and cost -- and 42, (which were located 2 miles above the single guard gate, and enters at the foot of lock The pass at the Point of Rocks, held in dismouth of Opequon,) to 2 miles below the mouth No. 5. Length of the dam, 1750 feet, height 4 pute between the two companies, was $11,153 of that river. (This transfer reduced the slack feet. Cost The feeder is a part of feet long, or 2 miles. The distance from water navigation, between guard lock No. 3 the old canal around the Little Falls, constructed Harper's Ferry to Cumberland, according to and lift lock No. 41, from 7 to 3 miles, and in-previous to 1800. Geddes and Roberts' report, is 127 miles, and creased the expense $100,000. There is also No. 2. The Seneca feeder supplies 17 miles, the amount of all the narrow passes where the a lift lock in addition to the above constructed, although at the foot of lock No. 18, at the Great works would come in collision would amount connecting with the Potomac opposite the Falls, an additional supply is received from the in all to 45 miles. junction of the Shenandoah with the Potomac Potomac, through a small arch under the tow- The reports of the united engineers, who at Harper's Ferry, 637 yards above lock No 32. ing path. The dam across the Potomac for this have been at various times invited by the comIt has 10 feet lift, and is, in other respects, si-feeder is feet high, and 25,000 feet in length, pany to inspect the different portions of the milar to the other locks. The water is admitted into the work, are all declaratory of the perfect and subCulverts. Below the Point of Rocks there canal through guard lock No. 1. The dam is stantial manner in which the work has been are, inclusive of roadways, 59 culverts, of which of stone and arched. constructed throughout. These reports, have the total cost was $110,000. Three of these No. 3. The canal for the next 40 miles de-been called for by Congress, and, on being culverts are of 12 feet span each, 2 of 16 feet pends almost entirely for water on the supply submitted, have been ordered to be printed. span each, (one over the Tuscarora, 2 miles it receives from the Potomac at the head of They contain a great deal of information relaabove the Monocacy aqueduct, and the other 1 Harper's Ferry Falls. The dam constructed tive to this grand work, and are worthy of pemile below the Point of Rocks,) and 1 of 2 by the Government for the use of the United rusal. This spring, notwithstanding the many arches of 16 feet span each over the Little Mo- States armory at Harper's Ferry answers all delays and difficulties of the most arduous and nocacy river: the total number of perches of necessary purposes here, and no more water is imposing nature the company have had to conmasonry in these 59 culverts amounts to drawn off than was formerly used by the old tend with, will see the canal opened some discosting $51,872-32 culverts, nearest Point of canal, which has been closed since the opening tance above Williamsport, a distance of 102 Rocks, 11,357, $50,000. Between the Point of of the main canal. (A small feeder from the miles of canal, and 14 slack water navigation, Rocks and Harper's Ferry the number of cul- Tuscarora, which enters the canal 17 miles be- fully complying with the charter, which required verts is 19, containing in all 6,839 perches of ma-low the head of Harper's Ferry Falls, also as upwards of 100 miles to be completed within sonry, and the total span of which was 158 feet. sists towards supplying this section.) The 5 years from its commencement, or rather from There are, also, above Harper's Ferry, 41 cul- water from the Harper's Ferry feeder is admit October, 1828. Some report I have just got verts, the estimated price of which was $44,300. ted through guard lock No. 2, situated near lift hold of, says the entire cost of this construction The culverts below Harper's Ferry are gene-lock No. 35. This dam is feet high, and was $3,650,000, of which $450,000 was exrally 110 feet long; while above, owing to the feet long. Cost of company's works here pended from Little Falls down. contraction in the width of the canal, they do No. 4 supplies 23 miles of canal. across the Potomac is near and Aqueducts.-No. 1. Seneca aqueduct, built of is 20 feet high, and 810 feet long, and 60 feet red sand stone from the immediate neighborbase. The water is admitted into the canal hood, is 114 feet long between the abutments, through guard lock No. 3, which is 1 mile 320 which, with the 2 piers, rest on a solid founda-yards above the dam. Cost of dam, lock, and tion. There are 3 arches of 33 feet each. Cost other works connected with the feeder, $22,784. No. 5 feeds 19 miles of canal, and is situated miles above Williamsport. The dam across and is feet high, 706 feet long, and 20 feet base. The water is admitted through guard lock No. 4, 320 yards above the dam. not exceed 100 feet. Cost The dam Some facts I have not here been able to find Aqueduct No. 2. Monocacy aqueduct, built of a white granite stone, (obtained within 3 miles of the Potomac is at the site of the aqueduct,) is 438 feet in length be-20 tween the abutments, and is 516 feet from end to end of the wing walls which project from them. There are 7 arches of 54 feet span each, and 9| feet rise, (segments of circles,) the radius of intradoes of which is 45 feet. It contains 9,788 perches of masonry, (exclusive of the rough walls in which the cut masonry of the wings terminates.) Cost, $125,000. out, but which I hope you will be able to obtain, I can add that the prospects of the canal are truly encouraging. Having command of an extensive coal region, and passing through a highly cultivated valley, where there are also numerous grist and other mills, and abundant mineral resources besides the coal, they can never be at a loss for means of rendering the canal profitable. They cannot experience much competition, either from the Baltimore and Ohio Railroad, on account of the heavy weight of the produce to be conveyed, and cheapness of conveyance on the canal. The Washington city branch of the Chesapeake and Ohio canal extends from the Rock Creek Basin on the western borders of the city to the mouth of Tiber Creek, following the bend of the river COSTS.