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TOE DATY-LANP. ship-like car, which was to have masts, when aerostation has become so popular sails, and rigging, and sailors, to ma- that ten or a dozen persons ascend with nänvre it; and, above all, metal light- one balloon. ning.conductors from the top of the masts I will.nowv, sir, make a proposal, which to the bottom of the car! Pray where I leave to your diseretion whether to did he mean the electrical fluid to go, make public or not in your Magazine. after it had travelled through the rods? Taking advantage of Colonel Maceroni's

As to the objection, that gas-balloons offer of assistance, I would propose an are liable to burst, no accident has ever Aeronautic Club," consisting of about happened in that way; although there, a dozen or more gentlemen, who, hy are several instances on record of bal. subscribing a few pounds each, might loons being rent by the extension of the have a Montgolfier balloon constructed, gas, yet they always came safely to the in which the subscribers should ascend by ground, the flaws being only large enough turns, to he decided by lot—some for to allow of a gradual escape of the gas. scientific observation, and others for mere After all, in my opinion, the two kinds of curiosity. balloons are about upon a par as regards I have made a rough calculation of the safety, and I would as soon trust myself probable expense of a balloon for such a with the one as the other.

club, and I here submit it to your readers. As a Montgolfier is, however, evidently The Colonel says, a Montgolfier, 40 feet the cheapest, I would make a suggestion diameter, would take up four persons. as to its greater security: might not that Suppose, then, we estimate for one of 50 part of the balloon in the vicinity of the feel diameter to carry five persons; the fire be made of asbestos? And, further, rule to find the quantity of cloth required, would not woollen or worsted stuff be as given in the Edinburgh Encyclopedia, less combustible than cotton ? A spark is to multiply the square of the diaineter or flame applied to the former would only by 3-1416; therefore, 50 x 50 = 2500 x singe tlie portion in immediate contact 3:1416=7851 feet = 2618 yards, which with it, while the latter would blaze up. at 6d. per square yard (a good price for

For security, in respect to both kinds colton, or bombazet as before suggested), of balloons, I would suggest that the car would be 651. 9s.; and for making say, should be so balanced that, in the event 101. Of the other expenses, the Colonel of the sphere bursting or being burnt, it is no doubt better able than I am to give would maintain an upright position in an estimate; with which he will perthe air, and fall with its boitum down- haps oblige your readers, as also with an wards. The fall would also be greatly opinion of the plan. With your perbroken by a parachute of very moderate mission, sir, your publisher will take dimensions, and on touching the earth, charge of any letter from parties desirous still further by helical springs in proper of joining the club, addressed to, positions on the bottom of the car. An

Sir, your obedient servant, aeronautic life-preserver might be made

UMBRA MONIGOLFIERI. in the shape of a loose dress attached firmly round the shoulders, stiffened with ribs of whalebone, hinged at that part;

THE DAVY-LAMP. each of which ribs should have a stay Sir,— It is evident from the commencefrom near its extremity to the waist, so ment and termination of your correspondthat in the event of an aeronaut falling ent “ Black Diamond's" letter, which out of the car, or the destruction of the appeared in your publication of the 10th balloon, the parachute dress would ex- inst., that he labours under the imprespand and bear the wearer gently to the sion that the Davy-lamp has not yet earth. A parachute of about 12 feet been proved insecure, by " the inflamdiameter was found by Mr. Blanchard to mable gas actually evolved in coal-miues.” be sufficient to bear a inan safely to the The contrary is the fact; the error geneground from any height; and M. le Nor- ral. A reference to the evidence given mand threw himself from a house, and before the late Committee on Accidents descended in safety with a parachute of in Mines, will show that the trial of that only 30 inches diameter.

