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09211797 voy a baarsteeg ! Not if fariz bever. boud of scalon! Slide 1990tsd siis


ETTU to Sir,—The following is a description of A ; now there is attached to the piston, a rotary steam-enzine, which I think and constantly moving with it, a true segpossesses many advantages over any that ment of a circle made of brass, and I have yet seen, and obviates all, or rather longer than half the circumference most of the objections which present of the cylinder, a little wider than the themselves in these kind of engines. A opening, and fitting into a 'groove on is an annular cylinder, part of which is each side, made steam-light by the presrepresented as broken away to show tlie sure C within. When the piston has piston and one of the sliding abutmenis. passed the abutment, the steam is reBB are the steam-ways from the slide- versed, and the semi-circular biass passbox D and steam-pipe C; E is the work- ing the other abutment, allows tlie sream iny shaft firmly fixed to the piston F; that bas done its office to escape into the GG are the sliding abutments and cases, atmosphere. Of course the sketch is a which are kept in their places by a sulfi- high-pressure engine, but it may be made cient pressure of steam, a spring, or a a condenser by boxing in the cylinder, counterpoise (not necessary to be shown), and having a stuffing-box round the main so that when the inclined plane on the shaft, and conducting the 'exhausted piston F has pushed it up and has passed, steam to a condensor. This kind of roit immediately returns or shuts into its tary-engine is a direct accelerated motion, place again, having meantime reversed no stoppages, and there is nothing lefto the slide-valve, and admitted the steam for the inomentuni of the fly-whrel 10 between the piston and itself, while the perforni, milie steam is always acting. communication on the other side is cut It can be made either tu advance or redu! off. H A are the supports to the levers trograde, merely by having an inclined IT, which, in conjunction, work the plane on each face of the piston, and slide valve by the continuous rod K K. having the semi-circular brass to work It will be understood, that to allow the easily through a guide in it, and being arm E and piston F to perform their re- fitted with iwo proj«ctions, as shown by volutions, there must necessarily be a suf- the dotted lines, supposing it were reficient opening right round the cylinder quired to reverse the motion as shown in



the figure, the steam is let in, the piston of information which, when represented and shaft retrograde, and the brass (or in the proper quarter, may prove useful; seini-circular valve) resnains stationary and freely accepting Mr. Howard's apotill it is dragyed round by a piston striking logy, the projection on the opposite side. This

I remain, Sir, is the engine, Mr. Editor, which, if you

Your most obedient servant, remember, I made a self-exacted promise

WILLIAM SYMINGTON. long ago of forwarding for insertion in

1, King William-street, London Bridge, your useful pages; but many circum

September 1, 1836. stances combining to drive the thing out

mind at the time, I had nearly forguiten till a few days since. I should


DROGEN AND CARBONIC ACID GASES. be glad of the opinion of some of your practical readers on the subject, and beg io state, that if the idea be of use to any person, it is at his service.

I am, &c.

W. PEARSON. Biskop Auckland, June 7, 1836.

of my



Sir,-Having perused Mr. Howard's rejoinder contained in your last Number, and observed that it embraces no new facts inclining me to believe that the difference between his meihod and mine is quite immaterial, I cannot perceive the propriety of occupying your valuable pages in useless controversy, particularly when an examination of the drawings accompanying our specifications will at once slow the wide dissiinliarity of the plans in question.

To relieve Mr. Howard from suspense on one point, I have to arquaint him that it was my brother, a resident in Scotland, but then on a visit to London, who called at Rutberhithe. But concerning that call I can truly say, he never mentioned a

5912 single syllable of having seen or heard of any particular plan of condensation. In reply to Mr. Howard's questions, I

199 have merely lo observe, that what he terms his method or principle, described in italics in his last communication, has been in practice for foriy years; and

ti kartano should he have any anxiety to see it in Sir, I take the liberty of sending you operation, I am ready to direct him to the following description of a machine where he may satisfy himself.

which has occurred to me.

