I which I had a good opportunity of making, and which may presume be considered as tolerably correct, I should lay it down in 10° 50′ S. and 166° 10′ E. MARCH 3d, 1802. At 8 A. M. made several small low islands, distant about 6 or 7 miles: they are very dangerously situate, being level with the water, and if it were not for a few cocoa-nut trees growing on them, it would be impossible to see them 3 leagues off, on the clearest day. They lie in a N W and S E direction, about 7 leagues long; and are entirely surrounded with. rocks. A reef extends from the N W part into the sea about 6 miles, over which the sea breaks very high: there are but very few dry spots on the whole of them; they consist of white sand and coral. I make the northern extreme to lie in 9° 55′ N. and the southern in 9° 38′ N. Longitude of the middle of the shoal, from observations of sun and moon, 161° 26' E. SEPTEMBER 7th, 1802. At midnight made a shoal not twice the ship's length off, and steering right for it; immediately wore, and stood to the NW till day light; then stood to the S E, in order to survey the shoal. At 9 A. M. made the S W part, distant about S miles, and run along the N E part of it at the distance of one mile, or a mile and a half: it runs about N E and S W 16 or 18 miles in length, and about 1 in breadth; the NE part is the broadest, and on this part was the only dry spot I could see from the mast head. Some large drift-wood lying on it, had much the appearance of black rocks. It is a very dangerous shoal, and can not be seen until you are very near it. From good observed distances of the sun and moon, which I had the same afternoon, and good meridian altitudes that day and the day after, when in sight of the shoal, I have been able to ascertain its situation with tolerable correctness viz: The S W. extreme, Lat. 2 52 N. Long. 131 07 E. These are all in the usual course to and from China, of ships going round New Holland, and returning by the eastern passage. No. XIX. FIRST Report of Benjamin Henry Latrobe, to the American Philosophical Society, held at Philadelphia; in answer to the enquiry of the Society of Rotterdam, "Whether any, and what improvements have been made in the construction of SteamEngines in America ?” 66 Gentlemen, Philadelphia, 20th May, 1803. THE Report due from me to the Society, in consequence of the enquiry made by the Society of Rotterdam, as to the improvements made in America, in the construction of steamengines, would have been laid before you at a much earlier period, had it not been my wish to submit several American alterations in the construction of steam-engines, which promised to be very valuable improvements, to the test of experience: and this delay has not been without its use; for it has been discovered that some of our innovations, the theory of which appeared to be very perfect, have proved extremely deficient in practical utility. In this first report I will therefore confine myself to such improvements as have had a fair trial, in engines actually at work. Steam-engines, on the old construction, were introduced in America above 40 years ago. Two, I believe, were put up in New-England before the revolutionary war; and one, (which I have seen) at the copper-mine on the river Passaick, in New-Jersey, known by the name of the Schuyler-mine. All the principal parts of these engines were imported from England. With the Schuyler-mine engine, Mr. Hornblower, the uncle of the younger Hornblower, who is well known as a skillful and scientific engine-builder, and whose calculations on the power of steam are extremely useful, came to America. He put up the engine, which at different times has been at work during the last thirty years, and which, notwithstanding its imperfect construction, and the faulty boring of its cylinder, effectually drained the mine. During the general lassitude of mechanical exertion which succeeded the American revolution, the utility of steam-engines appears to have been forgotten; but the subject afterwards started into very general notice, in a form in which it could not possibly be attended with much success. A sort of mania began to prevail, which indeed has not yet entirely subsided, for impelling boats by steam-engines.-Dr. Franklin proposed to force forward the boat by the immediate action of steam upon the water. (See his Works). Many attempts to simplify the working of the engine, and more to employ a means of dispensing with the beam, in converting the Libratory into a rotatory motion, were made. For a short time a passage-boat, rowed by a steam-engine, was established between Bordentown and Philadelphia: but it was soon laid aside. The best and most powerful steam-engine which has been employed for this purpose, excepting perhaps one constructed by Dr. Kinsey, with the performance of which I am not sufficiently acquainted, belonged to a few gentlemen of New-York. It was made to act, by way of experiment, upon oars, upon paddles, and upon flutter wheels. Nothing in the success of any of these experiments appeared to be a sufficient compensation for the expense, and the extreme inconvenience of the steam-engine in the vessel. There are indeed general objections to the use of the steamengine for impelling boats, from which no particular mode of application can be free. These are: 1st, The weight of the engine and of the fewel. 