the astonishing rate of fifteen miles per hour. They have effected this great increase of speed by constantly making experiments on the form and proportions of their engines and vessels,-in short, by a persevering system of trial and error, which is still going forward; and the natural consequence is, that, even at this day, no two steamboats are alike, and few of them have attained the age of six months without undergoing some material alterations.

"These observations apply more particularly to the steamers navigating the eastern waters of the United States, where the great number of steamboat builders, and the rapid increase of trade, have produced a competition which has led to the construction of

a class of vessels unequalled in point of speed by those of any other quarter of the globe. The original construction of most of these vessels has, as already stated, been materially changed. The breadth of beam and the length of keel have in some vessels been increased, and in others they have been diminished. This mode of procedure may seem rather paradoxical; but in America it is no uncommon thing to alter steamboats by cutting them through the middle, and either increasing or diminishing their dimensions as the occasion may require. It is only a short time since many of the steamboats were furnished with false bows, by which the length of the deck and the rake of the cutwaters were greatly increased. On some vessels these bows still remain; from others they have been removed,-subsequent experiments having led to the conclusion, that a perpendicular bow without any rake is best adapted for a fast-sailing boat. When I visited the United States in 1837, the 'Swallow' held the reputation of being one of the two swiftest steamers which have ever navigated the American waters, and this vessel had received an addition of twenty-four feet to her original length, besides having been otherwise considerably changed Before these alterations were made on her, she was considered, as regards speed, to be an inferior vessel.

"The inferences to be drawn from these facts are, that the great experiment for the improvement of steam navigation, in which the Americans may be said to have been engaged for the last thirty years, is not completed, and the speed at which they have succeeded in propelling their steam-vessels may yet be increased; and also that, in the construction of their vessels, they have been governed by experience and practice alone, without attempting to introduce theoretical principles, in the application of which, to the practice of propelling vessels, by the action of paddle-wheels on the water, numerous difficulties have hitherto been experienced.

"There are local circumstances, connected with the nature of the trade in which the steamboats are engaged, and the waters which they are intended to navigate, that have given rise to the employment of three distinct classes of vessels in American steam navigation, all of which I had an opportunity of sailing in and particularly examining.

"These steamboats may be ranged under the following classification:-First, those navigating the Eastern waters. This class includes all the vessels plying on the river Hudson, Long Island Sound, Chesapeake and Delaware Bays, and all those which run to and from Boston, New York, Philadelphia, Baltimore, Charles ton, Norfolk, and the other ports on the eastern coast of the country, or what the Americans call the sea-board. Second, those

navigating the Western waters, including all the steamers employed on the river Mississippi and its numerous tributaries, including the Missouri and Ohio. Third, the steamers engaged in the Lake navigation. These classes of vessels vary very much in their construction, which has been modified to suit the respective services for which they are intended.

"The general characteristics by which the Eastern water boats are distinguished, are, a small draught of water, great speed, and the use of condensing engines of large dimensions, having a great length of stroke. On the Western waters, on the other hand, the vessels have a greater draught of water and less speed, and are propelled by high-pressure engines of small size, worked by steam of great elasticity. The steamers on the Lakes, again, have a very strong built and a large draught of water, possessing in a greater degree the character of sea-boats than any of those belonging to the other two classes. They also differ in having masts and sails, with which the others are not provided.

"The steamboats employed on the Hudson river are the first, belonging to the class of vessels navigating the Eastern waters, of which I shall make particular mention.

"The shoals in the upper part of the river, produced by the Overslaugh, have rendered it necessary that the steamboats employed in its navigation should have a small draught of water. The great trade of the river, and the crowds of passengers which are constantly travelling between New York and Albany and the intermediate towns, have also led to the adoption of separate lines of boats, one for towing barges loaded with goods, and another devoted exclusively to the conveyance of passengers. The attainment of great speed naturally became an important desideratum in the construction of the vessels employed in carrying passengers; and the success which has attended the efforts of the steamboat builders to produce, vessels, combining swiftness with efficiency and perfection of workmanship, is truly wonderful, and in the highest degree creditable.

"The hulls of almost all the American steamboats, especially those which ply on the rivers, carrying no freight excepting the luggage belonging to passengers, are constructed in a very light and superficial manner. They are built perfectly flat in the bottom, and perpendicular in the sides; a cross section in the middle of the vessel, having the form of a parallelogram, with its lower corners rounded off. This construction of hull is well adapted to a navigation where the depth of water is small, and the attainment of great speed is an object of importance, as it ensures a smaller draught of water, and consequently affords less resistance to the

motion of the vessel than any other mould which has an equal area of cross section below the water line; but vessels built in this way, without a deep keel, having no hold of the water, are not wel. adapted for making sea voyages, as they cannot resist the effect of the wind, which causes them to make lee-way. It is only the great breadth of the paddle-wheels and power of the engines which enables the American boats to move steadily through the water. The breadth of the paddle-wheels is, in fact, so much additional breadth added to the beam of the vessel; for the reaction of the float-boards striking the water tends, in some measure, to counteract any tendency that the vessel may have to roll, which would otherwise be very apt to take place in the American steamers, where the machinery and boilers are placed above the level of the deck. There is no rolling motion felt in these fast boats. The rectilineal motion, however, is by no means regular. Every stroke of the engine produces a momentary acceleration in the speed, giving rise to a see-saw motion, resembling that of a row-boat, in which the impulse produced by every stroke of the oars is distinctly felt.

"In the American steamers the keel generally projects from two to six inches from the bottom of the hull, and is level from stem to stern. Its principal service, when the projection is so small, consists in strengthening the hull. The deck-lines of the hull, in general, begin to fall in at a distance of a few feet from the middle of the vessel. They approach each other with a gentle curve, towards the stern and bow, where they meet, and are connected by the stern-post and cutwater of the vessel. The cutwater is generally perpendicular; and the sides of the vessel, diverging from it, present a very acute angle to meet the resistance offered by the water.

"The speed of the American steamboats has excited consider. able wonder in this country; and some people have been inclined to doubt the accuracy of the statements that have frequently been made regarding the extraordinary feats performed by them. Fast sailing is a property which is not possessed by all American steamboats; but that a few of those navigating the river Hudson and Long Island Sound perform their voyages safely and regularly, at a speed which far surpasses that of any European steamer hitherto built, every impartial person, who has had an opportunity of seeing the performances of the vessels in both countries, must be ready to admit.

"Some difficulties at present exist, which preclude the attainment of more than an approximation in ascertaining the maximum rate at which the steamboats on the Hudson are capable of being