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INSTRUMENT FOR DRAWING ELLIPSES AND OVALS.

his Bude Light; and we must confess that we are not a little surprised at the omission. We believe its merits have been greatly overrated; but be this as it may, considering that it has engaged so much of parliamentary and public attention, and has been preferred before all

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others for lighting the Hall of the Collective Wisdom of the country, these facts ought to have sufficed to procure for it a prominent place in works professing to give a complete history of gaslighting in all its more important practical applications.

INSTRUMENT FOR DRAWING ELLIPSES AND OVALS.

Sir,-Having contrived an instrument for drawing regular ellipses and ovals, or egg shapes, which I find answers the purpose extremely well, I send you a drawing and description of it, in the hope you may deem it worthy of a place in your Magazine.

Your correspondent, "H. P.," would

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oblige by giving his opinion as to the nature of the curves traced by this instrument, which I believe will be found very useful, as it is quickly set and very easily used.

I am, Sir, yours respectfully,

SAMUEL MILBOURNE.

Charles-street, Middlesex Hospital, London.

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Fig. 2.

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Description.

A is a round bar of steel, 12 inches long by inch thick, having a flat bar B, brazed on it send r, and bent twice at right angles, so that its feet n and o may rest on the drawing paper. To the centre of B the revolving bar C is so riveted as to allow the nut p to pass under B without touching. The cylindrical piece D is riveted so as to turn freely in the end of the tracing bar E, its upper end being shouldered and tapped, so that it can be fixed to any part of C by means of the nut p. F is a piece of brass tube, which slides freely on the bar A. To F is brazed the arm M,

which carries one end of the tracing bar E always in a straight line parallel with the bar A; and the other end of E being carried in a circular path by the bar C, all points along the middle of E between D and the screw d, will move in an eliptic path; the situation of D on the bar C determining the length of the major axis, and the situation of the pencil on E determining the minor axis of the ellipse. Thus, the major and minor axes of an ellipse may be varied in any degree by varying the positions of D aud C, and of the tracer on E. If egg-shapes are required, take out the screw d, and slide the tube F anywhere to the left on the bar A, and fix it there by the screw k;

then put the screw d through the groove in the bar E (instead of through the hole on its end as before,) and into the tapped end of M again.

The figures now traced by the pencil will be egg-shapes, whose major and minor axes, and the relative proportions of their broad and narrow ends may be varied in any degree by varying the positions of D and C, of the tracer on E, and of the tube F on the bar A.

G is the tracer holder (shown separately in fig. 2; a detached view of the cylindrical piece D is also given in fig. 3.). L is a screw for raising the bar A off the paper to allow the tube F to slide freely on A. The horizontal length from the angle h, to the centre of the rivet v, must be equal to the length of M between the centre of the screw d, and the axis of the bar A.

DR. NORMANDY'S SOAP PROCESS. Sir,-My attention having been called to a paragraph concerning a patent of mine, published in your Magazine of the 30th ultimo, page 343, signed "A Shaver," I have perused it carefully. Coming, however, as it does, from one who avows that "he is not much of a chemist, and certainly never was a manufacturer of soap," I might have allowed it to pass unnoticed, were it not probable that by so doing the public, who read your Magazine, might be prejudiced against my plan, and assume that this "Shaver's" opinion and statements are correct, because they had not been contradicted.

The conclusion which the "Shaver" arrives at, namely, "that it does not require a great deal of chemical knowledge or of manufacturing practice to see that these alleged improvements are altogether fallacious," betrays at once a presumption and an injustice which might well lead me to impute sinister intentions to the writer; I am, however, willing to believe that ignorance alone may be the

cause.

If "A Shaver" had tried the only fair test left open to him, lacking both chemical and practical knowledge, and used the soap, methinks he would not have been so ready to condemn it. For his information, however, allow me to say, that both chemically and physically my method is a decided improvement upon

the ordinary plan, not a " useless addition," as he is pleased to call it; and I have yet to learn that a mode of making a better article from cheaper materials is a fraud. If (even at the same price as others) I offer the public a better soap, that is, a soap possessing greater durability in water, increased cleansing properties, a soap that will retain its full weight, instead of losing ten or twelve per cent., as all other soaps do by keeping, it seems to me that I confer a benefit, not practise a fraud.