lamp has not been confined to factitious These precautions should not be con- gases. Mr. Buddle's evidence, p. 154,

as unnecessary, or out of place, records its first trial and failure. He

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REST WIDTI OPORAILROAD TRACKS.: says, “I held the lamp in the direction other persons; his workmén, who signed , of the jet of fire-clamp, and not having the certificate referred 10. seen it explode before, I was not very It

may be urged, though I do not exapprehensive of its firing. It did not

firing. It did not pect it will by so intelligent a person as fire at first; but approached the end

your correspondent, “ Black Diamond,". of the pipe, the gauze became heated ihat the Davý-lamp ought to be conred-hot, and passed the explosiou. The sidered safe because it has never been flame was as long or longer than the proved unsafe in a quiescent atmosphere. breadth of the engine-room. I remember If this argument be used, I shall not be it burnt the nap off my great coat and so wasteful of your valuable space, even spoiled it. The experiment was repeated if you would permit it, as to attempt its reover and over again." It may be ob- futation; for surely the claim of " safetyserved, that this experiment was tried as ought not to be allowed to an instrument, long since as the year 1816. The in- the protection of which can be destroyed flanımable gas issued from a blower in by that which is ever to be expected, is of the Morton West Pit, one of the Earl of frequent occurrence, and against which Durham's collieries. Sir H. Davy was no human care can guard-viz. the agipresent, and it appears, from Mr. Buddle's. tation of the atmosphere of a coal-mine. account, explained on the spot the dan- If this, sir, were a subject on which indi. ger of exposing the lamp to a current of vidual feeling could with propriety be explosive mixture (fire-damp), as he said expressed, I should thank your correit would risk the passage of the flame spondent, B. D., and yourself, at some, through the gauze.

length, for the opportunity this letter Another recorded and recent instance gives me of making the fact known, that of its failure with fire-damp, attended the Davy-lamp has been found insecure with a fatal result, is described by Mr. -not only with factitious gases, but with George Mitcheson, an extensive mine- the inflammabla air of coal-mines. agent, and one of the witnesses examined

I remain, Sir, before the Committee, who states, p. 190, Your obedient and obliged servant, " that he saw two men go down the Green

GEORGE UPTON, Dock Pit, Staffordshire, with a Davy- London, Sept. 21, 1836. lamp; and that after they had descended, a pail of water was thrown down the shaft, with an idea of increasing the ventilation. That as soon as the water (From the American Railroad Journal.) was thrown, the pit fired, and one of the Sir,- In a late Numher of the Railroad men was killed the survivor, who was Journal, I observe a communication from the sadly burnt, said that as soon as the wind President of the New Orleans and Nashville came, the gas exploded-no other light Railroad Company, in which it is stated that was in the mine at the time." The next engineer H. J. Ranney, Esq., of that road, witness, Mr. William Forrester, agent to

proposes an increase in the width of the the Earl of Granville, states, p. 199,

railway track, viz. 5. feet instead of 4 feet “ I have seen a lamp (a Davy) fire the

8] inches, the width generally adopted, and carburetted hydrogen gas in a thirling.”

requesting the opinion of professional men on

the propriety of the change. It has long I shall conclude this part of the subject appeared to me that our engineers were laby a reference to a trial of the Davy- bouring under a mistake, in restricting the lamp, also with the actual inflammable width of track upon our railroads to 4 feet. air evolved from coal, described in a cer- My reasons for this belief, I will briefly state tificate presented by Mr. Roberts to the as follows: Commitee on his examination, and pub- 1st. By increasing the width of track, the lished by thein, p. 260. It states i On

maximum speed for safe travelling may be the inflammable air being brought to act

increased. This is owing to the fact, that on the Davy-lamp, the flame passed

with wheels of a given size, the breadth of through the wire-gauze and ignited the

base compared with the height or elevation

of the centre of gravity of the load is ingas outside.” This experiment took place

creased—the carriage, when under an equal in Parks's colliery, near Dudley, March,

motion, possesses therefore greater stability, 1834. The infainmable was taken from

and will bear a greater speed without ina sumpt in the colliery, and its explosion creasing the danger of " flying the track." witnessed by M, Parks and seventeen Rod. The diameter of the wheels may be

BEST WIDTH OF RAILROAD TRACKS.