-The following work, done between Potomac, (being constructed along the bank of the Point of Rocks and the Georgetown Basin: that river, and in some few places encroaching -Common excavation, 1,893,665 cubic yards; on the river itself,) a distance of 1 mile and Aqueduct No. 3 crosses the Catoclin, a tri-Hard pan do., 439,071 do.; Quarry rock do., 373 yards. A tide lock at the eastern terminabutary to the Potomac ; it has 3 arches, a semi-75,472 do.; Rock blasted, 398,524 do.; Em-tion brings it to the level of the Potomac. The circular, of 20 feet span each, and the third a bankment, 1,533,850 do.; Puddling, 96,092 do. ;||cost of this branch was $25,978.47. semi-ellipse of 40 feet span and 10 feet rise, Walling, 231,064 cubic perches. Costing Very little has yet been done on the Alexansupported on piers, 6 feet wide by 33 feet long, $1,032,161; for grubbing, $12,892; extras, dria branch of the canal. Congress has made while the parts under water (7 feet in depth,) are $40,800. an appropriation of $60,000, I believe, for the 8 by 35, and founded on solid rock. Total cost, lock, at Georgetown, $78,943; Locks, $232,642; across the Potomac, for the transfer of the Extra on this section:-Pier, basin, and tide construction of an aqueduct at Georgetown, $33,500. Aqueduct No. 4 is over the Antietam, a Lockhouses, $16,315; Bridges, $32,925; Aque-canal to the Virginia shore. The length of branch of the Potomac, entering 3 miles above ducts, $23,444; Culverts, $51,872; Waste weirs, this branch is 7 miles and 416 yards, and the the Government dam above Harper's Ferry.$8,619; Dams, $30,491; Guard locks and feed-estimated cost $372,204.55. The aqueduct has The abutments are 9 feet thick, and 108 feeters, $15,404; Improvements, $22002. apart. It has 3 semi-elliptical arches, 2 of The masonry on the dams, locks, aqueducts, 28 feet span, and the 3d of 40 feet span, with a pay for engineers, officers of the company, &c. rise of 10 feet each. The foundations of the are not included in the above. items given piers and abutments are on solid rock. Greater separate. portions of them are of cut stone masonry and expensively built. Lime stone from the neighborhood used. The towing path parapet is 7 feet thick at bottom and 6 at top. The berm parapet is 5 feet thick at bottom, and 4 at top Width of track is 20 feet at bottom and 22 at top. Cost, $22,850. Aqueduct No. 5 is over the Conococheague, which enters the Potomac at Williamsport. It has 8 arches of 60 feet span each; two piers and two abutments. The piers are 12 feet thick at the base. The arches are 32 feet widel and 15 feet rise. been contracted for some time since, and is now in progress of construction under the superintendence of Capt. Turnbull, U. S. topographical engineer. It is 1714 feet long; the canal way is to be 16 feet wide at bottom, 18 Work done and to be done from the Point of feet at top, and 5 feet deep, and thence, to Four Rocks to Williamsport-all under contract, and Mile run, the size of the canal is to be 32 feet a great portion finished:-Common excavation, wide at bottom, 50 feet at top, and 6 feet deep. 2,733,905 cubic yards; Rock do., 433,752 do. At the embankment, at Four Mile run, it is to be Slate do., 8,140 do; Embankment, 1,350,149 18 feet wide at bottom, 36 feet at surface, and do.; Puddling, 37,617 do.; Walling Stone, 6 feet deep. Thence to Alexandria it is to be 181,029 cubic perches. Actual and estimated enlarged to the established dimensions of the cost of the above, $936,735.74; for grubbing, Chesapeake and Ohio Canal. $9,653; extras, $8,564.13. Total, $954,952.87, besides the masonry on locks, aqueducts, culverts, bridges, &c. &c. I have not been able to obtain a full aggregate amount of the expenditures of the compaTow-path parapet, 7 feet thick at bottom, 6y, nor an actual statement of the entire cost of at top; berm parapet, 5 feet thick at bottom, 41 at top. The walls are raised 7 feet above the bottom of the canal. the canal. It has had to meet enormous law expenses on account of its difficulties with the Baltimore and Ohio Railroad Company; besides being subjected to very large losses in the delay occasioned by the injunction of the Chancellor of Maryland in the above case. The Feeders.—No. 1. The Little Falls feeder sup-right of passage, too, over the various lands of plies 43 miles of canal. An arched stone dam private individuals has cost immense sums. is thrown across the Potomac, and the admis Estimated cost, $40,260. Not quite finished in December last. sion of water into the canal is regulated by a' * We have not been able to fill the blanks.-ED. A. RJ. H. N. C. P. S.-We have received the communication which will be given in our next. promised, giving the rates of toll on the canal, The Undulating Railway-Final Reply of Mr. Badnall to Mr. Cheverton. [From the London Mechanics' Magazine.] Sir, Mr. Che verton's dreadful inflictionHIS ROD-hath, at last, fallen upon me, without his own character, or the good taste of your readers being, in the slightest degree, "ill-consulted"-without the most distant apparent inclination to render your pages the medium of a personal quarrel between himself and me! HE 66 will not descend to imitate my dull, vitupera- As no unnecessary time will now be lost in recently, when he did me the honor to spend tive style! He would shudder to characterise trying, by ample experiment, on some line or part of the day with me in Liverpool. In a an opponent as a coarse practitioner from the other, the merits of the undulating question, word, the only individuals whom I can call to abattoir !"-" a mere hacker of flesh and I would propose, to your readers in general, mind as having expressed a decided opinion in bones!" HE is a man of more gentlemanlike that all further controversy should rest until the my presence, when in London, adverse to the bearing than to fume out false accusations! experiment be made. Practice can alone de- undulating railway, were Mr. Saxton and a No, Sir, HE stands upon too lofty an eminence! termine whether I or my opponents have been friend of his, whom I begin to think was Mr. His philosophic and refined understanding right or wrong in our anticipations, and whe- Cheverton; and as to any acquaintance of could not possibly stoop to mere personal abuse, ther Mr. Cheverton's arguments or mine will mine then present being afraid of their “bador controversial subterfuge! No, HE is the be creditably substantiated. The note which gering," I rather think Mr. Cheverton has imvery prototype of wisdom-an immortal em-you have attached to my last communication bibed an erroneous impression. If it were neblem of refinement !