become equal to nothing, and this because the NOTES ON RECENT SCIENTIFIC DIS- in its transmission to the points of support is No New Metal-Preparation of Oxygen- brown coal the author found to be soluble in water to some extent (bituminous coal he also states is soluble to a slight extent), and the matter dissolved from the surface, being retained by interior absorption, goes to augment still further the compactness of the seam, while the surface absorption builds up the seam to greater thickness. In this case, he adds, we require no miraculous interposition of pressure to remove the vesicularity which decomposition entails in the indurated mass, and the theory of surface absorption reduces the difficulty we have in accounting for the remarkable thickness which has been attained outline of Mr. Skey's theory, founded upon by certain coal seams. We give this bare experiments which look satisfactory, and leave a plate girder is exposed; and in order to see but added a doubt as to the reality of the dis-him to the geologists. We advert, howthe effect of the loading forces in their trans-covery. The authors have recently confessed ever, to one other point which may have mission through the girder, let us suppose that their mistake. They were analysing a speci- some practical interest to gas manufacturers. we begin at one of the points of support, and men of phosphorite that contained a trace of The author was at a loss to account for the further, that the last bar in the frame work of copper, and the blue line in the spectrum, large amount of sulphur he obtained from the girder is supposed to slope away from the which they believed to indicate the presence coals containing only traces of pyrites and support towards the centre of the girder, into of a hitherto undiscovered metal, was occasulphates. Actual experiment showed him the direction of whose length it makes a sioned by chloride of copper. Sic transit! that the coal had absorbed a considerable certain angle. Now here, as in the case of the The preparation of oxygen from a mixture amount of sulphuretted hydrogen, which was beams, we have a force acting vertically of chlorate of potash and binoxide of manga- evolved on heating the coal to 212 deg. or upwards, viz., the supporting force at that end nese is so easy and convenient that it would 300 deg. Fah., a temperature which precludes of the girder; but, instead of this force being be foolish to resort to any other process with the idea of any reduction of the sulphide or transmitted through the girder in a vertical these agents at hand. direction, we see that now, in order to support the load, it must be transmitted through the bar mentioned previously. Now as this bar is kept in position at its upper end by a bolt or rivets and another bar of equal length and of equal slope but in a different direction from the first bar, and as these bars are so fixed that they constitute a rigid triangle, we know from the principles of stress in such a triangular frame that the stress in the second bar must be equal to that in the first, and that it must act in an opposite direction in this case, because it has to resist the force acting through the first bar in the reverse direction. In order to illustrate this, let A B represent the last bar of the frame, and let the force act from A to B; then by the principle of the resolution of forces, if A B represent the force along the bar A B, we have by resolution this force equal to two forces, one equal to B C and acting in the direction from C to B, and another force acting in a direction parallel to A C, and in the direction from D to B; but because A B is a balanced force, therefore these forces BC and BD must lie in the reverse directions, viz., from B to C and from B to D; and now we see that the bar B C must be designed in order to serve as a "tie," whilst A B must be designed to act as a "strut;" and it is also evident that the connection at B, whether by bolts or rivets, must be so designed that it may be able to resist the shearing action due to the force represented by B D. The amount of the force acting along A B will be greater than the vertical supporting force in the proportion of A B to A U, or to express this in trigonometrical formula, we have force along A BAD cosic / BAC, or since the cosicant of an angle is equal to In the absence of sulphates. chlorate of potash, however, the use of sul- seams. A paper by Mr. key, a chemist at Otago, New Zealand, communicated to the Royal Society of Edinburgh, contains some original suggestions as to the formation of coal The agencies supposed to be at work in the formation of coal are, decomposition, heat, and pressure; but Mr. Skey considers that these are insufficient to produce coal in the state in which it actually exists. The effect of heat, for example, he speculates, would be to convert a certain amount of the material into gas, which, imprisoned in the mass, would give it a vesicular structure which no amount of pressure afterwards applied would suffice to remove. Mr. Skey's own notion appears to be that coal owes its actual compact condition to the power it possesses of absorbing o anic matters (and saline matters also to some extent) from their solutions in water. This absorptive power, he says, will enable the coal to arrest those organic matters contained in common water, of the stress in all the bars from the point and a continual supply of such being kept of support to the point of application of up by the flow of water down to the level of