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ELECTRICAL THEORY OF THE UNIVERSE.

407 purpose of throwing a stumbling-block if there is a retaining force, and the in the way of Mr. Mackintosh. I trust power of that retaining force is overcome I may be in error; for the legitimate by electricity, then the cause of elecaim of all controversy is the attainment tricity must be material; and, as the reof truth; and this aim cannot be accom- taining force was overcome by the elasplished by a subtle and ingenious sys. ticity of that material something, I tem of special pleading, pressing into ask, whether it is more philosophical to our service the opinions and assertions of deny, or to admit the claim of electricity others, not because they coincide with to the title of a material duid. The our own ideas, but merely because they learned professor amuses himself at the militate against those of our opponent. expense of the blindness of those who But to the point.

complacently deseribe the play and vaI confess myself to be an humble in- garies of an electrical current whose existe dividual of that humble class of rea- ence was never proved.To this I shall soners, alluded to by the learned pro- not add an observation, but content myfessor, who conceive that the cause of that self by supposing that, at the time it by which sensation is affected, and a was written, the new wonders of the material impulse experienced, must it- science of electro-magnetism had not self he material ; and that as

yet penetrated so far north as the modern tion is affected by, and a material im- Athens, and by assuring Kinclaven that pulse experienced from electricity, the numbers of scientific men, whose names cause of electricity is corporeal; and, I am not worthy to mention, will peruse further, that as it possesses, in an emi. the learned professor's observation with pent degree, the properties of a highly greater complacency than their elastic fluid, we humble class of rea. countenances assumed when they de. soners must be content, in our darkness, scribed the " vagaries of an electric curto consider it as such, until Sir John rent.” The learned professor proceeds Leslie, or some other philosopher, proves to slate, that “ we are acquain:ed only. the contrary. For, after all, to what do the with electric attraction and repulsion, learned professor's observations amount? and with the transmission of electrical He wishes to ohject to and set aside a influence, and that all beyond this rests theory, not only without substituting a on hasty conjecture !” Now, if Kinmore satisfactory one, but without fa- claven will inform us what is the transvouring us with any other! unless, in- mission of the electrical influence, and deed, the unintelligible sentence with how it is effected, I shall be happy, also, which the extract given by Kinclaven tu reply to this. In the mean time, I may concludes, be an attempt at such substi. add that by far the great majority of tution. If so, I ask Kinclaven to state electricians believe the phenomena of candidly whether he comprehends the electricity to be produced by a subtle learned professor's meaning. It is impos- fluid, or by two Auids. And, unsatissible; for I think it would be no very dif- factory as our present theories may apficult matter to prove, by the professor's pear to be, we must be content with own words, that he did not understand them until a more satisfactory theory is it himself. What, for instance, is the framed. meaning of the “colour of emission !" I beg leave to assure Kinclaven that And what the explanation of the asser- these observations are not the result of tion, that the “colour is modified by the any wish to take a part in the contro. peculiar character and intensity of the versy respecting Mr. Mackintosh's theory; retaining force ? What is retained ? believing, as I do, that, in nire cases out and what force is here alluded to? To of ten, controversy tends rather to rethe former question, I presume the re- tard than to advance the true interests ply is, “the particles of light," which the of science. I have, and trust I ever learned professor speaks of in the same shall keep, but one object in view-the senience, as being " disengaged from the attainment of truth. surface of the conductor." This light, Before I draw this letter to a close, I then, according to the learned professor, may congratulate myself, in being able is not the electric light. And this ma. to unite with Kinclaven, in his admiraterially weakens his own position. For tion of our great Newron. He, at least,

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Kinclaven will readily admit, was a man not given to “hasty conjecture." I cannot, therefore, more appropriately conclude this tedious communication than by referring him to Newton's “Op. lics,” (8vo. edit., pp. 324 and 327,) by a perusal of which he will learn it was the opinion of that philosopher, that electric hodies, when excited, emitted an elastic fluid.

Yours, &c.

WILLIAM LEITHEAD. 22, Compton-street, Brunswick-square

12th September, 1836.

OF

AERIAL NAVIGA

PREFERABLE

IMPRACTICABILITY

TION MONTGOLFIER's
TO GAS BALLOONS.