-a breathing picture of leads me to hope that you may concur in my cessary, I could publish, in this letter, a list of urbanity and peace !-gentle as a lamb-sweet present opinion;* and if so, while Mr. Che- persons who are advocates of the undulating as honey-mild as new milk-"parfaite amour" verton may try at his leisure any further expe- railway, amply sufficient to out-balance the in toto! HE is not the cur who, when he meets riments he may please at the National Gallery strongest testimony which Mr. Cheverton and with an unflinching antagonist, flies growling of Practical Science, I will direct my attention his friends can advance against it, but the and barking to his kennel! He is not the tame- to the means of elucidating the problem in a best testimony is practice, and upon that I throw hearted pugilist who swears that a blow is far more satisfactory way. If, on a trial being the merits of the case. false because he cannot parry it!-nor is HE made, I find myself in error, I will frankly con- Lastly, Mr. Cheverton offers some important slippery as the eel, which, by its twistings, and fess my incompetency to argue this subject, practical objections, which I confess to be more its twinings, and its slime, evades the grasp of and my folly at having so warmly and so worthy of notice than any points which he has its pursuer, and buries itself in its native mud! boldly espoused it-if otherwise, I trust there hitherto advanced. But, serious as they ap No, Sir, Mr. Cheverton is a being of far different are many of your readers who will give me pear, they will not, on consideration, be found stamp!—his mental qualifications-his scienti- credit for some patience, and for some in- of any real weight. In the first place, we have fic reputation-his temper-his writings-his tellectual capabilities beyond the canaille sphere to determine what is a safe velocity—that being sentiments-will all bear the test of the most in which Mr. Cheverton has been so anxious to determined, how can can it be attained on a rigid scrutiny! His theories will all be estab- place me. level railway with heavy loads? Unless gralished by practical results! The halo round The test shall not be less difficult than I origi-vity be employed at starting, as an auxiliary HIS head will brighten as each opinion becomes nally proposed. Whether the experimental rai!- force, a much more powerful engine would be confirmed by experiment! In a word, HIS way be 6, 8 or 10 miles in length, I maintain that requisite to move a heavy load from a state of letters on "the undulating railway," while they any locomotive engine will traverse an undula- rest, than to continue it at a given maximum will immortalize the fame of the Mechanics' ting line, with a load which is its maximum load velocity; and if gravity be employed at starting, Magazine, will become never dying monuments on a level, in half the time which it will occupy the engine and load must ascend again to a of sterling talent and correct observation, from in traversing the same distance with the same like summit, in order to maintain the starting the hour when that trial takes place, which a load on a dead level railway, and without greater advantage; and if so, what is this but an unduDalton* has been indiscreet enough to recom- waste or consumption of fuel. And I, more-lating railway? Does Mr. Cheverton imagine mend! Till that hour arrives, I almost feel over, say, that any locomotive engine will tra- that a perfect cycloid, or a perfect arc, alone inclined to "leave him alone in his glory," in verse an undulating line at a great velocity with constitute my idea of an undulation? Far from order that I might, with double effect, magni-a load which that same engine cannot move it-he may descend a hill, run four miles on a fy his transcendent name, and prostrate myself upon a level line. level, and ascend to an equal elevation; and by before his living monument of wisdom! But Whenever this trial may take place, your doing this would realize a system of undulation -I cannot resist the inclination which his let-readers shall have ample notice of it; and if which might, probably, be adopted with advanter has excited, to pay him some passing hom-you, Sir, will undertake the office of unipire, Itage in some cases; for, with heavy loads, a ve. age; for neither the " war-whoop of the Mo-shall cheerfully abide by your decision. locity might be generated by the first descent hawk," nor the "inspiring blast of the clarion," In the meantime, it would be mere repetition,||which could not, with the same engine, be gene. shall be compared to the sounding of his brass, and an unnecessary prolongation of our argu-rated on a dead level; and this being maintainor the tinkling of his cymbals ! ments, were I to reply at length to the more ed on the level, would enable the load to ascend Yet how shall I, to whom "nature has been solid parts of Mr. Cheverton's last letter. One to a like elevation. But supposing the undulaso niggardly," sufficiently extol the praise of or two points, however, I cannot help touching tions to be a series of regular segments of cir. one who, declining to quarry all ignoble game, upon. First, as to locomotive duty," which cles, wherein consists the difficulty of sustainis able to defend himself against a weapon ca. he so frequently harps upon. All my arguing an average velocity of 20 or 30 miles per pable of dividing "soul from body," the very ments, of late, have been almost confined to hour, without an increase of speed? Is it ne"marrow from the bones?" the practical consideration of locomotive duty.cessary to work the engine down every descent! Immortal