I could easily prove, chemically, that the union of the salts of soda and of potash with soap, as described in my process, gives it a great advantage over other soaps, and answers a purpose of saving and economy both to the manufacturer and to the purchaser, to an amount not to be attained by any other means at present known; but as "a Shaver in business" (that is, I presume, a barber) knows little of chemistry, and nothing of soap-making, let him try it on his customers' chins; or if, deficient also in shaving skill, they, knowing it, will not permit him, let him perform the experiment on his own, and then he may, perhaps, favour us with an account of the result.

In the mean time I remain, Sir,
Yours very respectfuly,

A. L. M. DE NORMANDY, M.D.
Soap Factory, 11, Gloucester-terrace,
New Road, Whitechapel, May 12, 1842.

ABOLITION OF THE CLIMBING-BOY SYSTEM-HINTS ON CLEANING CHIMNEYS

BY MACHINERY.

Sir,-As the new Act respecting the sweeping of chimneys will so shortly be in operation, it is time that all persons turn their attention to making such new arrangements in their flues, where it may be required, as will enable them to be cleaned by machinery.

In considering this subject, it has occurred to me that a new mode of cleaning chimneys might be adopted, that would prevent the necessity of any alterations; but I speak with diffidence on an untried subject: I will, however, venture to throw out the hint in your valuable Journal; and in time, perhaps, it may be ripened into use.

Most flues have from a square foot to a foot and a half of area in their cross

THE PARIS RAILWAY ACCIDENT.

section; and if 60 feet high, will contain a body of air of from 60 to 90 cubical feet. I propose, by a very well known process, to give this body of air, from below, the velocity of our greatest tempests, which are found sometimes competent to remove the chimney, much more the soot.

Air, at 100 feet per second, exercises a force of 25lbs. on the square foot; and would, therefore, if not found sufficient to clear away soot alone, readily force such elastic whalebone brushes, or other matters, through the flue as may be found necessary to loosen it from the bricks, when it will be blown out.

It would be a nuisance to blow the soot out of the top of a chimney in towns; hence, in this case, the top of the chimney should be fitted with a large bag reservoir, that will contain more cubic feet of air than the chimney, and the blast must be stopped when this is filled. The soot must be left to settle for a few seconds; the air let out at a flap valve, like that of an organ bellows, and the operation repeated as often as required. A spherical bag, ten feet in diameter, will contain above 500 square feet.

A sort of parasol, made of strong canvass and cane, may be used for driving the brushes; and these may have a few light wooden wheels to guide them where flues bend much.

A man can exert the ordinary force of two horses for a few seconds; and by so constructing the ordinary centrifugal bellows that several men can apply their strength readily to it, it appears that the velocity of 100 feet per second can be commanded by multiplying wheels in the usual way.

It will be necessary to have the front openings to the chimney well secured by an expanding frame and strong air-tight cloth, and also any others that communicate with it.

I am, Sir, yours, &c.

G. C.

THE PARIS RAILWAY ACCIDENT- MORE

VICTIMS TO MISMANAGEMENT.

The Paris and Versailles Railway has been the scene of one of the most tragical disasters which has yet occurred in the history of railways. Two fourwheeled engines were drawing, at a great

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velocity, a train of eighteen passenger carriages—the axletree of the first broke, and down it fell-the second ran over the first and crushed it to pieces—the second was in its turn run over by three of the carriages immediately behind it, each rising over the other-and in an instant engines, drivers, carriages, passengers, were all mingled together in one horrid heap of destruction. An instant more, and the heap was on fire from the burning coals scattered by the engine furnaces! Of those who escaped immediate death, all who were so maimed as to be unable to move, only survived for a few minutes to perish more awfully by the flames. And still more sad to say, there were in all probability not a few left, with limbs unbroken, and with strength sufficient (if strength would have sufficed) to save themselves, but who were prevented from escaping by the practice of making fast the doors of railway carriages-literally tied to the stake, in fact, and burnt there to ashes, martyrs at once to railway mismanagement and railway discipline.