Sir,—The subject of aerostation has been more fully and better discussed in your periodical than in any other; but although your intelligent correspondents bave, during the last twelve years, supplied you with numerous observations and ideas on the subject, nothing essentially new or important has been elicited, This comes from the sterile nature of the thing itself. No one, as the homely saying is, can “make a silk purse ont of a sow's ear.” It is quite astonishing to observe how so many men of good sense can talk of propelling and directing a balloon through the air, on principles derived from “ the way of a ship on the sea!” A vessel either on or in a mass of water can be propelled even against a current of that water, because the density of the medium allows of a power being applied of a velocity within the reach of our physical organs do produce. But for a power to be applied (in an analogous way) in the car of a balloon, against the air, in which the whole machine is immersed, it must have six hundred times the velocity of the stroke which will produce the same effect upon the water. Soune persons say,

we will take up a steam-engine," &c. But the more weight you take up, the greater must be the dimensions of your balloon! After allfor it is loss of time to argue such a matter—it is evident that no power can draw a balloon against the slightest zeplıyr, but one which would place the car and the balloon on an horizontal line together, like a horse drawing a cari! With regard to the elongated and fish

like shapes that have been so often proposed, the fallacy is still mure afflicting. When there is no power of propulsion through the fluid, low can the position of the elongated body be decided ? Even a barge going down a river along with the stream has not the least power of steerage by the rudder, because it does not go through the water, but with it: without external power applied, either of traction, oars, or wind, it goes along sideways, or any way, just as it may happen. Another fallacy in the ideas connected with an elongated fish-like balloon, is also of a serious nature, setting aside the physical impossibility of propelling it. How is it to be kept in a horizontal position ? A halloon of such a shape (like Egg's, the Pall-Mall gunsmith, or of Col. Lennox's “AerialShip''), being filled with gas and set up without any load, would certainly be liable to rise in any way but the one desired. If to prevent its bursting by the expansion of the gas, it were only three quarters or two-thirds full, it is ten to one but that it would rise up endways. If a net, car, &c. were to be attached to it, with a load of passengers, it would double up into the shape of a crescent; that is, if the gas did not rush to one end (which is most likely), and so defeat all the fishlike calculations of the constructors! A stout back bone to the fish-balloon might prevent the doubling up I speak uf, but it would not save it from the chance of going up end ways, much to the inconve. nience of the travellers in the car beneath. But it is absolute waste of time to dwell on such nonsense. It is a pretty thing to see a balloon ascend when you are near it at the time, and will answer the purposes of the proprietors of public gardens, &c. The near view of any large mass in motion, such as a ship launched, a huge tree falling, &c. convey a novel and peculiar feeling to our senses.

In 1810, Madam Blanchard, the widow of Blanchard who, with an Englishman, crossed in a balloon from Dover to Calais, arrived at Naples with her balloon. An ascent was ordered by the King (Murat) to take place from the Campo Marte, on an occasion when there was to be a grand review of troops. In consequence of my known chemical propensities, the King ordered the talented Giovanni Dall'Arini and myself to make all the preparations,

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and superintend the inflation and ascent liable to accident than the other, which is of the balloon. It was settled that I was liable to burst, or to be ignited by an electo have ascended with Madan Blanchard; trical discharge from the clouds, or to but owing to the exhibition having been fall too rapidly through any over-opening counterianded on account of the weather, of the valve. The flame from the fireafter operations had began, and then re- place of a Mongolfier balloon ascends ordered, the balloon was not sufficiently vertically into the interior without the buovant at the hour appointed to carry slightest vacillation. The flame of a two persons, so I, to my great chagrin, candle in the car of a gas balloon could was left behind. Madam Blanchard nut move were it blowing a gale of wind, had in her possession a Mongolfier bal- hecause the balloon goes with the wind. loon, which she sold me for 401. But still less can the flame in the interior With that balloon | purposed making of a Mongolfier balloon waver. a series of experiments upon that principle tect the cotton tissue of the balloon from alone, of which, in my opinion, balloons sparks, it is quite sufficient and effective can ever be made to take advantage, to saturate it with a solution of alum. which is, various currents of air crossing The circumstances through which I lost each other at different elevations in our my Mongolfier balloon, before it came atmosphere.

into my possession, are not worth detail. A balloon filled with hydrogen gas, ing. It was seized at the Turin customprovided with sand-bags for ballast, &c. house as English cotton goods. 1, howcan only rise by throwing out ballast, ever, made a smaller one myself, by and descend by allowing an escape of experimenting with which I have arrived gas. It is evident that these operations at the above conclusions; but shortly havcannot be repeated beyond a certain ing other things to attend to, there ended limit, because you have no means of re. my ballooning project. But if any one plenishing the ascending power. A Mon- would now be at the expense of construct. golfier balloon is inflated and rendered ing such a balloon, I should be very buoyant by means of flame, just like the happy to furnish him with my modicum paper “ fire-balloons” of our tea-garden of knowledge and assistance on the occaeviertainments. A Mongolfier balloon, sion, and be the first to make a demonmade of cotton “ broad cloth,” forty feet stration of that which I conceive to be the diameter, will

carry up

four
persons.