Should you I was not altogether aware, until Mr. deem it worthy of insertion, it may at Howard has been pleased to inform me, least suggest an improvement in balloonto what cause to attribute the being de- ing. prived of the Comet, and put to so much

I am, Sir, expense and inconvenience before I could

Your most obeclient servant, even get the wheel tried with a vessel,

ROBERT MUNRO. the Alban, for which it had not been August 24, 1836. constructed. Thanking him for a piece In the accompanying figure A is a


ON AEROSTATION. balloon of the common form and material cured, and at an expense far below that filled with coal gas. B is another of of coal gas or hydrogen. smaller dimensions filled with carbonic acid gas, until its weight is nearly suffi.

ON AEROSTATION. cient to prevent the rising of the machine; C, a car suspended from the upper balloon Sir,-Having, in my letter of the 1st ult. in the usual way; D, a slender steel-rod, (see p. 307,) endeavoured to show the or a rod of twined bamboo canes passing improbability of aerial machines tending perpendicularly through these and fast- to


purpose, while they retain ened to the silk at A and B; E, a sail their present form, I shall now add a few fixed to D; close to the ends of the rod remarks, suggesting the form in which there is a valve at each extremity opening balloons ought in my opinion to be made. inwards, and acted upon by a cord run. In art we generally imitate the works ning alongside the rod and affixed within

of nature; now, all animated bodies in. the car.

tended for locomotion in the air or water This machine does not require much have a head and a tail; man has imitated explanation here; it need only be said, this in the ship, which has a stem and a that while the contents of the upper bal. stern; but in the balloon he has neglected loon are nearly the lightest of aeriform his model, as at present made they have fluids, those of the lower are the heaviest ; neither, and to this their mal-conforma. consequently they will each exert a power tion alone must be attributed the repeated acting differently. When the machine is failures that have taken place in all at. afloat in the atmosphere, by permitting tempts at guiding them. Upon this, I a certain quantity of gas to escape through found the following observations :the upper valve, this will diminish the as- Balloons have two motions, a vertical cending motion, which then yields to the and a horizontal; the former caused by heavier, and by acting similarly upon the the levity of the gas contained, and the lower valve a proportionate quantity of latter by the prevailing current of air in the carbonic acid gas will fall down and which it ranges; and this latter is the the effect will be reversed ; and by a nice movement that requires to be regulated, adjustinent of both the powers, may be as the other can be varied by retaining or made to balance, and the machine will discharging of the gas or the ballast. become stationary at any

elevation. Now, when it is considered how readily Now, as the rod is continually kept in a vessel answers to her helm, and that a perpendicular position by the opposing water is to air as 832 to 1, I cannot conpowers, and as the whole are connected ceive that it would be found so difficult a together and kept uniform by it, it is task to guide an oblong machine in such a obvious that when the machine is station- yielding element as atmospheric air. I ary it would move horizontally before ain aware that many scientific persons any force opposed to it, consequently a think differently; I would call the attensail might be applied, though the surface tion of such to an account in the daily of the machine itself might be sufficient papers, not many months ago, of one of to cause it to move before the wind. his Majesty's ships, after losing her rud.

The above arrangement would be very der and a temporary one in a hard gale of suitable for taking plans and bird's-eye wind of several days' duration, having views. It is in the power of the voyager been steered up the Channel to Spithead in the ordinary balloon to cause it to rest by only attending to the trimming of her at any elevation, but this only by a very sails;—there are also other known modes inconvenient process, and one that is not of steering by the assistance of the wind always practicable, but this advantage is alone. In short, I am doubtful whether possessed by the present to such extent, machines to float in the air should differ, that the mere adjustment of an index except in the materials for their construc. may cause the effect; but all independent tion, from those used to float on the of the safety of it, which would bear the water.* most severe breeze as its becoming disarranged or tossed, would be impossible. * In comparing aerial with marine navigation,

I may mention, though well known, the fact is generally lost sight of, (as in the present that carbonic acid gas is most easily pro.