champion! inspired philosopher! I do say that by employing gravity as an auxi- One of the leading advantages which I anticitender and kind-hearted victor! may this hum-liary force, we save locomotive power. What pate is the great saving of that steam expendible panegyric be a memento of my deference to Mr. Cheverton exclaims, can you take advan-ture which is now necessarily incurred in thy fame, as long as the Mechanics' Magazine tage of gravity without being obliged to repay maintaining high velocities on a level. Again, may survive the wreck of time—and may that what you borrow? Yes, is my reply-and yet it will require very powerful engines to attain be for ages! no perpetual motion, Mr. Cheverton! How high velocities, with heavy loads, on level railHaving thus, Mr. Editor, in sincere good hu- Mr. Cheverton would ask. My answer is sim.ways: whereas, such powerful engines will mor, squared one part of my account with Mr. ply this, and whether it be true or false, experi.not be so necessary on undulating_railways, Cheverton, I beg to acknowledge, like him, the ence will prove-velocity is gained by taking and for the reasons previously stated. gratification which I feel at the prospect of this advantage of gravity. Friction on railways is, I now, Sir, unless again attacked by Mr. too lengthened controversy being terminated. in my humble opinion, not as the spaces, but as Cheverton, close with pleasure this twelveThe venom which he thought it prudent, in the the times or velocities. If this be true-and if month's warfare, anxiously awaiting the result first instance, to cast on me, I good-humoredly a greater velocity be attainable on an undula- of practical trials; and sincerely hoping, alendeavored to throw back; but his last effusion ting than on a level railway, there is, (exclusive though a few waspish observations have occawas of so different a nature-so characteristic of of any difference in friction arising from the sionally intermingled with a subject to which a noble and unoffending disposition, that I have particular inclination of the plane,) less friction they should have been altogether foreign, that met, as it deserved, with an unbounded expres-on an undulating than on a level railway. Lo- some information and benefit may have been sion of veneration. As you have admitted, incomotive steam power is therefore saved. derived from the discussion. your valuable columns, his unmeasured decla- The next point I wish to allude to, is Mr. Chemations, I trust that equal justice may be done verton's observations about a lecture given to to me; and that you will, by publishing this re- me, or some of my acquaintances, by Professor ply, permit me the opportunity of proving that||*******, in the National Gallery. Does he P. S.-S. Y. and I have, in one respect, mishe who cannot, by fair and manly argument, mean Professor Ritchie ?-if so, I was not pre-understood each other. He is certainly right defeat a literary or scientific opponent, stands sent. That gentleman and Mr. Locke had, in believing that the pressure upon an inclined little chance of doing so by an opposite course know, a conversation together; but the only plane, (alluding to the force necessary to draw time that I have had an opportunity of convers-a body up,) is as the base to the length: thereSuch was my object in noticing Mr. Chever-ing with Professor Ritchie on the subject, was fore, at an angle of 45°, my statement appeared ton's extraordinary letter (vol. xx. p. 73). Had it been otherwise, my silence should have claims of Mr. Whitehead and Mr. McKinnon, to whose papers, resolution of the forces-that at an angle of 45° * We do perfectly; but it must be with reservation to the erroneous; but, taking into consideration the shown my contempt for the vulgar sneers and in opposition to the undulating system, (now many months in the length of the base is equal to the perpendi false accusations with which that document hand, we stand pledged to give insertion. We shall be glad to abounded. But it is passed, and I congratulate ED. M. M. have their assent to the proposed postponement in the text.cular elevation-and that taking the length of Mr. Cheverton on the victorious result of his the plane as the entire force of gravity, it forms † It will occur to your readers that I have frequently stated as the diagonal to two equal sides of a square; the attack. my opinion, that an engine would convey, on an undulating line, at least twice the load which the same engine could move oblique forces are therefore equal—that is, at an the test which is above proposed will, I am sure, be deemed body down a plane, or retards its ascent, is exon a level, at the same velocity. Such is my opinion now; but angle of 45°, the force of gravity which urges a sufficient to decide the question at issue, and it will be found to accord with the terms of my original challenge. lactly equal to the force of pressure on the of conduct. Alluding to the trial of the undulating railway, which Drs. Dalton and Lardner have recommended to be instituted on the London aad Birmingham line. I am, Sir, with great respect, your very obe- plane. For instance, if L be the length, B the base, and E the elevation, at an angle of 45° E is equal to B; and although the pressure on the plane is XL, yet the tendency to descend is L B L E XL; the one force, therefore, is equal to the other. I close my discussion with S. Y. with every feeling of respect. similar to that attributed to Mr. Burden, or steam raft, and further particulars rewith this difference, that the bows of my specting that, and four others which I confloaters were to be considerably more eleva-structed subsequently, having varied the dited than those of Mr. Burden's raft. The mensions of the floaters, and the substance following year, being in Paris, and foresee-of which they were composed, I will furnish ing the probability of being detained there them with pleasure. I remain, sir, your for a considerable time, I set about construct- most obedient servant, ing my raft. I took two deal planks, of 30 ALFRED CANNING. feet long each, 12 inches wide by 6 inches Crown Coffee-House, Holborn, March 18, 1834.! thick, and having fashioned each like a ca[We shall be glad to hear again from Mr. MACHINE FOR EXCAVATING EARTH.