2d, The large space it occupies. 3d, The tendency of its action to rack the vessel and render it leaky. 4th, The expense of maintenance. 5th, The irre gularity of its motion, and the motion of the water in the boiler and cistern, and of the fuel-vessel in rough water. 6th, The difficulty arising from the liability of the paddles or oars to break, if light; and from the weight, if made strong. Nor have I ever heard of an instance, verified by other testimony than that of the inventor, of a speedy and agreeable voyage having been performed in a steam-boat of any construction. I am well aware, that there are still many very respectable and ingenious men, who consider the application of the steam-engine to the purpose of navigation, as highly important, and as very practicable, especially on the rapid waters of the Mississippi; and who would feel themselves almost offended at the expression of an opposite opinion. And perhaps some of the objections against it may be obviated. That founded on the expense and weight of the fuel may not, for some years, exist on the Mississippi, where there is a redundance of wood on the banks: but the cutting and loading will be almost as great an evil. I have said thus much on the engines which have been constructed among us for the purpose of navigating boats, because many modes of working and constructing them have been adopted which are not used in Europe. Not one of them, however, appears to have sufficient merit to render it worthy of description and imitation; nor will I, unless by your further desire, occupy your attention with them. The only engines of any considerable powers which, as far as I know, are now at work in America, are the following. 1st, At New-York, belonging to the Manhattan Water-Company, for the supply of the city with water. 2d, One at New-York, belonging to Mr. Roosevelt, employed to saw timber. 3d, Two at Philadelphia, belonging to the corporation of the city, for the supply of the city with water; one of which also drives a rolling and slitting mill. 4th, One at Boston, of which I have been only generally informed, employed in some manufacture. In my second report, I will notice the improvements made by the very ingenious Dr. Kinsey, who has erected, at New-York, an engine upon a new principle which is intended to be used in the supply of that city with water; should it on experiment, be found to answer the intended purpose. He has made other improvements in the construction of steam-engines, of which I shall also give you some account. Nor ought I to omit the mention of a small engine, erected by Mr. Oliver Evans, as an experiment, with which he grinds Plaister of Paris; nor of the steam-wheel of Mr. Briggs. 1st. The Manhattan company's engine at New-York, is upon the principle of Bolton and Watt's double engines, without any variation. It has two boilers; one a wooden one, upon the construction of those first put up in Philadelphia, the other of sheet iron, on Bolton & Watt's construction. The Hy-wheel is driven by a sun and planet motion, and the shaft works three small pumps with common cranks. 2d. Mr. Roosevelt's engine has all the improvements which have been made by the joint ingenuity of Messrs. Smallman & Staudinger, with the assistance of the capital and intelligence of Mr. Roosevelt; and which have also been adopted to the engines, belonging to the water-works at Philadelphia. 3d. The engines at Philadelphia, independently of these improvements, act also upon a pump, the principal of which, though not new, has never before, I believe, been used upon a large scale; and which is worthy of being particularly described. I shall now proceed to describe these innovations, for experience does not permit me as yet to call them all improvements, although I have no doubt, but that they will furnish hints of use to bring the steam-engine to greater perfection. 1st. THE WOODEN BOILER. Wooden boilers have been applied in America to the purpose of distilling for many years. Mr. Anderson, whose improvements in that art are well known, appears to have first introduced them in America. But it was found that the mash had a very injurious effect upon the solidity of the wood: for while the outside retained the appearance of soundness, and the inside that of a burnt, but hard surface, the body of the plank was entirely decayed. It was however still to be tried, |