instance by “Omri,'') that in the latter case the vessel floats in one medium and is propelled by the


395 It is common with aeronauts now to the same quantity of pure hydrogen gas, ascend to a most unnecessary height for about 364 lbs.; the machine would col. any experimental purpose : if ascensions sequently, if inflated with that gas, have were confined to a moderate height, suffi- an ascending power of 4982 lbs.; and cient for all the ordinary purposes , of allowing 700 lbs. for the weight of silk voyaging, descents might generally be and apparatus, and 362 lbs. for ballast, more safely and rapidly effected in cases would be capable of ascending with 28 of danger. With respect also to the pro- persons of the average weight of 140lbs. posed enlargement of balloons, I would each. But Mr. Green in his first expeask, are not two or three persons suffi riments in aerostation, seeing the great cient for philosophical or experimental expense, difficulty, and inconvenience of trials ? First let the aeronauts show the using pure hydrogen gas, conceived the capability of guiding them, and capa- possibility of substituting carburetted hyciousness may then follow. When an- drogen or coal gas, such as is used for nouncements like those of the proprietor illumination; and first used it in his of the " Eagle" and her seventeen pas- balloon which ascended on the day of sengers are made, I augur unfavourably the coronation of George IV. From that of their performances adding much to time the use of pure hydrogen has been our slock of knowledge. Proofs of the almost, if not entirely, discontinued, the points necessary to be first ascertained

expense of generating it being six times might be made for a tithe of the money greater than that of coal gas. The spe. that must be expended in making a bal- cific gravity of coal gas being considerloon of the magnitude of that now about ably greater than that of hydrogen, it to ascend from Vauxhall; for the fate of gives a balloon a much smaller ascending which all thinking persons must feel some power; and the quality of coal used, and apprehensions, notwithstanding its being the methods employed by different gas under the guidance of the most expe- companies in its manufacture are so vari. rienced aeronaut of the day.

ous (the specific gravity having been I remain, Sir, yours, &c.

found to vary from 340 to 790), that it OMRI.

is impossible to ascertain exactly what London, September 4, 1836.

would be the power of a balloon inflated with it. It is, however, calculated that

the new balloon will ascend with from MR. GREEN'S GRAND NEW BALLOON.

eight to ten persons, besides ballast and This balloon, which, notwithstanding

apparatus ; the power varying according its great size, is inferior to the French

to the quality of the gas, the state of the aerial ship, which was exhibited at Ken- atmosphere, and a variety of causes. As sington some time ago, has been con- a matier of curiosity, it inay be stated, structed under the immediate superin- that the inflated silk will susiain an atinotendence of Mr. Green, the most expe- spheric pressure of 20,433,600 16s., or rienced aeronaut of the age, he having 9122 tons. The net which entirely enmade 220 ascents; the following parti- velopes the silk is of hemp, and the car culars have been published with respect of basket-work; the grapple or anchor, to it.

It is 157 feet in circumference ; is of wrought-iron, and will be attached and the extreme height of the whole, to an elastic India-rubber cord from the when inflated, and with the car attached, factory of Mr. Sievier. This will prewill be 80 feet. It is formed of 2000

vent, in a very great measure, any suda yards of crimson and white silk. The me- den jirk in stopping the balloon in rough ihod of uniting the gores (the invention weather, whereby so many accidents have of Mr. Green) is by a cement of such a occurred. tenacious nature, that when once dry, The following are said to be among the the joint becomes the strongest part. It advantages to be gained from the large contains 70,000 cubic feet of gas. The size of this aerostatic machine :- A much weight of atmospheric air sufficient to greater elevation than has hitherto been inflate it, is about 5346 lbs.; and that of attained, and the long agitated question

decided as to whether there are, at a

great altitude, currents of air proceeding help of another, whilst in the former it floals in, and is propelled by, oue and the same medium.

in one direction for several months to.