-Mr. G. noe, I placed them on edge, parallel with Canning on the subject, with drawings, not V. Palmer, of Worcester, has been ten years each other, about 5 feet asunder, and con-only of his original model, but of his more and upwards engaged in constructing an extra- nected them together at about 3 feet from the matured plans of construction, and all illusordinary engine to excavate earth, &c. for surface of the water, by a decking resting upon trative particulars.-ED.] which he has taken out a patent. This engine 4 stanchions, of about 7 feet long, which rose works by steam, and is particularly adapted for [See page 384.] NOTE. Since the article in our present cutting canals, levelling hills for railways, and nearly 4 feet above the deck, and served to number, on the great American steam-raft removing large masses of earth. The engine support a handrail, as well as to maintain in was in type, we have received a letter from an cuts, at a single blow, six feet in width and square the whole frame-work, by diagonal esteemed correspondent, from which the folthree feet in depth-delivering on either side, ropes, which passed through holes in the "The velocity attained or into carts, one ton and upwards per minute: tops of the stanchions and holes in the deck.lowing is an extract: it also cuts and sifts gravel in the same propor- I tried this little model raft, both with oars, a7 inches water. They expect, with another was in still water. The vessel draws only tion for road-making. We understand it is of sail, and paddle wheels (worked by the feet), that is completing, to perform twenty-seven great simplicity of construction, and the weight of the engine does not exceed three tons.and found that I was not deceived in my ex-miles an hour." [Manchester Courier.] We copy the following from the forthcoming number of the Mechanics' Magazine: pectations of its speed, which was astonishing. I had a rudder of sheet iron, in the shape of a fish tail, adapted to each side- Account of Steam Engines and their Inventors. piece or floater, which were connected to[Compiled from authentic sources.] BURDEN'S BOAT.-This "wonder of the gether and acted upon by diagonal cords The elegant toys of Hero, the beautiful age" made its second trial on Wednesday and a cross-bar. Prince Joseph de Chimay, experiments of Porta and Decaus, the modhis sons, and several other persons of high ifications of the Greek machine by the unlast, June 10th. We have all along exrank, witnessed my trials. Finding it suc- known Italian, the practical merit of the pressed our conviction that Mr. Burden has ceed so well, and possess so many advan-" water-commanding engine," the ingenious stated nothing that he will not accomplish; tages over every description of boat, as it ideas of Hautefeuille, and their masterly we think so still, and so does every practical was not liable to sink or upset, &c. &c. I extension and developement by Papin, conman we have conversed with on the sub. determined to construct a much larger raft, tain all the rudiments required for a perfect and propel it by steam; but owing to the machine, waiting only to be touched by the ject. But we do hope, that Mr. B. will not jealous spirit of the boat owners on the wand of some mechanical magician, to form allow his anxiety to realize his promises in- Seine, particularly Prosper-Colin, and Dag. a structure of surpassing ingenuity and terfere with his judgment, or in any way net, who had great influence with the Pre- semi-omnipotent power. prevent his doing that which he has pro- fect, I was not able to procure a permission The total neglect with which these indito place it upon the river. Being immedi-vidual schemes were regarded is not the mised to accomplish, WELL. We insert the ately afterwards obliged to absent myself least extraordinary circumstance in the hisannexed engraving as a correct represent- from Paris upon urgent business, I left my tory of the steam engine, and, above all, the ation of it, and take this opportunity of in-model raft afloat, in the care of a waterman, oblivion which followed that of Lord Wortroducing to the notice of our readers a con- who lived in his barge upon the Seine, at cester, whose unconquerable perseverance, densed account of steam engines and their the foot of the Pont Royal, directly under at the lowest ebb of his fortune, found means inventors, compiled from authentic sources. the windows of the royal palace of the Tui- to carry his splendid ideas into practice. It In a few days she will make her first trip to leries, one of the greatest thoroughfares in appears improbable, but that his mechanism, Troy.-[ED. MECH. MAG.] Paris, where it remained for five months. whatever it was, was forced upon the attenUpon my return, the waterman (Laporte) in- tion of many parties connected with the formed me that several foreigners, particu- draining of mines; and from the character The Great American Steam-Raft of English larly Americans, had made repeated inquiries of the Marquess, it is equally remote from Origin. By ALFRED CANNING. [From respecting the nature of the raft, and that belief that he would fetter the introduction the London Mechanics' Magazine.] two American gentlemen had made drawings of his invention into general use, by a high SIR,-Having noticed in your Maga- of the raft; and had observed, "that rafts con- price asked for his permission to use it. The zine for Saturday, 22d ult., an account of a structed upon the same principle would suit utter novelty of the nature and power of the raft propelled by steam, considered to be the well the lake navigation in the United agent, an ignorant and absurd idea of its invention of a Mr. Burden, in America, I States." danger, and the total want, probably, of any think it due to myself to state, that in 1817 Should you, Sir, or any of your readers, mechanical means, except that of mere I conceived the idea of constructing a raft feel desirous of seeing a sketch of my sailllstrength of parts to guard against accidents * * * a may have been the real causes of its neglect, eye-witnesses, and all people seemed to like In the pamphlet in which Savery appeals and exclusion from practice. it, the public newspapers speaking very large-from their judgment to that of the public, he Thirty years after Lord Worcester's death, ly of it, yet all to no purpose." (p. 18.) The pays less attention to the reasons urged a brilliant ray of improvement suddenly inexorable lords of the admiralty were "so against its novelty, as well as practicability, bursts into the history of the steam-engine, much altered that, from commending the than they were fairly entitled to receive.