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forming the road-bed and the superitfucture

444 ARSSRS. BOWARD'S AND SYMINGTON'S SYSTEMS OF CONDENSATION. the carriage possess need

or 5 lbs. for each ton weight, en ibility, and under the same rate

over and above the engine would make fewer strokes The level rüadon. Assuming that the increased to advantage of this is evident. : In Bigha mo. sistance is ta proposition to the sliding of the tions, it would result iorassating of power! labels, wluicts is probably

as great antallows The movement ofqthe piston being slowen, ancep rase the circumstances tjof the caso, rik the expansive forejo (the stene would have warrant board wę podoba, resistance Puig grgate effecte iThere would be less friction, mented in consequence of widening the track Jessi wear and tear of the parts of the

engine, 10.03Seet ypon, the fame, curte. Oply 12 or more steadiness of motion, and

a less frequent
'14 ounces

and if esti: oceasions for packing the piston-plate, and

mated for the repairing and lightening the joints.

portions of cayen Juryature of the curved

railrbaas, 7w1t be found 3rd. The narrowness of the tracks upon not to`exceed one of two our railroads, has been the cause of heat

weight, an amount too

weber con

put in inconvenience in the construction of engines, competition with the important advantages the space being insufficient for the requisite to be derived from the greater widths size and proper arrangement of its parts. $ 2nd. Ang:her objection is the increased This is a consideration of great importance length which must be given in the turns-out. in a practical puint of view, and is entitled This again is an item, 10. minor, inuortance, to great weight.

the addition to the length, 904 exceeding jp 4th. By increasing the width of the track, each case more than on

10 stele the motion of the carriages will not be as 3rd. By widening, the track. cost of much affected by any slight depression or irregularity in the rails. This is likewise a

bed consideration of importance, particularly in 26 feet wide; an ordinary width, thise pense a country where, from the powerful action of need not be inereased for the wider track of the frost, it is so difficult to preserve a level 54 feet more than the fortieth or fiftiethy part and even surface to the road. The irregu- oir the average, and

as it regards the speclarities which may exist in the surface, will structure, the additional expense is simply be less liable to be increased by the working the cost of adding 9 inches to the cross-ties, and pitching motion of the engine and cars, if there are any, which, if they are of wood and as the motion will be less unsteady, more or iron, will not much exceed 100 dollars per uniform and regular, a favourable effect will mile for a single track, be experienced, in contributing somewhat to the efficiency of the motive-power.

Jeserving of notice they are the

4th. The remaining objections ately 5th. Adding to the width of the track, of carriages, and the cost of 19 inches addisecures a more equal bearing of the load upon tional width of ground. These, like the preeach wheel, and upon the rails—the carriages ceding I have noticed, can bave but are rendered more commodious for passengers, and better adapted for the conveyance of with the very great and important auranvarious kinds of freight, and are in all re- tages to be derived from an increased width spcets more safe,--the capacity of the road of track. I am, & SUBATON. -81 10. for business is at the same time increased,

99 is het . more space is allowed for forming the horse

[[ chwiliados 152241910 17 148 les track, and the dust and broken materials MESSRS. HOWARD'S, AND SXMINGTON'S from the track are less liable to be thrown

niSYSTEMS OF CONDENSATLON, bens upon the rails. The above are the principal advantages ;

Sir,+Allow me to request such of your now for the disadvantages.

readers as may be sufficient interest on 1st. By widening the track, the difference the subject of controversy betreden Mr. in curvature between the inner' and outer Symington'aird myself; no plade mycomrails on the curved portion of the track is munication in your 69 1st Number in increased, and as it customary to make juxta-position with slik atsverl in your the wheels fast to the axles, the resistance 6838 Number. T'uraghen to luistecusafrom the sliding of the wbeels, &c., in pass. tion of my having made a false statement ing the curves, will be increased. This is,

"Hot his mijury as to his visits to Rotherundoubtedly, the most serious objection tbat

Millies and to the dovad dle about repreBy increasing from 4 feet 81

sepiing. Wijiy suhe proper quarier".my.inbe inercased the one sixth part and surely it will appear that I have våture in prost roads, is about 400 feet. The Teason to complain of the tone of his resistance on a curve of this radius for a correspondence. level road of the usual width, has been found " I now call upon hini, as in fairness I

cost

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RAILWAŤ CONNÍÚNICATION.