The number of the sufferers by this awful calamity has not yet been accurately ascertained. According to some estimates not fewer than one hundred persons were killed, and some sixty or seventy wounded, (including those in the carriages in the rear who suffered from the severe shock given to the entire train); according to others the loss of life was considerably less-according to all it was enormous.

The Academy of Sciences immediately held a meeting to enquire into the accídent, when a Report upon it was read by MM. Combes and Senarmont, engineers, which assigns it to the following causes :

"The accident is due to a fatal concurrence of circumstances, which are all so many gross faults, easy to have been foreseen, and still more easy to have been avoided, so that the future prosperity of railroad companies is by no means compromised by this sad affair.

"The first cause of the accident was the employment of a locomotive with four wheels. It is essential that every carriage intended for service on a railroad, should rest on six wheels at least, in order that if one of the axles should break, the carriage

should still rest on supporters, and continue its course.

“The second fault consists in the employ. ment of two locomotives for a single train. The consequences of this arrangement are self-evident.

"A third circumstance is the precaution taken to lock the doors of the wagons, so that in such a case as that which occurred all escape was prevented, and the travellers were condemned to suffer all the consequences of the first accident.

"A fourth cause which had much influence on the catastrophe, was the neglect to isolate the train from the locomotive, so as to prevent the shock occasioned by the sudden check to the speed with which they were proceeding.

"It is worthy of remark, that if all those causes had not existed together, and if only a single precaution had been taken, the accident would not have happened. If the first engine had been furnished with six wheels when its axle broke, it would not have lost its equilibrium. If a second locomotive had not been employed, the only consequence of the accident would have been a shock; and even admitting that the two first causes of the accident existed, had the doors of the wagons not been locked, a number of the passengers might have escaped the flames. In fine, the interposition of the buffer system would have saved the train, even if no other precaution had been observed."

It will be in the recollection of the readers of our journal, that the danger to be apprehended from each of these causes, with the exception of the third, has been repeatedly pointed out in its pages, (as well as in those of several of our English contemporaries;) so that it is not merely want of foresight, as the authors of this Report represent, which we have on the present occasion to lament, but a culpable persistance in practices which the voice of science has long since condemned. The French engineers, it is true, have still the authority of English example to plead in extenuation, for the same practices which have led to this disaster on the Paris and Versailles Railway, prevail on some of the

most important of our own railways; but there is also much good English example to the contrary-on the four wheel point, at least, if not on others. It would be well, however, for humanity, if the engineers of both countries would heed example or fashion less, and take counsel of common sense and experience more. No authority, however long standing or eminent, can excuse adherence to such palpable blunders in mechanical construction and disposition, as the preference of four wheels to six, the employment of two engines to draw one train, and the attaching of the passenger carriages immediately to the engines, without any buffing apparatus or other means of protection between. (We say nothing at present of the locking of the doors, for that is a point on which there is much, we apprehend, to be said on both sides.) Neither ought any past exemption from accident-even though it were twice as great as the managers of our London and Birmingham line boast of as their excuse for doing nothing-to be urged as a reason for delaying one hour the rectification of these blunders. The accident which has just filled all Paris with consternation and sorrow, may be repeated on some of our own lines to-morrow. There is nothing whatever in their arrangements to prevent it; nɔthing to make breaking of axles, and engines running foul of one another, and upsetting of fire-boxes, less likely to happen, or happening, less likely to produce extensively fatal consequences, on the one side of the Channel than on the other.

