Imágenes de página
PDF
ePub

contented, and happy. This institution is as honorable to the French nation, as the hospitals of Chelsea and Greenwich are to the English.

The Jardin des plantes, in which is situated the national museum of natural history, was one of those places which interested me the most. In this spacious garden are hot-houses and green-houses, containing all the trees, plants and shrubs that could be procured from various parts of Europe, Asia, Africa and America; and a charming room for botanical students. At another part of the garden is the national menagerie,where beasts enjoy much more liberty and a better air than they can possibly have in the tower of London. Each animal has a spacious apartment, and the collection is very good. There is also a great variety of curious birds. In another spot is a monument erected to the memory of Rousseau. The museum consists of a spacious room and two smaller apartments, in which are arranged, with the greatest taste, natural curiosities of every description. A botanical student whom we met by chance in the garden, observing we were strangers, kindly devoted an hour or two to explain to us every thing most worthy of attention.

"La politesse Française !" The manufactory of tapestry is well worth seeing. It is said to require the practice of twenty years to become proficient in the work, and the smallest piece there had occupied seven men nine years to bring it to completion; but when done, the beauty is exquisite. The artists work at the back of the frame, while the subject is traced on the front. I saw the judgment of Solomon completed; also, the miracle of the fishes, and Esther appearing before the king in behalf of Mordecai; also some representations of ancient battles. At that time they were employed, about a piece for the Thuilleries; the subject was the death of Dessaix.

The national library can scarcely be seen in two or three visits. There is a suite of rooms, very spacious, filled with valuable manuscripts, and ancient and modern publications in all languages. There are two immense globes, which Occupy two stories (the intermediate floor being pierced to receive them), of which I dare say you have heard frequent mention. There are public lectures twice a week on geography and astronomy. And persons, free of expense, are admitted into the library to read and study. A privilege, I believe rather difficult to be obtained in London, on such a liberal

plan. It is certainly a great pity this valuable building should be situated immediately opposite the opera house, which has been already twice burnt, and the books and edifice, I have understood, were saved almost by a miracle. And now I am so near the opera, and having given you, in an unconnected manner, an account of those places which I recollect, I shall observe that I was much entertained with the performances at the opera, and being in a language I could understand (French) I was as much gratified as I ever should be at a theatre, because I am not extremely partial to public places. The dancing, in which the French are known to excel, was really wonderful, and the effect of the stage splendid, though a spacious house must naturally look dismal from the lights being so disposed as to reflect only on the stage and performers. I approve of this plan, for surely that ought to be the attracting object, any other place might do as well for the purpose of gazing, or be ing gazed at, a fashion much adopted by the English at their places of entertainment. I will confess I have also received peculiar pleasure in seeing the tragedies of Racine, in which Talma and Mademoiselle Duchesnois were very great. The Theatres Comiques, did not interest me greatly, in most of their ludicrous pieces a John Bull was introduced, the character was always rendered either extremely ridiculous, or otherwise derogatory to the English, and however I may take the part of the French, I always felt hurt when my countrymen were represented in an unfavorable light.

I went one morning with Mr. Priestly to the Pantheon; there were many monuments to the memory of illustrious characters, but most of them so much destroyed, and the place then in such confusion, that I retain but an imperfect idea of the whole. In a letter which I received some time since from Paris, they

say

"I wish we could now take you to many of these places, the sight of which afforded you pleasure when with us, they would now greatly delight you, as all are arranged in the most perfect order."

The character of the French has been too often pourtrayed by competent judges of human nature, for me to presume to offer more than my real opinion of them, not desiring that others should form from that any decided idea of their character, which I consider to be (notwithstanding you affirm that I think them superior to every other nation) a compound of contradiction. They are mean, yet extravagant. Polite, yet rude. Fearful of offending,