* from the consummation of the labors of a thing, they would not hear one word in its de-In his resentment he says, that "not a tittle Captain Thomas Savery, who had been si- fence." (p. 15.) Savery, notwithstanding, will he disclose of two other inventions of lently employed in combining a mechanism," being informed by Sir Martin Beckman, his until he has justice done him on account in which elastic vapor was the motive power. the greatest engineer in the Christian world, of his rowing engine." The first of these Of the history of this distinguished man that the thing was good, got a noble lord to was "a gin of fourteen inches square, portlittle is known. show a draft of it to the king a second time, able by one man, and by which one man He is first presented to our observation as who ordered me," says Savery, "again to may lift the largest cannon into her car. an author of a scheme for rowing ships in a the admiralty, who never ordered me in be- riage." The second contrivance was calm, for which, after obtaining a patent, he fore them, but, after waiting two or three method whereby he could fight any ship, in vain endeavored to procure the patronage days, the doorkeeper told me that my busi- using charge and discharge as often as six of Government. "The trial of my scheme ness lay before the navy. Upon which, next do now, and to as much purpose, without was unjustly thwarted by one man's humor," day, I desired a friend of mine to go with any manner of incommodation, more than said Savery. "A regard to my duty, as me to the navy office, that he, being a man by the common way, so that one half of the well as place, will not permit me to give a of extraordinary judgment, and no less re- men need not be exposed that now are, and biassed opinion," said the umpire. "But Iputation, might be an evidence to what dis-the rest may be kept as a reserve for board. have tried it," replied the projector, "on a course might happen; but coming to the ing; the benefit of this I leave to the inge. small scale, and it answered completely." navy office, we found the board was rose.nious sailor."† "So have we," said the servants of Govern- However, in the hall I found Mr. DThe enthusiasm of the projector was softment, "and in our trial it failed completely." I asked him whether any thing was come ened in Captain Savery by the experience Savery afterwards remarked: "I was ne- before the board concerning my business. of a practical mechanic; and he early ap cessitated to write my book; for after I had No,' said he, 'not since the objections sent pears to have acquired that personal consideracked my brains to find out that which a to the lords of the admiralty;' on which he ration which usually follows a man of ge. great many have spent several years in vain could not but fall into an argument. I asked nius and enterprize, when his habits are in the pursuit of, when I had brought it to a him some questions in relation to his objec- those of a man of business. draught on paper, and found it approved by tions, and in a very little time we had a great At the first announcement of his machine those commonly reputed ingenious, and re- puther about superambient air and water. for raising water, he had so matured his ideas, ceiving applause, with promises of great re. I found that my sailor ran himself fast and was so well versed in the nature and ward from court, if the thing would answer aground, as men commonly do when out of power of the motive agent, that his master. the end for which I proposed it; after I had, their knowledge; this, indeed, made me pity ly combination has left but minor objects for with great charge and several experiments, him again, although I was willing to come improvement to succeeding engineers. His brought it to do beyond what I ever pro- at the plain truth of the matter, and asked mode also of introducing his invention to the mised or expected myself, at last one man's him whether or no he could not bring one notice of the public was totally different humor, and more than a humor, totally ob- hundred and fifty men to work at this engine, from that which had been followed by for. structed the use of my engine, to my no he answered yes; then, said I, will they not mer projectors. They enveloped every thing small loss; but it is the nature of some peo- have as much power to give a ship motion as in mystery, and endeavored to attract atten. ple to decry all inventions, how serviceable one hundred and fifty men would have on tion by exaggerated statements of power soever to the public, that are not the product shore, at a hawser fastened to the ship; this or economy. His first step was to explain of their own brains." he likewise answered in the affirmative. to every one the principles, as well as construction, of his apparatus: he showed why 6 He gave an account of it to secretary Then, said I, it will do more than oars, or Trenchard. "A few days after, the secre- any thing but a gale of wind, and fully antary told me that the king had seen my pro-swer my proposals. Well, said he, with a posals, and that I need not fear, for that the smile, and putting off his hat as taking leave, king had promised me a very considerable WE are all submission to the lords of the reward, and that I must go to the lords of admiralty.' the admiralty to put it in practice; but that "Not long after, a friend of mine met a first I must make a model of it in a wherry, commissioner of the navy, and my friend, which I did, and found it to answer my ex-being perfectly acquainted with my contripectations. Then I showed a draft of it to