the water thus obtained, is by the operation of its gravity below the surface under the stern of the vessel; whereas, in mine, the water is discharged at the stern, on the surface, and produces propulsion by the combination of the three following operations: 1st. By the effect produced by removing from the bows of the boat the pressure of a part of the water displaced by the gravity of the vessel. 2d. By increasing that pressure by the weight of the water discharged on the surface at the stern. 3d. By the re-action of the water when discharging, on the side of the trunk opposite to the discharging orifice. The union of these three forces gives motion to the vessel, and her speed will be in proportion to the quantity of water raised, and the velocity with which that operation is performed.―Thus it appears that the venerable Franklin was the first to originate this " negative" principle of the application of power, and the "rejection of its immediate use," as applied to navigation and the "opening of a new era in one of the most important arts yet practised by mankind,” (vide, Mr. Busby's Essay, page 14,) commenced in the decline of his long and highly useful life. "It would be impossible (continues Mr. Busby,) for me to detail the successive gradations of idea that led to the concep tion of a discovery, great in its consequences. Impeded by mental inertia, it came slowly at first, and with reluctance, but once in motion, it advanced with the accelerated impetus of truth, and bore conviction before it."-Astonishing! A Yankee with a "Catalogue of Schemes" before him, would not have taken half the trouble. Again, (page 16,) "Every attempt, therefore, not excepting my own, has heretofore been made on a false basisnamely, that of operating upon the water, with a view to benefit from the resistance of its inertia." Again, (page 20,)" It is a fact somewhat remarkable, that the idea of this 'negative' application of power seems never to have suggested itself either to the ancients or moderns; the Phonicians, the Egyptians, the Tyrians, the Carthaginians, and the Romans, had their biremes and triremes, &c. all mov. ing by operation against the inertia of the water. The Italian gondolas are still navigated on a similar principle," &c. &c. Why not tell us plainly the important truth that the ancients did, and the moderus do-ROW THEIR Boats, I will next notice Mr. Linaker:-He, in attempting to realize the doctor's ideas, exhibits a want of talent seldom found in a good practical mechanic. His experiments appear to me to be a series of blunders; his first method is precisely the one recommended by Dr. Franklin, and, as far as it goes, resembles mine. But instead of confining the water as I do, in a set of trunks adapted to that purpose, in such quantity as to make it equal to a solid substance, and then cause the engine to push inclined plungers against it, as firmly as a boatman would push against a wharf or pier-head, when putting off, and causing the vessel to recede from the water, as the boat does from the wharf, with a velocity equal to the whole force of the engine, a desideratum hitherto not deemed atlainable. Mr. Linaker operates upon the water as a yielding substance, by " drawing it in at one end of a tube and delivering it out of the other, by means of a lifting pump working horizontally.' Thus, besides the loss of power sustained by the yielding of the water, in Mr. L's. experiment, the progress of the boat was impeded by the resistance of the water ahead, into which the boat was advancing, operating against the bucket frame, in its forward motion, in proportion to its resisting surface, and the speed of the vessel-a sufficient cause for not pursuing this method any further.' 66 In his second method he proposes, as an improvement, to draw the water in at the stern instead of the bows of the boat, by means of a forcing pump in a perpendicular position, (an inclined one would have been better,) and by some arrangement of his valves, he has given Mr. Busby an opportunity to say, very truly, that it had "an effectual tendency to impede the boat's progress." 23 What else could have been expected! If Mr. Linaker had, in this last operation, employed more than one pump, of suitable dimensions, and placed in an inclined instead of perpendicular position, drawing in the water from the bows instead of the stern, and exhibited a me thod of operating on this water as on solid columns, in rotation, with the full force of the engine, I confess there would have been a strong analogy between such a plan and my direct application of power. How could Mr. Busby, who professes so much discernment, confound two plans so evidently different! I could go into many particulars, to show the difference between my plans, and those which Mr. Busby chooses to call analogous; but it would too much of an swell this article for an ordinary commurication-those who may feel desirous to investigate the subject, can examine my essay, and draw their own conclusions. Mr. Busby has also referred to the Repertory of Arts, of 1815, for a description "Air Engine patented about four years since in England." Although I have searched diligently that volume, and others that immediately preceded and followed it, I find no other allusion to the subject than an account of experiments made with condensed air, but not rarefied, which did not succeed for reasons already given in my essay. But as he says, the ingenious Mr. Murray, of Leeds, England," was engaged, for many years in similar pursuits, I take it for granted that the "Air Engine" alluded