yet apt to wound the feelings. They welcome strangers, and yet are themselves strangers to the true rites of hospitality. Prémature and warm in their friendship, yet not generally to be confided in. It would be ingratitude in me, were I not loudly to proclaim, there are Parisians, who, understanding the sacred title of friend, are justly entitled to bear it. Their feelings are easily roused, and a tale of woe generally meets an ear of pity; yet, when offended, they are revengeful in the extreme. Not content with punishing the object who has offended them, they will extend their malice towards the several branches of a deserving family. The ladies are graceful and fascinating, nevertheless, in some points vulgar and inelegant; the slaves of pleasure, more perhaps from the effect of education and custom than of choice; but when a French lady (which is frequently the case) possesses some of the more solid feminine virtues, I think she shines superior to an English woman, inasmuch as her natural naviete, tempered by prudence, renders her a lively and agreeable companion; unlike the English, always inclined to view the brighter side of events, her temper is more equal, her several duties are performed with ease and cheerfulness, and, I think I may add, she approaches as near perfection as human nature can hope to attain. Paris may boast several charitable institutions, but poverty and misery are very general. External grandeur is sought by most with avidity. Comfort seems here a secondary consideration with all. To the honour of the nation they are very sober. To the dishonour of the nation they are great gamblers. They, like all other people, have many virtues and many failings; much to be admired, much to be condemned. They are the professed lovers of liberty, and the victims of slavery. Such is my opinion of the French. Their principles I do not generally admire, nor wish to imitate, but their merits, I think, are far more numerous than the English would willingly allow them. L. M. B.

The following communication is inserted that both parties may be placed on an equal footing as far as respects the Magazine.

script to some of his remarks on propulsion, to give at least a hint, that the whole subject matter contained in my Essay, published in the July number, was not only visionary and futile, but wholly borrowed. It is in fact a copy of what he published in a daily paper, and which would never have been replied to, but by the earnest solicitation of my friends, and if my reply was severe, as he supposes it to have been, it was so by necessity;-he called it forth by the unqualified nature of his positions. A subsequent and short communication of bis, through the same public print, has excited feelings on this occasion quite different from what otherwise might have been indulged. I can never "fallen foe"-and should not wound a now make any reply if it was not that yours is a standard work, where the pros and the cons should all appear together. My Essay, though drawn up in haste, was not drawn from hasty deductions-the subject was familiar to me, and I gave it to the public open to fair and candid animadversion. I claimed no originality, other than a new application of known principles. To have received, therefore, an impartial criticism from learned men, would have been pleasing, and no doubt, in some respects, might have been advantageous ;-but I never did, and I never will, attempt to establish any plan of mine by derogating from the merit of others. What Mr. Busby means by saying (in the last communication in the public paper) that "the point had been abandoned and now taken up again in despair," is to me inexplicable-1 must consider it, however, I suppose, as a "ruse de guerre" to draw off attention and make a safe retreat. If Mr. Busby thinks that the communications in the public prints, signed "A friend to merit," came from me, he is mistaken, and the publisher of the paper may satisfy him of that fact.

66

Now, in return, if Mr. Busby wishes his work to be examined with a candour which I court towards mine, I will undertake to point out some supposed imperfections in his arrangement-particularly as regards the action of the syphon, and perhaps may do him some essential ser

vice.

The following is the answer alluded to in the beginning of these remarks, nearly in the words in which it appeared in the To the Editors of the American Monthly Commercial Advertiser." Magazine.

[blocks in formation]

"Messrs. Lewis and Hall,

"In your paper of the 7th inst. your correspondent, Mr. Busby, has made an effort to impress the public mind with the

idea of the fallacy of my system for propelling vessels, by the power of fixed air, as published in the current number of the American Monthly Magazine.

Although this really merits no serious reply, and I have hitherto thought it wholly superfluous to make any, yet I have so far yielded to the advice of my friends, as to endeavour to place Mr. Busby and his authorities in a proper point of view. And till I have time to give occular demonstration, I trust the following will serve to remove doubts imbibed by those who may have but partially considered the subject. The following are the particulars of his first reference: Extract from Dr. Franklin's letter to Mr. Ley Roy, dated Paris, Dec. 22, 1785. "Among the various means of giving motion to a boat, that of M. Bernoulli appears one of the most singular, which was to have fixed in the boat a tube in the form of an L, the upright part to have a funnel kind of opening at top, convenient for filling the tube with water, which descending and passing through the lower horizontal part, and issuing in the middle of the stern, but under the surface of the river, should push the boat forward. There is no doubt that the force of the descending water would have a considerable effect, greater in proportion to the height from which it descended, but then it is to be considered that every bucket-full pumped or dipped up into the boat, from its side or through its bottom, must have its vis inertia overcome so as to receive the motion of the boat, before it can come to give motion by its descent -To remedy this I would propose the addition of another side L pipe, and that they shall stand back to back in the boat, the forward one being worked as a pump, and sucking in the water at the head of the boat, would draw it forward, while pushed in the same direction by the force of the stern.' And after all it should be calculated whether the labour of pumping would be less than that of rowing. Perhaps this labour of raising water might be spared, and the whole force of a man applied to the moving of a boat by the use of air instead of water; suppose the boat constructed on this form-a tube, round or square, of two feet diameter, in which a piston may be moved up and down, the piston to have valves in it opening inward to admit air when the piston rises, and shutting when it is forced down, and let the air pass out, which, striking forcibly against the water abaft, must push the boat forward.'" VOL. II-No. v.

