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THE BROKEN AXLE EXPERIMENT.
on an engine thoroughly out of repair, with was led, in consequence, to inspect the ena divided axle reduced three-eighths of an gine very minutely. inch in length, and more likely, therefore, to The engine No. 18 is mounted on four slip off the rails, may be considered to have wheels ; diameter of the driving wheels 5 feet established the important fact that the com 6 inches ; that of the others (or fore-wheels) pany's engines are not liable to fall down 4 feet; the framings and bearings are inside because a fore-axle may by possibility break. the wheels. I found the fore-axle cut through
The circumstances connected with the about 3 inches inside the bearings of the experiment are not likely to occur in ordi near wheel; the longer section of the axle nary practice, for the following reasons : had dropped about half an inch below the 1st. The engine was in a state to require
shorter one. As I had expected that the that it should be taken off the road.
bearing was sufficiently broad to retain the 2nd. The fore-axle was below our standard axle in its truly horizontal position, even size. And,
when cut through, I made particular in3rd. It was cut in two in the place most quiries as to the state of the brasses, and likely to cripple the engine if a fracture were was informed that they were much worn; in to happen, but not where it would probably fact, the engine had been sent into the shops take place.
for the express purpose of having them re. In conclusion I have to observe, that from newed, but that it had been determined to July, 1837, when the line was opened, to try the experiment before the execution of the present period, there has not been a
any repairs. single instance of an accident to our fore. After satisfying myself on these points, I axles; that where crank axles have broken, went to Pinner Park gate, to inspect the pothe engine has invariably been driven on its sition of a proposed new station ; whilst own wheels to Wolverton for repair, and in there No. 18 came up, with a train of six most instances has taken its train to a sta loaded goods' waggons. I got on the ention; and I may add, that of the few cases of gine, and when we had proceeiled about six fractured cranked axles two only have oc miles, we ran off the road ; the speed at the curred to passenger engines.
time was from 15 to 20 miles an hour. The Thus the following important facts may engine weat about 200 yards before it was be regarded as established :
brought to a stand, striking, in its passage, First-That of the engines in use on the against the chairs and sleepers with great London and Birmingham Railway the fore. violence. It was evident from the motion axles have never been broken.
that for some considerable portion of this Second-That when experimentally broken distance, the engine was fairly forced forunder the most unfavourable circumstances, ward by the momentum of the train behind, the engine was not disabled. And,
none of the waggons of which, or the tender, Third--that in the only two cases where having followed the engine off the road. the crank axles of passenger engines have On examining the engine after the acci. been broken the engines were not disabled. dent, there was no appearance of any deI am, dear Sir, yours, faithfully,
rangement of the machinery; the tires of the (Signed) EDWARD BURY. wheels were deeply indented by coming in
contact with the chairs. To E. Bury, Esq.
The engine maintained her vertical posiLondon and Birmingham Railway, tion, was replaced upon the rails in about 20
Camden Town, May 30, 1842. minutes, and proceeded to her destination. My Dear Sir, -I was at Wolverton on Whilst upon the journey, I did not notice Tuesday the 24th instant, and saw engine any unusual motion; and had I not seen No. 18 preparing to start on an experimental that the fore-axle was severed, I should not trip to Camden station.
have been aware of the fact. Mr. Parker, foreman of the shops, in On the whole, I consider the experiment formed me, that by your directions the fore as highly satisfactory, for although I did not axle of the engine had been cut through, for expect that the engine would have gone off the purpose of ascertaining, 1st, whether the the road, yet her having done so was a much engine would, in that state, keep the road; more satisfactory test of its safety as a pas. and 2nd, in case the engine did get off, whe senger engine, than could otherwise have ther it would roll over, or retain its vertical been attained. position.