445 sdgiw.go, dag, toledo am entitled to do, to state in your jour, his calculations, and now the number svas nal, without reserve, where and in what 1500 per day, being a further increase of manner my process of condensation has one in four ; and thus it appears that no been practised forty-years ago. I must less than half a million travel by it anobserve, too, that this assertion is no an- nually. Now, the population of Liverswer to the questions I pat toshim tend. pool was 165,000, and that of Manchester ing to place the point patrissue in a 183,000, making a total of 348,000 ; and tangible position ph and T must,

therefore, thus they would see that; out of those again call his attention to them

populations, an intercourse of more than quot 90

Your most obedient servant, half a million took place annually. The rodane 0 29900g Thomas HowĀRDO

time by the fastest coaches was three 7. Tokenhouse-yard, Sept. 20, 1836. 000 tomsorg

hours: the time on the first opening of 24387asYbs 30537001 st dtiw ga31/1990

the railway was, by the fastest trains, one RAILWAY COMMUNICATION.5 hour and a half, now it wes but an (From the Atheneum Report of the Meeting of the

hour and twenty ininutes. The fare of 1,0757 in British Association.)1. *

the coaches was, outside, half-a-guineaAt the late meeting of the British As- what it was inside he could not then resoéiation, at Bristol, Dr. Lardner stated collect : by the railway, the average fare some statistical resálts arising from the was 4s. 6d. In this itistance diminution establishinent of railway cotninunica- of time and expense both combined to tions. The subject to which he would increase the number of passengers ; and call the attention of the Meeting, was one the increase, it should be borne in mind, which, at the present time, was particu. was exactly, fourfuld." The second exlarly interestings but it was not for the ample he should refer to, was the railway purpose of showing now, far railway between Newcastle and Hexham; bespeculations, as such, might become fore the establishment of whick, the profitable, that he should bring thein number of passengers by coach monthly forward he had a higher objeet, which was 1700; it is now by railway 7060, was that of endeavouring to ascertain, being rather more than a four-fold it:and if possible, to establish the general crease. Now, the village of Hexham

was by no means an important place ; on communication vhich they led to. He the contrary, it was so insignificant that was not prepared to lay before them any the wonder was, what could possibly reparticular, results, as to the general quire 7060 persons to go upon the railivay. effects of railways; he should contine Ilis third instance would be the Dublin himself to a few facts which seemed to and Kingstown railway. The city of shadow forth the probability of a statis- Dublin contained 200,000 inhabitants,and tical law in reference to the point to Kingstown, which was distant about six which he had alluded. When the Liver. miles, contained 6000 or 7000. There was pool and Manchester railroad was pro- no manufactures, no trade there: true, jected, it was designed for the transit of there was a harbour, but it was used exgoods only, at the rate of ten miles per clusively by the Post-office packets ; 'ilone hour; but it was unexpectedly found of the commercial vessels-noteven those that treble speed was attainable, and then who might be driven in by stress of passengers became the primary conside- weather-being permitted to discharge ration. Previous to the cstablishinent of their cargoes: consequently no goods the railway, there were 26 coaches be- were carried on this railway. Now, when tween Liverpool and Manchester, and he stated what was the intercourse acthe number of passengers making one tually existing, under these circuntrip was about 400 per day. Immediately stances, it must be admitted that the on the establishment of the railway, that effect exercised upon it by the packels number rose to 12,00; thus, in the very was very insignificant. The intercourse outset, an increase took place in the pro- previously existing, too, it must be borne portion of 3 to 1. The railway had been in mind, was carried on by means of a in operation, he believed, since 1828, and rude vehicle called an Irish car, and in from that period the number of passen.. this manner they were carried at prices gers had gone on increasing, with the varying froin 5d. to 7d., the proximate exception of the period of the cholera, number being about