We should not wonder, if notwithstanding all that has passed and all that has been said, the adoption of a more improved system of railway transit were still to have considerable opposition to encounter-at the hands especially of those who have set themselves up as the pen and ink champions of things as they are (for what so obstinate as the vanity of a little learning?)-but we shall wonder greatly if the good sense of society bear much longer with the apathy of railway proprietors, or the empty babble of their apologists. It is high time

The most inveterate scribbler of them all is a pestilent ironmonger, who on the same principle that the poker and tongs may be supposed to know something of the chemical principles of combustion, because their station is near the fire-place, ima

THE PARIS RAILWAY ACCIDENT.

to be done with prating about the safety of existing practices, when people are smashed to death by them in scores and hundreds.

We conclude by earnestly inviting the attention of our readers to the very sensible and impressive letter which follows, on the subject, from Sir George Cayley, to whom the public are already indebted for a very able Essay on the prevention of Railway Accidents, as well as many valuable practical suggestions for the purpose, and whose opinions have the recommendation of being not only those of a gentleman of well deserved eminence in the scientific world, but of one whose rank in society gives assurance of their being promulgated solely with a view to the public good.

SIR

ON THE LATE ACCIDENT ON THE PARIS AND VERSAILLES RAILWAY.-BY GEORGE CAYLEY, RART. SIR, It is obvious that if some more efficient precautions respecting railway conveyance than those at present in use be not adopted, we shall be subject occasionally to such sweeping and horrible catastrophes as have occurred near Paris, in which, at one fell swoop, from 80 to 100 persons have been killed under circumstances too shocking to dwell upon; for of those who witnessed the miserable reality, several have been deprived of reason. But although we may choose to avoid allowing our imaginations to particularize these horrors; yet it will not permit us to draw a veil over the broad fact that when we travel per railway, we place ourselves within the range of a similar result. This state of things has a twofold evil attending it; nervous and timid persons are absolutely prevented from using this mode of conveyance; and

gines that he must know better than any body else how railways and railway carriages should be constructed, because his daily business is with iron bars, hoops, and faggots. It was this mischievous busy-body who either moved or seconded (we forget which) the memorable resolution of the Birmingham Railway Conference, (the Masters' Conference, we mean,) that none of the accidents which have occurred on railways, were in the slightest degree imputable to want of judgment or care on the part of Railway Directors! One of this gentleman's most recent exhibitions of ignorance was amusing. Not knowing the difference between ascension and accension, he mistook the one for the other, and wasted a ream of good foolscap in proving that a bubble of gas may mount into the air without being set fire to. If Master Shallow do not shift his quarters soon, the Thames will be in danger.

or

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the great mass who venture upon it, travel under a painful sense of the danger they incur. It is impossible perfectly to exclude all risk from this or any other mode of conveyance; but it is equally absurd and wicked not to have the most rational means of preventing these accidents enforced upon the railway companies by law. Other modes of conveyance are nearly put down, and very soon none of her Majesty's liege subjects will be left any choice in their means of conveyance; and the question is, whether their lives are to be thus continued in jeopardy (when ready means are at hand to prevent it, or at least to reduce it within the ordinary chances of life and limb,) or that companies monopolizing the means of conveyance, are to be put to a reasonable expense in being compelled to adopt such means, as will prevent nine-tenths ninety-nine-hundredths of these horrors? If Government be not permitted to interfere with private property, vested in these companies, for the purpose of protecting life, and that property is thus made to outweigh the value of life, it is full time that this noble invention should be taken entirely into the hands of the Government, and thus ripened into safety, clear from the mammon of money-making. To avoid expense, the companies are obliged to fence themselves round with every barrier to prevent the introduction of those improvements, which experience or invention has suggested; but it is in vain for these parties seriously to pretend that all these matters are visionary schemes and below their practical notice, though very possibly many may be so. I will put the case thus. It has been suggested over and over again, by many persons, and in various ways, that besides the usual buffers to each carriage, some general system of elastic matters should to a great extent intervene between the head of the train and any obstacle it may meet to stop its course; nothing can, to common practical sense, be more obvious than this; yet nothing has been done by railroad companies respecting such an arrangement which, in fact, would cure nine-tenths of the head and front of the offending.

However, this would not alone meet every case; let us take, for instance, that which has just occurred near Paris. Had some general system of buffers intervened between the engines and the head of the train of waggons, the accident would, it is

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