Had there been anything in the construcAlthough I had myself no doubt as to the tion which would render it liable to upset, I results of the experiment, yet being aware feel persuaded that the violent action of the that they would, in all probability, have an train against the foot-board must have proimportant effect in establishing or condemn duced that result. And as this point could ing the use of engines of this construction, I never have been determined until an engine
with a broken axle had run off the rails, the The English sailor who made a sumexperiment was so far conclusive.
merset from the mast-head and did not I believe that if the brasses had been in
break his skull, bade the envious Dutchgood order, or if the axle had been cut away men “do the like if they could."_And at the back of both the wheels, and removed even so it is with Mr. Bury's Man Friday altogether, the engine would not have gone
-having miraculously survived his ride off the road; for the tendency of the longer
in the broken axle carriage, he bids all section of the axle was to throw the wheel heavy a-xled engineers learn wisdom from to which it was attached out of its vertical position, and to bring the flanch in close and
his example, and bother themselves with continuous contact with the rail, thus greatly
axles no more! increasing the probabilities of the wheel
The wonderful success of these wonmounting the rail on meeting with any ob
derful experiments may furnish a useful struction, however small.
hint to others besides railway engineers. I am, &c. &c.
When that respectable and enterprising (Signed) Robert B. DockRAY. class of mariners yclept "free traders
are hard pressed-running before the We said last week that “the next thing wind with every sail sel-it is a common of course would be to dispense with practice with them to knock away the axles altogether.” We have been ac wedge-pins from the masts, in order that cused of levity in so speaking, but our they may have freer play, and if that readers will see that the Man Friday" does not suffice, then to saw through a who here backs his master in such capital number of the timber heads (it would style, is, with all the earnestness in the almost seem from this as if Mr. Bury world, quite of our opinion. The only had stolen a leaf out of their loy). But accident which happened to the car by the same rule that an axle cut through riage with its broken axle was the run is as good as a whole one, and no axle at ning off the rails, and “Man Friday" all better than either, it follows that the says, “I believe if the brasses had been surest way to escape would be to cut in good order, or if the axle had been cut away the masts by the board, and remove away at the back of both the wheels, and the timber heads “altogether.” If this removed altogether, the engine would be not good, sound, practical reasoning, not have gone off the road.” The ex it will at all events do to “tell to the periment, therefore, was faultless in allomarines.” but the single particular of the axle not The running off the rails was an gly being "removed altogether." *Had it incident to be sure; bad it been on a high been only removed altogether, there embankment, or in a deep tunnel for exwould have been no running off the rail ample, it would have knocked the Man -no axle, no accident!
Friday into Saturday at least. But Friday How idle then to entertain any fear of shows clearly enough that it was all breaking axles! All who are troubled owing to his master’s grand and original with such fears have only to break them ideas on the subject not being carried out before starting, or still better, have none to their full extent. Had the axle been to break. The jester's well-known re “ removed altogether,"nothing of this unmedy for burglary is nothing to this. toward sort would have occurred. The “Leave your doors open," quoth the danger to be apprehended is not so much jester. * Have none at all," is the from breaking axles as from not breaking maxim of our modern jester, “Robert them enough. Broken into two pieces B. Dockray."
they are admitted to be a little dangerous, Logicians allow that there is such a but broken into a million, they exhibit thing as proving too much, and common the very perfection of safely. Mr. Bury's sense people intend something to the beau-ideal of an axle is an axle of saw. same effect when they say that "you may dust! have too much of a good thing;” but at Worthy of all admiration is the bold railway head-quarters there is something manner in which Mr. Bury has, in this a vast deal better than either logic or particular, made head against the vulgar common sense—there is that “stubborn outcry. Some persons, of the weak stuff thing" called “fact," which “dings a' ” of which ordinary men are made, would and may not be despised." No axles have assented to the danger to be appreand no accidents against all the logic and hended from the breaking of axles, and common sense in the world!
BLAXLAND'S PROPELLER AND CAMBRIAN STEAM-ENGINE. 487 have sought to soothe the public mind by the ingenious Mr. Jones, of Smethwick, and much talk of providing against it. Not so which you have yourself in your Notices to Mr. Bury ; be stoutly denies the danger Correspondents of the 28th May last, been 6• altogether,” and at the risk merely of pleased to characterize as one of the best making mincemeat of his Man Friday,
which has yet come out.” and another helper or two, he proves to
From the manner in which the postscript you, beyond the possibility of dispute,
account of the experiment with Mr. Blaxthat all your fears are vain.
land's little Jane on the river Lea is given So, long life to the bold Mr. Bury!