vance, asked the commissioner why it was the lords of the admiralty, who all seemed not put in use by them? The gentleman to like it, and one amongst them was pleased offered several objections, which were, by to say that it was the best proposal of the sound reason, fully answered by my friend, kind he ever saw; so I was referred from that he had only this hole to creep out at. them to the commissioners of the navy, who Sir,' said he, ‘have we not a parcel of inall seemed to like it, but told me that the genious gentlemen at the board?' model must be surveyed by Mr. D, the said my friend, I hope so, or five hundred surveyor of the navy, whose opinion I asked; pounds per annum is paid them to a fine but he was very reserved, and said, that a purpose.' Is not Mr. D—,' said the wherry was too small a thing to show it in, commissioner, one of them, and an inge there being no working at a capstan in a nious man?' I hope so,' continued my wherry; but he told me it was a thing of friend. "Then,' said he, what have intermoment, and required some time to consider loping people, that have no concern with us, on; for should I,' said he, give a rash judg-to pretend to contrive or invent any thing for ment against it, I should injure you; or for us?'" 6 'Yes,' In Navigation Improved, or the art of rowing ships of all rates, in calms, with a more easy, swift, and steady motion than oars can, by Tho. Savery, gent. London, 1698. seilles, at the expense of the King of France, to navigate The results of these trials were very satisfactory, and a vessel by revolving paddles, or wheels, instead of oars. strongly directed the attention of philosophers, as well as mechanics, to the practicability of this application of water-wheels. [Machines Approuvees, tome i. p. 173. 1693 a M. Duquet made several experiments at Mar + Sir Isaac Newton, in a report (dated Leicesterfield, "Mr. January 27, 1718,) which he made to the government, on Savery complained of one of his inventions being ne glected, from its resembling a mechanism with which he it, the charge of putting it in practice must Savery, whose bluntness, probably, was prove a loss to the king, and endanger my no recommendation to his application, has employ.'" several flings at the "boards," and his state. After four months' consideration, Dummer ment is wound up by a dexterous one at the gave his opinion against Savery. It was contents of courtly Dummer's wig. "Whoneither a new nor a practicable invention, ever is angry with truth for appearing in al part of mathematics, his genius or inclination being that being similar to one used at Chatham, in mean language, may as well be angry with 22 years last past, confining himself to a retired sort of way for machines and inventions, wherein he spent about 1682, which was abandoned, and he designa- a wise and honest inan for his plain habit; life, within his little laboratory; and of late he fixed his ted, though rather disingenuously, the cap. for, indeed, it is as common for lies and non-ment of navigation, which he could not bring forth to ef projects upon a particular invention, towards the improvestan and its trundle as "clock-work;" and sense to be disguised by a jingle of words, fect in the island, for want of able workmen; but he came although Savery "exhibited his wherry on as a blockhead to be hid by abundance of to London on purpose, and he hath actually begun, and the Thames, and thousands of people were "peruke."-[Navigation Improved, p. 33.] hopes, with the blessing of God, to bring it to some perfection."-[Memorial, p. 4.] it was a cheaper power than that of horses or men; and he invited practical men to judge for themselves of the value of his assertions and statements, by an inspection of the machine itself in operation. The influence of the court was at this period considered to be essential to the success of any speculation which required the aid of a monopoly. The profits might be diminished or overthrown by the obstacles which avarice and intrigue could then interpose in that quarter to its further progress; and from this circumstance, considerable importance was attached to having the countenance of those in power to any project in which the pecuniary risk required to be ex tensive; and Captain Savery might be said be left a vacuum, and the atmosphere seek-although a nearer approach to the present to be conforming to an almost common prac-ing to occupy that space will force the plug form of the steamboat, can neither be consitice, when he exhibited a working model or C down to the line A; here the movement dered as the first suggestion for moving his fire engine before King William, at of the plug C was solely caused by the at-wheels by steam, nor any improvement on Hampton court. That monarch, who him-mosphere exerting itself to regain the posi- the idea which emanated from another-nor self had a mechanical turn, was so pleased tion whence it had been expelled by the even any specimen of mechanical skill, for with its ingenious construction and effective force of the steam through D, and this ef- it is awkward, clumsy, and inartificial; but, action, that he took a warm interest in its fect is performed by the consequent power as his claims have been put forth to a higher success, and permitted its author to inscribe of steam alone. place than is here assigned him, they will be to him the account which he published of It has been found by experiments, that the better understood by a reference to the enhis contrivance, under the title of "The pressure of the atmosphere is equal to about graving, (see following page,) and the deMiner's Friend." 