to, was like Mr. Murray's, and I find in Dr. Rees' Cyclopedia, under the article Steam Engine that this gentleman has obtained a patent for a new air pump, but (says the writer of the article) "as the ingenious inventor does not adopt it in the steam engines which he makes, we may presume it is not of great importance." Hence it clearly appears, that Mr. Murray's air pump was only intended as an improved auxiliary to the steam engine, and not an “Air Engine" as "a primum mobile," which Mr. Busby appears to consider it. Mr. Busby further states, that "many expensive experiments (some of which he witnessed) have been made in England under the superintendence of the first mathematicians and mechanicians, but finally the idea was abandoned." Now I hold him in candour bound to state, whether these were aerial experiments, with a view to improvements in aerostation, as the aeronaut M. Montgalfier seems to have been concerned in them, or such as relates particularly to my system. I want to know what kind of air these great men experimented with, whether common atmospherical air in its natural, compressed or rarefied state, and if condensed, how many atmospheres; if gases were employed, what kind, and under what peculiar circumstances; whether these gases were condensed or rarefied, when used, and whether they were expended; as in the case of steam, or alternately expanded and contracted, and not expended; and also, what kind of instruments or engines were employed, and what were the peculiar results. He witnessed them, probably recorded them, and doubtless possesses sufficient know ledge to unfold them. I must, however, give Mr. Busby credit for referring me to the "matters of record" alluded to, for I confess myself to have been a total stranger to them, and if he can give some others from his "Catalogue,” particularly if they can touch or be assimilated to my plans, he will in this respect confer an additional favour-the "zeal" of my friends cannot half so much help me. By the preceding account it would appear that the "negative" method suggested by Dr. Franklin, has not, hitherto, been put in practice; that my two "negative" modes of propulsion are similar in principle to his, though more perfect in their application, and made without having any previous knowledge of his suggestions; that Mr. Busby's method being similar to one of mine, though not quite as perfect, is of course precisely the same application of the doctor's principle, and was effected subsequent to his knowledge of this important fact, and that the wheel which I now employ, is a simple instrument, having found by experience that the compound wheel, such as Mr. Busby uses, was too bulky, and that according to a well known axiom in mechanics, that whatever was gained by its complication, one-third of it was lost by mere friction. Hence my present wheel having only six paddles instead of eight, the usual number, and being so circumstanced in its inclined position, as to admit the motion of the vessel to be reversed or suspended at pleasure, without stopping the engine, has an advantage his wheel does not appear to possess. As it respects my second and most perfect application of the "negative" principle, by means of instruments denominated plungers, operating upon the combined principles of the lifting and forcing pump, Mr. Busby has observed a profound silence. How far and with what justice he has by this procedure, denied this application of the doctor's principle, the surprising advantage he has ascribed to his own imperfect method, will, I trust, appear on reference to his essay; and with that intention, I am constrained to say to him, that "out of thy own mouth I will judge thee,"-Luke. "By the removal of the water from within the raceway, (says Mr. B.) the resistance (to the boat's motion) has been entirely removed, while the external pressure beneath the inclined plane of the raceway remaining unimpaired, urges it forward," page 17. Again, “the object is now obviously to remove the water from within the raceway as freely as possible-the action of the water wheel will then reduce the resistance ahead while the pressure astern remains undim, ished, motion must ensue," page 19. Again, "the application of this principle is simple and expeditious. Suppose it were required to make any vessel, say the Chancellor Livingston, travel fifteen miles per hour, ascertain what power applied from the land would be necessary to produce the desired effect; then make the raceway and paddles of such dimensions as to operate upon a column of water, whose lateral pressure against the paddles would be equal to that power, and the object is immediately attained," page 20. Again," supported as I am, by the fundamental laws of nature, tested by experiment, will I venture to call public attention to a matter fraught with consequences of high importance," page 21.Now I would simply ask Mr. Busby what kind of difference it would make, whether the water was removed from the bows of a vessel by a simple or compound wheel, or by a pair of suitable pumps? Pumps, we know, are generally preferred to all other instruments for raising water-they ART. 5. LITERARY AND SCIENTIFIC INTELLIGENCE. DOMESTIC. HERE has recently been established ler, James Tallmadge, jun. Robert Bogardus. Pierre C. Van Wyck, John Pin city, society : mises to render itself of great public utility. It is entitled "the New-York Corresponding Association, for the promotion of Internal Improvements." The objects of the institution are thus stated : "This association has for its object the acquisition and