at the close of your report of the trial on And long may his four-wheeled Jug
board of the Swiftsure in the Mechanics'
Magazine of the 4th inst., I infer that gernaut manufactory endure and flourish.*
though present at the latter, you were not
so at the former; and this inference ex. BLAXLAND'S PROPELLER AND THE
cludes a suspicion which I might otherwise BRIAN (JONES's) STEAM-ENGINE.
have been disposed to entertain of your imSir,-I quite agree with you as to the
partiality. For by another account of the propriety and fairness of considering Mr.
river Lea experiment which I have before Blaxland's propeller, and his mode of con
me, (that of the Hertford and Bedford Reveying the power of the engine to it by former of May 28,) I find that the applicastraps and bands, instead of toothed wheels,
bility of the Cambrian engine to canal and as part and parcel of one invention ; neither
river navigation, from the direct nature of am I disposed to question the correctness of
its action, was brought almost as promi. the judgment you have pronounced as to
ne under the notice of the gentlemen their united capabilities. But I must beg
present as the merits of the Blaxland proleave, as one of the public (merely), to put
peller itself-though your notice is perfectly this case: suppose a simple and efficient
silent on this point. The Hertford Remode were discovered of conveying the former's account mentions, among those power direct to the propeller, without the
who were present on the occasion, “Mr. intervention of either bands or toothed
Crosley, the patentee of the new Cambrian wheels, would it be right that the public
engint,'' (one of the proprietors of the pashould be excluded from the adoption of
tent, would have been the more correct dethat mode because of the duality of Mr.
signation,) and it quotes Mr. Crosley as Blaxland's patent? Must we either make
giving the following account of the engine: use of Mr. Blaxland's propeller in conjunc "The patent engines suitable for barges of 50 to tion with his peculiar gearing, or not use it
60 tons, should be of about six-horse power, either all ? of this be really the case, then I can
of high pressure, or high pressire expansire and con
densing, about the same space being required for only say it is a great pity-a pity on Mr. either, namely, 3 feet in lenzth, 18 inches breadth, Blaxland's account, and also, perhaps, a
and 2 feet in height--the weiht, about 12 to 15
CWIS., without boiler, wirich would also be of small pity on account of the public; for certain it
size, calculating the weight altogether at about lg is that there are engines—though, to be ton. The consumption of fuel is less than that resure, the invention of yesterday only--which quired for engines of the same denomination of the will convey the power direct to the pro
usual construction; and a still less consumption, if
engines of high presure, expansive and condenspeller without the intervention of any sort ing, were employed. The cost of the latter would of gearing whatever, and equally certain be about a half more. But the great advantage that if we may not use these engines in
possessed by our engine is, that it can be connected
direct, and without geariny or intermediale motions, connexion with Mr. Blaxland's propeller,
to the shost of the propeller, the speed of which will we shall be obliged to have recourse to some b! the su me as that of the stian engine, which is vaother propeller, though possibly not by any
riable at plea-ure." means so good.
The words of this extract, which I have In these remarks, Sir, I have particularly marked in italics, may perhaps serve to exin my eye the Cambrian engine, invented by plain why all about the Cambrian engine,
and its direct action, was so studiously We have seen a business circular of Mr. Bury's
omilted in the account with which you were respectable firm which shows that, after all, he and they have a shrewd suspicion that the days of the four
furnished of the river Lea experiment. wheelers are numbered. After stating what they con However, it is not by such small masider to be the advantages of the four-wheeled en
noeuvres as this that the merits of the Camgines, they wind up with these remarkable words, *In justice to ourselves we have thought it right to
brian engine are to be kept in the shade. lay these remarks before the public, at the same time
Since the river Lea experiment, a deputathat we are quite ready to construct engines upon tion from the body of canal proprietors has sir, or any other number of whcels, freeing ourselves from the responsibility of the consequence of any
paid a special visit to Mr. Jones's factory at other plan than our own, and only requesting that Smethwick, to inspect some engines which such of our friends and the public as may entrust he has completed on his plan, and from the their orders to us, will permit us at least, for the
satisfaction they expressed with them, there safety of travellers and our own credit, to adhere to inside framing. BURY, CURTIS, AND KENNEDY."
is little doubt of their soon having a trial on
some of our principal canals—with or with periment, and were not aware of the omis. out the Blaxland propeller, as the case may sions of which he complains. We have a be.