14 pounds weight upon every square inch, scription of it, which follows nearly in hist The great fame of the Royal Society, so that supposing the superficies of the own words. It is doubtful whether Hulls then adorned by the presidency of Sir Isaac aperture of the vessel, to contain one square ever proceeded beyond printing a descripNewton, made its opinion to be listened to inch, the power exerted by the steam in tion of his project. with profound respect in matters of science raising C to H will be tantamount to rais- "a, chimney coming from the furnace; and mechanics. To that body also Cap-ing 14 pounds weight that height, together b, tow-boat; c, c, two pieces of timber framed tain Savery carried his invention; and in with the power necessary to overcome the together to carry the machine, d; x, y, z, their transactions for that year is a record of friction and weight of the piston C, in the three wheels on one axis to receive ropes, his successful experiment, made in their cylinder; and that the power exerted by the s, t, u; t, being rope that goes into cylinder; apartment, and a view and description of steam in expelling the atmosphere from the m, n, two wheels on same axis with the fans, the machine forms the subject of an engrav-space E, and obtaining its consequent pres-i, i, i; u, is a rope going from wheel, n, to ing in their annual volume. sure to the raising of 14 pounds from A to; that, when the wheels, x, y, z, move for For more perfectly illustrating the mode in C; and that the disposable power, obtained ward, moves wheel, n, forward, and the fans which steam operates, we will suppose the by the return of the piston from H, will, in along with it; s, a rope going from wheel, vessel, represented in the following figure, to the first instance, be equal to the raising of m, to the wheel x, so that when the wheels, be filled with water up to the line A, and the 14 pounds weight from C to H, less the x, y, z, move forward, the wheel, m, draws space E occupied with air, and amount of the friction of the piston C; and, the rope, s, and raises the weight, g, at the having a plug or piston fitting it at in the second, will be equal to the raising of same time as the wheel, n, brings the fans C, and an aperture at D; now, if 14 pounds weight from C to A, less the forward. E the aperture D be closed, and amount of the friction as before. In both "When the weight, g, is so raised, while heat applied to the water, as at F, these instances the expansive or direct force the wheels, x, y, z, are moving backward, the steam will be generated, and by of the steam has only been considered as rope, s, gives way, and the power of the D its expansive force will raise the equal to the displacing of the atmosphere, or weight, g, brings the wheel, m, forward, and piston C upwards; then, if the what will be equal to 14 pounds pressure on the fans with it, so that the fans always keep heat be withdrawn, and the vessel each superficial inch; but if the piston C be going forward, notwithstanding the wheels, A suddenly cooled, condensation loaded with any weight, the steam will, if x, y, z, move backwards and forwards as the will take place, the steam, re-urged with sufficient heat, raise it, always piston moves up and down in the cylinder: assuming the form of water, will premising that the vessel is strong enough o, e, teeth for a catch to drop in from the again occupy the space below the to resist the increased pressure. Suppose axis, and are so contrived that they catch in line A, and the piston C will re-C to be loaded with 10 pounds of weight, an alternate manner, to cause the fans to turn to its place. In this experiment the ex- the steam must be urged until its pressure is move always forward; for the wheel, m, by pansive force of the steam compressed the equal to 24 pounds, 10 pounds more, 14 the power of the weight, g, is performing its air in the space F, and forced the plug C pounds the pressure of the atmosphere on office while the other wheel, n, goes back, in upwards, we will suppose, to H; but C, in each square inch, and the resulting disposable order to fetch another stroke. The weight, travelling to H, displaced so much of the at- force will be equal to 24 pounds more, the g, must contain but half the weight of the mosphere as occupied the tube from C to H; weight of C, less its friction returning to pillar of air pressing on the piston, because consequently, the portion so displaced will the place from where C was raised; so that, the weight is raised at the same time as the seek to resume its natural position, and when in this case, the pressure on the internal sides wheel, n, performs its office; so that it is, in the force of the steam is withdrawn by con- of the vessel, tending to burst it, will be effect, two machines acting alternately by densation, the weight of that portion of the equal to 10 pounds per square inch of the the weight of one pillar, of such a diameter atmosphere will again return the plug C to internal superfices, the remaining 14 pounds as the diameter of the cylinder is." Hulls, its place; by which it is obvious that the being counteracted by the pressure of the aware that objections might be urged against raising of the plug was the direct action of atmosphere on the external surface, which its want of originality, endeavors to anticipate the steam, and the returning its consequent is equal to 14 pounds of the internal pres-them: "if it should be said," says he, "that action, or the action of the atmosphere, in sure. By this, it is evident that the direct this is not a new invention, because I make consequence of its having been displaced by force of steam may be increased without use of the same power to drive my machine the force of the steam. limits, whereas the resulting force or pres-that others have made use of to drive theirs Again, if we suppose the plug to be in its sure of the atmosphere is manifestly bound- for other purposes, I answer, the application first situation, as at C, and we open the aper-ed to 14 or 15 pounds on the square inch, * A description and draught of a new-invented machine ture at D, and apply heat, the steam will according as its density varies. rise into the space E, and expel the air A mode of applying the power of a steam-or river, against wind or tide; or in a calm. London, hrough the aperture D, which being closed, engine to navigate a vessel was suggested forty-eight pages, about eight of which have any reference nd condensation caused, the space E will" by Jonathan Hulls in 1737.* But the scheme, to his invention. Hulls took out a patent. for carrying vessels or ships out of or into any harbor, port, 1737. It is a pamphlet, by no means scarce, containing |