A best method of ascending and passing circular grate or fire-place, of three feet through the air by means of a balloon. in diameter, is suspended concentrically Marshal Jourdan was commander-inin the inferior opening of the balloon ; chief of the French army in Flanders which opening is about seven feet in dia- when a balloon was made available to meter. Around this opening is a wicker the taking of all the plans of the enemy's gallery (instead of a car, as in the gas lines. I have conversed with him at balloons). The persons in this gallery, length on the subject, and he allowed being provided with a store of litile fag that a Mongolfier might be constructed, gots of dry wood and a long-handled filled, elevated, and applied to all such fork, keep up the fire by supplying it purposes, when it would be inpracticable with fuel. When it is desirable to de.

to procure hydrogen gas, or a balloon scend, the fire is allowed to wane; an sufficiently impervious to retain it. The increased fire occasions a rapid rise. Mongolfier requires no varnish.

Gas Thus it is absolutely at the discretion of escapes through all those hitherto applied. the aeronauts to rise or fall, as long as Almost the only useful purpose to their fuel endures. The fire-grate is which I could thivk of applying an hyprovided with a hinged cover, so that it drogen gas balloon would be the esta. may be extinguished at once, or the bot. blishment of a communication belweeu a lom of the grate may be let out, so as to stranded ship and a lee-shore. About vacate all the fuel. With such a bal. three years ago I addressed you a letter loon, even when the fuel is all expended, on that subject, but I cannot say in what a fresh supply may be had almost any Number it appeared.

I gave you a de where; and thus the search after various tailed description of the apparatus recurrents of air may be far more success. quired. The Portable-zas Company coinful than with one of hydrogen gas. I press thirty volumes of gas into one, into look upon the Mongolfier balloon as less vessels of thin sheet-iron with ovoidal 410

MR. GREEN'S ACCOUNT OF THE ASCENT OF THE GRAND BALLOON.

ends. Such a vessel charged with one of the workmen in the gardens were hundred cubic feet of the best gas, might called to the assistance of the police. easily be fitted into the bottom of a large The rain now fell in torrents, and the cask. The empty balloon being placed netting and silk must have absorbed at over it, and communicating by a tube and a moderate calculation 300lb. weight of stop-cock. In the same cask might be water, besides the quantity retained on arranged a long cord of the lightest and the top of the balloon by the pressure best materials. The whole apparatus,

of the net on the silk, each mesh forming properly made and packed, would always a small reservoir. At a quarter past four be ready on deck like a mere water-cask. the inflation was completed, having occuThe balloon once up, by adding more pied, and under these unfavourable cire rope to the thin one belonging to it, cumstances, only five hours and fire piust come at last into contact with the minutes. I had supposed five hours edge of a cliff, or with the surface of any would have been the time required, but lee-shore. The balloon might also be I now believe four would be sufficient ou made to take up a sinall grappling, com- a sunny day. The process of attaching posed of three or four shark-hooks tied the car to the net was commenced, and, back to back. I fear, however, that there from the shrinking of the ropes by the would be considerable risk of the bal. wet, and the necessary adjustment reloon's being torn by the yards, &c. of quired at the first ascent (which cannot the ship before it could be got clear of it. be done until the balloon is inflated), In the case of a low coast without cliffs was I fear somewhat tedious to the comor high rocks, an empty water-cask, pro- pany, but the ropes being now cut to the tected by sacking, &c. wouid take a line proper lengths, this will be for the future on shore as well as a balloon. Apropos of effected very quickly. Twenty-four bags water-casks and provision-casks, I have of ballast, weighing together 40016., suggested many years ago, that is, as being placed in the bottom of the car, these become empty, they were to be my companions, with the greatest alacrity, bunged up and slowed so as not to be obeyed my summons, and took their seals; washed away, their þuoyancy would pre- they were Mr. Hildvard, Captain Currie, vent the vessel from sinking even when Mr. Holland, Mrs. reen, Miss Green, she were full of water. All the trouble Mr. E. Gye and Mr. W. Hughes (sons is in well bunging up the casks when of the proprietors), and Mr. James Green, they become emply.

my brother, making in all nine persons, Yours, &c. F. MACERONI. myself included. September 10, 1836.

I had calculated the power of the

balloon according to the average specific MR. GREEN'S ACCOUNT OF THE ASCENT OF

gravity of the gas made by the different

companies, and found it to be considerTHE GRAND BALLOON FROM VAUXHALL.