SULLTZ'S RAILWAY-CARRIAGE SPARK-ARRESTER. gether. This Mr. Green, from many oh. purpose, the one now before the Committee servations he has made, believes to be resorts to the use of the wire-gauze for inter. the case at an altitude where the atmo- cepting the sparks. sphere is not acted on by the reflection of But instead of having it on the top of the the sun's rays from the earth, or dense chimney in the form of a bonnet or cap, it is masses of clouds. Should this theory be interposed in a horizontal plane near the botfound correct, a grand step in the pro.

tom-a conical enlargement in the chimney gress of aerostation will be made. The being provided at that place to allow a suffi. great power of the machine, even when

ciently extended surface for a free passage of

the smoke and heated air. inflated with coal gas, will enable scientific genilemen to ascend with pliilosophi. A small door in the side just above the cal apparatus, for the purpose of making gauze commands a view of the whole surface experiments on electricity, pneumatics, of the gauze for the purpose of cleaning, &c, magnetism, &c. or astronomical observa- The advantages of this arrangement are evitions, which, from the small dimensions

nently three.fold. First, in admitting the of all other balloons, has heen impossible;

escape-steam to be discharged above the and this circumstance has caused them to

gauze by the pipe passing through it in the

middle, thereby avoiding the serious incon. be regarded by scientific men as mere

venience of the meshes becoming choked by ohjects of public exhibition. A small

the combined effect of soot and moisture, chainber to be atiached, in place of the which is felt when the steam is discharged be. car, is about to be consiructed for the

low it. Secondly, in a better disposition of above purpose, in which from three to six the weight of the apparatus, which in the persons can ascend, with ample rooin and ordinary mode makes the chimney top heavy. every convenience for experimental ap- And, thirdly, in having all within convenient paratus.

reach of the engineer. Besides the main,

there are three considerable flues, which are Mr. Green is, after all, cf opinion, that

occasionally opened by slides which draw aerial navigation is totally impracticable horizontally for that purpose. These flues to any exient.

are on different sides of the chimney, passing The tenacious cement above mentioned

outside of the sheet or disk of gauze, and we suppose to be dissolved India-rubber,

serve to give additional freedom to the pasabout which Mr. Green said so much in

sage of heated air and smoke, whilst the fire his examination on the Patent Caoutchouc

is starting. In an apparatus of this kind,

which the inventor stated had been tried on Case, Macintosh v. Everington and Ellis,

the Germantown-road, the enlarged diameter Should this be the case, we have our

of the chimney was three feet in the clear, fears for the safety of the aeronauts. If whilst that of the chimney proper was of the the balloon, as is usual, he covered after usual size of fifteen inches. The inventor being finished with a coating of mastic likewise stated to the Committee that the exvarnish, this will destroy the tenacious periment was entirely successful so far as a property of the caoutchouc, and unless single trial could be depended on. The Comihe gores are also sewn as well as cemenied,

mittee are aware that the principle of placing there is great danger of their giving way,

the gauze below the point at which the escapesteam is discharged has been before attempted by putting it in the smoke-chamber. The

ohjection to this plan seems to have been a SHULTZ'S RAILWAY CARRIAGE SPARK

too rapid destruction of the gauze by the

heat to which it was exposed-a fate which Report of the Committee on Science and the

it is feared in some degree awaits the present Arts, constituted by the Franklin Institute

invention. But from the facility with which of the State of Pennsylvania for the Pro

the gauze can be replaced by removing the motion of the Mechanic Arts, to whom was

upper section of the chimney, the opinion is referred for Examination a Spark-Arrester,

entertained that this will be found the best invented by Mr. William Shultz, of Phi

arrangement which has yet come to the know. ladelphia.

ledge of the Committee for the accomplish

ment of this difficult desideratum. That they have examined the plan of Mr. Shultz for arresting the sparks from locomo

By order of the Committee, tive-engines, and that its principal features and mode of operation are as follows:

WILLIAM HAMILTON, Actuary. As in most other contrivances for this March 11, 1836.


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