[ocr errors]

47

Extract from the specification of James Linaker, Master Millwright of the Dock-yard at Portsmouth.

"First method, consists in applying a bucket similar to the bucket of a lifting pump, to be moved by any sufficient power backwards and forwards in a tube attached to said vessel, in a direction parallel or nearly so to the direction of the intended motion of said vessel, which is to be moved forward upon the water by the effect of this bucket drawing in the water at one end of this tube and delivering it out at the other in a direction of the motion of the said vessel; for this purpose the bucket and tube must be provided with valves, after the manner of a lifting pump. Second method consists of an improvement upon a method where a forcing pump has been used for the same purpose, but in lieu of admitting or drawing in the water by the piston of the forcing pump perpendicular to the direction of the intended motion of the vessel, I admit or draw in the water by the said piston of the forcing pump in a direction parallel or nearly so, but contrary to the direction of the intended motion of the vessel, through a tube attached thereto, by this meaus combining the effect of admitting or drawing the water in, along with the effect of forcing the water out in the best direction for giving the intended motion or impulse to the vessel."

It is now necessary to show the difference between these theories and mine. It will be observed, that the means described by Doctor Franklin, as employed by Mr. Bernoulli, to give motion to his boat, are very simple, merely by the weight of the water which was poured into the top of the funnel part of a tube; and by its pressure on the water, under the surface of the stern, to push the boat forward. This idea of Mr. Bernoulli, is good as far as it goes, but does not resemble either of the methods exhibited in my Essay. Dr. Franklin's suggested improvements on Mr. Bernoulli's plan, are intended to facilitate its operation and increase its effects; and his proposition of substituting air for water, seems intended to save the labour of raising the water-but, in this respect, he appears not to have given the subject all that attention he was accustomed to bestow on philosophical researches. The doctor's idea of bringing the water in at the bows of the boat, to supply the pump, certainly exhibits the "negative" principle of applying power, and shows, though in an imperfect manner, one of the three operations of my plan. His application of

the water thus obtained, is by the operation of its gravity below the surface under the stern of the vesscl; 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 conception 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 Phoenicians, the Egyptians, the Tyrians, the Carthaginians, and the Romans, had their biremes and triremes, &c. all moving 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 moderns 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 attainable. 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."

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." 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 method 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

[ocr errors]

swell this article for an ordinary commu-
nication-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 Re-
pertory of Arts, of 1815, for a description
of an
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 in
genious 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. Fees' Cy-
clopedia, under the article Steam Engine
that this gentleman has obtained a pa-
tent 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 pre-
sume it is not of great importance.
Hence it clearly appears, that Mr. Mur-
ray's air pump was only intended as an
improved auxiliary to the steam engine,
and not an "Air Engine" as "a pri-
mum mobile," which Mr. Busby appears
to consider it.

[ocr errors]

Mr. Busby further states, that "many expensive experiments (some of which he witnessed) have been made in England under the superintendence of the first Inathematicians 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 acrostation, 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 knowledge 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. Bushy'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 axicm in mechanics, that whatever was gained by its complication, one-third of it was lost by mere friction. Hence my present wheel having only sir paddles instead of eight, the usual cumber, 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, operat ing upon the combined princi; les 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 advan tage he has ascribed to his own in-perfect 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 undiminished,

[ocr errors]
« AnteriorContinuar »