the load, if the load was not a distributed the sea carrying the necessary material, we one. In the case of a distributed load may have the compactness of the same largely this stress will vary from its greatest augmented. In his experiments, Mr. Skey intensity at the points of support towards used the brown coal, or lignite, of New Zeathe part of the girder traversed by the land, which is generally believed to illustrate resultant of the load, at which point it will an intermediate stage of coal formation. This 1 sine of the same angle' AD sin BAC' we get A B = and this would be the value seems to promote the action of ozone on the paper, and to get strictly ozonic effects it is necessary that the papers should be protected from direct sunlight. The amount of coloura tion due to diffused light should also be allowed for before the results are stated. The source of ozone (not the only one, however) Dr. Daubeny finds to be the respiration of growing plants, which is abundantly proved in the paper from which we quote; and the learned author is therefore led to the conclusion that vegetable life acts as the appointed instrument for counteracting the injurious effects of the animal creation upon the air we breathe, not merely by restoring to it the oxygen which the latter had consumed, but also by removing, through the agency of the ozone it generates, those noxious effluvia which are engendered by the various processes of putrefaction and decay. A new explosive compound which may be susceptible of some practical applications has been described by Mr. Peter Griess. It is a salt named by the author nitrate of diazobenzol, which is prepared by passing nitrous acid through a solution of aniline in four times its volume of alcohol. The gas is passed through this solution until the addition of ether to a small portion causes the copious precipitation of white acicular crystals. When this point is reached the whole of the reddishbrown liquor is mixed with ether; the crystals are then allowed to subside, and separated as The inroads of far as possible from the mother liquor. They universe. And when we consider the character work from Belgium, and it is the case also with are then taken up with cold dilute alcohol, of these great discoveries, most of which have regard to some works we are now carrying out in and re-precipitated by the addition of ether, transpired within the last century, we cannot Ind a, where the ironwork is actually shipped when they are obtained as long white needles. shut out from our thoughts that the destiny of from Belgium to London, and re-shipped to When obtained, they must be treated with mankind must be necessarily improved by every Bombay, at a less cost than it could be purchased I cannot but view the greatest care. They must be dried in the fresh conquest achieved over the worlds of from English manufacturers. There is, indeed, a sort of these circumstances with regret and apprehenair or over sulphuric acid. Heated even below nature and art. 100 deg. Centigrade they explode with tre- majesty fringing the dawn of civilisation, bid- sion, and I hope that before such a state of mendous violence, far surpassing that of ful-ding us to strive and hope. It is now approach- things is permitted to become more serious, ing two centuries since the discovery of applying some co-operation may be induced amongst our minating silver. The destructive action of steam as a motive force was made by the Mar- leading manufacturers, so that this branch of our the explosion is extreme. Iron plates several quis of Worcester. This discovery has since industry may not be altogether wrested from us. lines in thickness were found smashed to become the principal means by which all the I mention these instances as facts which have atoms when something more than 15 grains of leading arts and industries of our time are carried come under my personal observation and expethe substance was exploded upon them. on. It has brought into existence a means of rience. We find one of our leading railway Friction, pressure, and concussion also cause inland communication which, but for the gradual companies (the Great Eastern Railway) being the explosion. The smallest particles acci- way in which it has entered into our system provided with locomotives from France, which dentally dropped upon the floor of a room of life, would be thought marvellous. It is in- resulted after a competitive tender to which our when dry exploded when trod upon, emitting dispensable to the business of the world that leading firms were invited. flashes of light. It may be as well to repeat railways should be constructed through every foreign competition have at length reached to the author's caution that the manipulation of habitable part of the globe. Having originated such an extent that one of our leading railway such a substance necessitates the greatest pre-tive system extending on a large and comprehen- our manufacturers for the supply and erection of in our own nation, we at length see the locomo- companies invited a French firm to compete with sive scale around us, and we shall, no doubt, yet the ironwork of their terminal station in London. realise some important improvements, both as to I cannot, therefore, but repeat that there are the rapidity of transit and the distance to be good grounds for the fears entertained with traversed, either by improvements upon our pre- respect to this branch of our industry, and trust sent railway system or by a somewhat analogous that these