800 daily. The railwhich might very fairly be omitted in way had been opened about two years,

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than money:

* 446

WIRE-PLATE ENGRAVING and the intercourse was in the ratio of a garded that the mere saving of money. million of persons annually. Now that : Dr. Lardner then proceeded to remark furnished another example of the nume- on the value to new.coinpanies of the ex: rical proportion previously referred to : :perience gained in working the Liverpool for if they took the number of passengers and Manchester railway. The charge before the opening of the railway at 800 for transport of passengers on the Mandaily, it would be found that the propor. - chester railway was 1.84.100ths of a tion of four to one would give 3200, and Id.per mile, the actual cost to the proprie3300 was the average of the present tors about id. per mile: whereas a Birnumber:-- the travelling on the Sunday mingham manufacturer had entered in'oa being 7000, the proportion the other contract, by which the whole of the pasdays less; but the average above given sengers on that line «voald be conveyed at being fully made up. He had thus the cast of one farthing a mile, including shown that the law of increase. was four

every, expense of locomotive power, the fold ; he would now show that it depen- .company merely finding the carriages and ded infinitely more on the saving of time the roari. The same company had also

On the Liverpool and formed à contract for the conveying of Manchester railway the price was less goods at 1d. per ton per mile, the conthan one-half the charge by the coaches ; tractor, as in the former case, defraying but on the Dublin and Kingstown railway every charge for engines, &c. Dr. Lardo the charge of conveyance was absolutely ner then proceeded to show the possibiraised, and, besides that, the railway did lity of attaining so high a rate of speed not reach the latter place by half a inile, as 50 miles per hour, and dwelt at great which occasioned to many an additional length, on the effecis likely to result to charge for carriage-hire to take them

the general commerce of the country. over the remaining ground. On that railway there were ihree classes of trains, and the fares were 1s., 8d., and 6d.; the

WIRE-PLATE ENGRAVING. carriages must filled being those at 8d. ; Sir,--I herewith send you a descripit was quite fair, therefore, to assume tion of a proposed new mode of engrave that, in this instance, three out of every ing, of my invention, to be called wirefour travelling on the railway did so plate engraving; and it will give me merely on the score of the saving of time. great satisfaction if you think it worthy It would he well if they could go back of insertion in your Magazine. and see what were the effects produced The wire-plate engraving is intended on intercourse by the establishment of as a substitute for wood-engraving, on turnpike roads and the introduction of

account of its possessing some advan. coaches ; they would find probably that tages over it, as may appear from the the great increase had been wholly owing following description, which, in order to to the time saved by the improvements make clear, I propose to consider the effected. It was reinarkable, however, matter under two general heads; first, a how much results varied, for he had description of the wire-plate itself, and ascertained that, though inuch improve- secondly, the inode of engraving upon it. ment had of late years been effected in 1. The wire-plate is composed of a the mode of travelling by canals-in number of very fine wires laid parallel certain cases the boats having attained together, and closely packed in a inetal to a speed of 10 miles per hour, equal to fraine. In this state the wires, together that of the c aches, while they carried with the frame, constitute a plate, whose their passengers at a far cheaper rate- two opposite surfaces are composed of yet he did not find that they added much the ends of the wires, as these are preto the intercourse. He alluded more sented ontwards or on each side, of the particularly to the boats on the Kendal plate. The wires may be about a quar er and Preston, and the Edinburgh and of an inch' in length, or from that to half Glasyow canals; and, he asked, could it · an inch, according to circumstances, and be doulited, if railways were suoning are to be of the finest steel or brass wire parallel with them, that an increased that can be procured; so fine, indeed, as traffic would immediately take place? that their diameters must not exceed He mentioned this merely to show how 150, or eveu 200, to the linear inch; much more economy of time was re- though if their diameter exceeded that

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