diffusion of all useful intelligence connected with the inland trade and navigation of the country. Its founders have indulged the hope, that by opening an extensive correspondence with gentlemen of the first distinction throughout the union, and by imbodying and sending forth, in a comprehensive form, the information which might be thus acquired, great and permanent benefit could be rendered to the American people, and much incitement given to that noble and munificent spirit of enterprise, in relation to internal improvements which now distinguishes every quarter of the United States. Officers of the Association. cation. Thomas Eddy, Chairman; William Bayard, Theodorus Bailey, Sylvanus Mil H. Bowne. Charles G. Haines, Corresponding Secretary. Henry Post, jun. Treasurer.” The following are the queries contained in the circular issued by the society: "1. What roads or canals have been opened in your county, or in your state, to encourage internal trade and navigation? "2. What roads and canals are now opening? "3. What roads or canals are contemplated? "4. What roads or canals might be opened to promote internal trade and navigation, and to what probable extent would any such improvements effect these two sources of industry and wealth? 5. What is the extent, character, and course of trade in your immediate vicinity?" The following is the circular of the College of Physicians and Surgeons of the University of the state of New-York. City of New-York, August 18th, 1818. Inquiries being frequently made, by persons resident at a distance, relative to the course of studies and requisites for graduation, in the College of Physicians and Surgeons of the University of New York, as also concerning other matters interesting to the students who resort to this school of medicine, the trustees of the college, with a view of removing the inconvenience of answering so many individual applications, and of gratifying those whom it may concern, have ordered the present Circular to be published for general information. The College opens, annually, on the first Monday in November, and the several courses begin, successively that week, after the introductory lectures of the respective professors. The session closes the last day of February. Lectures in the Forenoon. Theory and Practice of Physic, by Dr. Hosack, from nine to ten o'clock, daily. Principles and Practice of Surgery, by Dr. Mott, from ten to eleven, daily. Anatomy, Physiology, and Surgery, by Dr. Post, from eleven to twelve, daily. Lectures in the Afternoon. Natural History, including Mineralogy, Botany, and Zoology, by Dr. Mitchill, from one to two, daily. Chemistry and Materia Medica, by Dr. M.Neven, from five to six, daily. Obstetrics, and the Diseases of Women and Children, by Dr. Hosack, from four to five, on Mondays and Thursdays. Clinical Practice of Medicine, by Dr. Hamersley, from four to five, on Wednesdays and Saturdays. Institutes of Medicine, and Forensic Medicine, by Dr. Francis, from four to five, on Tuesdays and Fridays. Graduation. It is expected that a candidate for graduation shall have attained the age of twenty-one years. On or before the first of February, the canditate shall make known his name and intention to one of the professors, by whom he will be informed of the time and place of examination. This first examination is by the board of professors only; it is private and confidential. A second examination is held before the board of trustees, to whom, on this occasion an appeal lies, and before whom there is offered an opportunity of redress, if a candidate thinks himself in any wise aggrieved. The names of those who have been approved by the trustees are forwarded to the regents of the University,. who return an equal number of diplomas, under the signature of the chancellor. They are afterwards signed by the president of the College and the professors. By the 20th of March, the candidate shall deliver to one of the professors a dissertation on some medical subject. He is publicly examined on the same, in the College Hall, the first Monday in April, and may publish, with the approbation of one of the professors, either in the English, French, or Latin languages. The degrees are conferred by the president the next day, at a public Com mencement. From the provision thus made, it will be seen that the various courses of lectures delivered in the College are so arranged, as to constitute a complete system of medical education. The board of trustees, however, think it incumbent on them to state, that it has been their unremitted endeavour to increase, as far as practicable, the means of instruction, and to render the advantages enjoyed by the College, at least equal to those of any other similar establishment in the United States. The anatomical museum, of large extent, has been augmented by some rare and valuable preparations, and very important additions have been made to the chemical apparatus and laboratory. The cabinet of natural history has also been greatly enriched by numerous specimens, native and foreign; and in the illustrations of the geology and mineralogy of the American states, is peculiarly rich. Measures have recently been adopted by the trustees in order to provide a library for the students of the University. It is proper further to state, that although the most liberal and extensive system of medical and philosophical instruction has thus been provided, the expense of education to the candidate for medical honours is not increased beyond that of any other College in the union, as the courses are not made indispensably