ably more than has been stated in the The inflation of the balloon commen- advertisements; but it was the wish of ced at 10 minutes past 11, on Tuesday, the proprietors and myself to underrate, September 9th, and in the space of 12 rather than overrate, its capabilities, minutes it possessed sufficient power to in order that the public should in no support itself. Thirty-six men of the case be disappointed, but, on the con. Lambeth division of police were then trary, unless some unforeseen circum. placed around, each taking charge of stances occurred, be surprised. Howone of the cords connected with the net- ever, owing to the exertions made by work. In about an hour an iron weight Mr. Hutchinson, engineer 10 ihe London of 561b., provided for the purpose, was Gas Cumpany, and his judicious aralso attached to each cord, and shortly rangements in the manufacture of the after five more at different parts, making gas, even my own expectations were in all 41 weights of 561b. each. These surpassed, and I was obliged to allow were soon all lifted three feet from the about 15,000 feet of gas (equal to oneground, and the policemen were obliged fifth power of the whole) to escape before to pass their staves through several of I could release the machine from the the meshes to prevent the cords cutting moorings, the ascending power being their hands. This enormous combined much too great, and no room being left resistance was found insufficient, and 20 in the car for many more passengerse

THE HOUSE-BURNING SYSTEM

411

We proceeded at first to the east, but soon took a sonth-easterly direction, leaving Greenwich and Woolwich to the left. The gardens, and every avenue leading to them appeared to be one solid mass of human beings; in fact, there was not an elevated spot within two miles of the metropolis which was not crowded with spectators. We had ascended about three quarters of a mile, when we found ourselves in a brilliant sunshine, which formed a strong contrast to the dense and clouded atmosphere we had just left. The gas now expanded rapidly, and the silk down to the bottom of the neck was completely distended; we, of course, ascended with great velocity, and in less than five minutes the fall of the mercury in the barometer indicated a height of iwo miles and a-half. This was our greatest elevation, and, it being nearly dark, I thought it unadvisable to ascend higher; therefore, suffering a small portion of gas to escape from the valve, we commenced our descent. We were now nearly opposite Gravesend, and had crossed the Thames several times: the grappling iron or anchor first touched the ground near the village of Cliffe, in Kent, and after slightly catching several times, took a firm hold; a slight breeze springing up at this moment, the jerk caused the hoop, to which the grapple cord was attached, to give way, which rendered it necessary to open the valve very wide.

This done, ihe car soon touched the ground; we then drifted about 100 yards, and, the valve being kept open, the stupendous machine, which so lately exhibited its giant power, lay motionless on the ground.

All my companions expressed the greatest delight during the voyage, and enjoyed themselves much ; indeed, so loud was their mirth several times, that I had some difficulty in making my directions audible, for I assigned a duty to each, suchas watching the rise and fall of the mercury in the barometer, and thermometer throwing out ballast, &c. Being forced to take such a large quantity of ballast, we found the too small, but a new one much larger car will be constructed for the next ascent.

We slept at the village of Cliffe, proceeded to Gravesend yesterday morning, and arrived in town at 10 o'clock last night.-- Times.

THE HOUSE-BURNING SYSTEM. The immense amount (between 400,0001. and 500,0002.) of property destroyed at the late fire in Tooley-street-about 100,0001. of which falls upon the Sun Fire-office alone may perhaps cause some energetic efforts to be made for the employment of more efficient means than have been hitherto adopted either of putting out fires or of arresting their progress, if not of preventing them altogether. The effect of the system of fire-insurances, like that of the Drowning at Sea Society, has been to perpetuate the evils it was intended to avert: individuals are secured from pecuniary loss, but burnings and drownings continue. With such a vast amount of capital, and so many practical men engaged in the business of preventing and repairing damage by fire, it is surprising that in the present improved state of mechanical science no mode should bave been discovered of extinguishing a burning house. Our engines do not put out fires, but only keep them from spreading, with the aid of party-walls: where these are wanting, the only preventive means is to isolate the fames by pulling down adjoining buildings. We laugh at the Turks, who suffer whole streets of houses to be burnt down, and then quietly build them up again of the same inflammable materials; but we are not much wiser in our generation. Our buildings are not quite so quickly destroyed by fire, but they are scarcely less easily set light to, and their ultimate destruction is hardly less certain. Cast-iron beams and columns and stone-staircases may be employed, but there is enough wood used in the construction of buildings to carry the fire from room to room and from floor to floor; and the shell of brick that remains is only a dangerous ruin. Surely some plan of building might be adopted, by which a fire breaking out in any one apartment would be confined to it. This, however, is an ulterior consideration : the more immediately important point is the means of extinguishing fires that break out in buildings as at present constructed. Every one must bave been struck with the absurdly inadequate powers of our fire-engines: it would be ludicrous, were it not a melancholy sight, to see a score of men panting and toiling to squirt a tiny stream of water on to a blazing house-it rather augments than helps to quench the flames: a dozen such jets playing at once can produce very little effect on à great body of fire; the immense heat converts the small quantity of water that comes in contact with tbe flames at one time into gas that adds fuel to them. The utmost that the best served engines can do to stop the progress of the fire, is by saturating the adjoining buildings with water, or quenching parts partially ignited, or half burnt out: to quell a body of flame such as a

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