I am, Sir, yours, &c., S. description of the Cambrian engine in hand, [Our correspondent is right in supposing and hope to be able to give it next week.that we were not present at the river Lea ex En. M. M.]
TIIE VOREST OF DEAN COAL AND IRON MINES,
MINES-AWARD OF THE COMMISSION-
the central opening, I believe the follow THE FOREST OF DEAN COAL AND IRON ing description may also be acceptable to many of your readers.
Fig. 1 is a vertical section, and fig. 2 The Forest of Dean comprehends an a horizontal section of the central parts. irregular area of about thirty miles in The division pieces d a, da, da, da, which circuit, lying between the rivers Severn form the four arms, or water-spaces, do and Wye; covered for the most part with not run inwards so far as the central
timber, in various stages of growth; and opening, but they terminate in sharp famous for its mines of coal and iron. ends at a a a a; and the whole of the
From time immemorial, all male
persons space bbb b, which is inside of the inner
born in the hundred of St. Briavels, in ends of the division pieces is so propor which the Forest is included, have enjoytioned, that the speed of the water passing ed the right of working these mines, subthrough it will be uniform, or nearly so, ject only to the leave or licence of the at each point of its passage, for the pur- gaveller, or deputy gaveller of the Forest pose of allowing the water to enter the
being first obtained, and to the payment arms without any shock, when the ma of an annual galeage rent, or duty to the chine is in motion. This is a very ex Crown. In default of, or in lieu of cellent plan where there is always a suf such payment, the Crown was entitled to ficiency of water to supply the whole of put in a fifth man for a share with other the arms; but when a machine is made
four men (free miners), after the coal or for a situation, where occasionally there iron had been won by means of a shaft is water not for the whole of the arms
or level, in the working of which the but sometimes only for three, two, or one Crown's fifth man was not required to arm, Mr. W. proposes to put plates, assist. In ancient times the practices of curved in the manner shown by the lines the free miners, as regards the opening marked ccc, in fig. 2, into the space and working of mines, and the carrying bbbb, (see also fig. 1,) and thus each of coal or iron ore, were regulated by a space betwixt a pair of plates will con court or jury of free miners, who met at duct the water into an arm. When the what was appropriately called The Speech space, b b b b has certain dimensions, it House, in the centre of the Forest, and may be found necessary to skew or twist adjudicated on all such matters. Some "the plates c c c, in order to allow the records of this Court of Free Miners, water to enter the machine when in extending over a period of eighty-six motion, without interruption. These
years, from 1688 to 1754, are still preplates may require to be twisted from served in the office of Woods and Forests; other causes.
The smaller dotted circle but from these records it appears that the shown in fig. 2, gives the size of the Court was never at any time adequate to central opening; and the inner ends of the purposes of its institution, and eventhe arms, when the plates marked ccc tually it became extinct. For more than are not used, terminate at the large dotted half a century afterwards the free miners circle, in the same figure. The plates, appear to have done very much as they marked cc c may not run inwards so far pleased amongst themselves; for though as the centre of the machine, and their the old customs were always referred to, inner ends may run from the edge of the as furnishing the rules by which the agents central opening upwards and towards of the Crown and the free miners were the centre; or the innermost points of to be guided, yet these customs had conthese plates may meet at e. At and near stantly to be modified to suit new cirto the central opening, the water may be cumstances, and were wholly inapplicaallowed to flow somewhat quicker than it ble to the deep coal mines worked by the does at the other points of its passage aid of modern machinery. The perthrough the space b b b b, to allow for plexity of this state of things was much the change of its motion from the perpendicular to the horizontal direction, and for other causes.
• The Award of the Dean Forest Mining Com
missioners, (under the 1 and 2 Vict. c. 43,) as to the I am, Sir, yours, &c.
Coal and Iron Mines in her Majesty's Forest of J. C. Dean, and the Rules and Regulations for working
the same, &c. By Thomas Sopwith, F.G.S., the Glasgow, May 27, 1942.
Commissioner appointed on behalf of the Crown.