necessary for graduation, and the student is at liberty to attend any course or courses he may think expedient: the professors insist upon the attainments of the candidate, and not upon the number of courses, nor the number of years he may have attended at the University. The trustees confidently believe their plan of education satisfactory, and they indulge the hope that nothing will be wanting to fulfil the just expectations and liberal views of their patrons, the honourable the legislature, and the regents of the University of New-York. By order, SAMUEL BARD, M. D. President. JOHN W. FRANCIS, M. D. Registrar. We understand that Mr. GEORGE FREDERIC BUSBY intends giving, in the course of the present month, in this city, a public Lecture on Poetical Literature. The productions of Mr. Moore and Lord Byron will, we learn, constitute the subjectmatter of the discourse, which will be accompanied by illustrative readings from the most admired effusions of those fascinating writers. Mr. Busby's recitative powers are, we are told, peculiarly vivid and discriminating; and we have no doubt that in the composition of the Lecture his literary talents will be displayed to advantage. The third half-volume of Mr. Delaplaine's Repository is in a state of considerable forwardness, and will shortly be put to press. As the object of this work is to perpetuate the glory and virtues of those illustrious men who fought and counselled for the liberties of America, we cannot avoid recommending it warmly to the patronage of the public. Mr. Delaplaine has, we understand, been anxiously solicitous to render the present number worthy of the support we trust be will receive, and, by securing the assistance of the most eminent graphic and literary talents in the country, justified bis claims to public approbation. At the late annual commencement of Union College in this state, the degree of LL. D. was confered on DAVID HOBACK, M. D. F. R. S. Dr. HosACK's new System of Nosology is nearly printed, and will be published early in October next, in one volume, octavo. The Board of Trustees of the College of Physicians and Surgeons of the University of New-York, have recently adopted measures for the purpose of establishing a Medical and Philosophical Library for the more immediate advantage of students who resort to that school for instruction. E. J. COALE, of Baltimore, has recently published a translation of Jacobsen's LAWS OF THE SEA. The following notice of the work is taken from the Hamburg Journal of Politics and Literature: "We refer the attention of the public to a work of high interest, entitled, "Laws of the Sea, in relation to Maritime Commerce during Peace and War, by Frederick J. Jacobsen, Advocate, Altona. 1815.' Most of our readers will not fail to recollect the author's former treatise on the practical sea-laws of the English and French in relation to neutral property. The extensive importance of the contents, and the excellence of the execution of that work, were universally acknowledged. The author's present work, of equal excellence and merit, but of higher import, is presented at the favour able moment of a general pacification, and must excite the attention of all mari time powers, in proportion to the unexampled extent to which commercial rights were prostrated during the late eventful wars, and the desire of regene rating a system at once so perfect and universally in force as the Consolato del Mare. By the work before us, the author has acquired the praise of having attempted this system on the most solid foundation. Without doubt it is already in the hands of all our readers to whom the German language is familiar; and we indulge a hope ere long of seeing it at least in the English and French. Commercial Law has never before been treated with more perspicuity and system, and compiled from such a variety of authentic documents, and references to judicial authorities-no author before has enriched the subject with more just remarks drawn from extensive professional experience, and an universal acquaintance with the works of the later English and other European systems of legal ju risprudence-not only as it is at this day developed, but also as the principles of equity and justice, and the general interest of commercial nations require it to be established. We are assured we do not say too much, but merely anticipate what a more circumstantial review will confirm and support. Inestimable advantages must arise to maritime commerce, from an observance by all the maritime powers of the principles upon which the work is established; for the neglect and disregard of them has produced incalculable mischief. The intelligent author, in a general review of maritime law, has brought together with unwearied indus try, with critical learning and profound judgment, all that might be deemed useful and applicable to the subject from practical jurists, among the Italians; French, English, Dutch and Germans, and particularly from his long professional experience, and a correspondence with men learned in the subject of maritime jurisprudence. The work merits the consideration of all commercial governments, and should be in the possession of every respectable merchant and mariner. Above all, the decisions of the great Admiralty Judge, Sir William Scott, are herein adverted to, and the grounds of his decisions estimated according to their high value. The author's own opinions and wishes, which are advanced with a commendable modesty, are as just as they are philanthropic. If, as we conceive, wars are inevitable, may his labours be |