remarks may lead to some practical system of locomotion to that at present in opera- suggestions being made during the present session, with the view of ameliorating the present Rivers offer no obstructions to railway inter-condition of our iron manufactures. communication but such as have already been surmounted. At the present moment it is proposed to bring together nations between which there is a sea of twenty miles, and there would appear to be no substantial reason to consider this task impossible, either by the construction of a multiple span bridge or a subway across. Such a work would have a marked effect not only upon the nations thus linked together, but its results would be equally felt at the remotest distances between which communication was possible. caution. A SOCIETY OF ENGINEERS. Ta meeting of the Society of Engineers, held on Monday evening last, Zerah Colburn, Esq., President, in the chair, the accounts for 1866 were read, and premiums of books were awarded to Mr. Carl Wessely for his paper on "Arched Roofs;" to Mr. Thomas Cargill, for his paper on the "Railway Bridge Place de l'Europe, Paris;" and to Mr. Arthur Jacob, for his paper on "Reservoirs and Embankments." Mr. Col. burn then introduced W. H. Le Feuvre, Esq., the President for 1867, who took the chair, and deivered his inaugural address, which extends to so great a length that we are compelled to content ourselves with the following interesting extracts therefrom: The Society of Engineers has at length attained such a position in the scientific world that it cannot but afford gratification to those gentlemen who, some twelve years ago, united with the view of establishing it. One of the main objects of this society was to call together those various practical sciences allied with the engineering profession, and in this the society has met with the happiest success. It at present numbers amongst its members some of the foremost practical men of our time, and not in one branch of the profession alone. It may be said, indeed, that there does not exist a society with kindred objects possessing so many and varied elements of future success within it. Amongst our members and council we have men of large experience in works of design, construction, and art, in boiler and marine engineering, electrical engineering, iron shipbuilding, gas, ordnance, railway, and hydraulic engineers, inventors, and designers of some of the most valuable processes of machinery employed in connection with the arts and manufactures of our time. I ask myself to what elevation may not a society, possess ing such advantages as these, hope to rise ? We must not forget, too, that favoured more than any association of a similar character, we possess the singular privilege of having upon our council the representatives of the leading scientific journals of the day. We had for our president last year a gentleman who had for many years been editor of the Engineer, and who now conducts the new scientific journal Engineering, which is devoted to the objects of our profession. We have also the present editor of the Engineer upon our council, and the editor of the MECHANICS' MAGAZINE, who, in company with some of the older and more assiduous members of the society, may be said to have watched it from its cradle. The late lamented Mr. Parkin Jeffcock, whose life was so heroically sacrificed at the Barnsley colliery explosion was, as is well known, a member of our society. Should that spirit of fellowship which pervades and links together such associations as ours stimulate some amongst us to devise a means of providing against, or at least mitigating, these dire and almost measureless disasters, Mr. Jeffcock's life will not have been sacrificed in vain. doubt remains much before us to be accomThere no plished. The invention of the locomotive has called an entirely new era into existence. The discovery of the mariner's compass has knit all the satellites of the human race into one great family, as gravitation linked together all the planets of the tion. To In relation to the question of colliery accidents it seems singular that the material of which the Davy lamp is made has not been employed in mines in any other form than that of a portable lamp subject to accidents of various kinds. It would be probably worthy of trial, whether this material could not be employed to much greater advantage in the form of large chambers, divided into compartments, within which numerous lights might be enclosed, and prevented under any circumstance from being exposed to contact with the surrounding air. It would be possible by some With regard to the possible acceleration of the system of this kind to light up mines by gas rate of transit, we have already upon trial a sys-light, and so to supersede the use of the Dary tem of pneumatic locomotion which may alto- lamp by distribution amongst the men. gether revolutionise our railway system. It is secure the safety of those engaged in mining even in its present undeveloped form discovered operations, it has been proved beyond doubt to be a most important auxiliary. It is singular that the number of shafts should be increased. with what a repetition of indifference discoveries Should this be enforced by the Legislature, it of this nature seem to dawn upon us. It is in would, no doubt, greatly tend to the preservation cases of this description, where investigation of life, as, in the event of any casualty occuring. may be made on scientific grounds, that societies the diffusive energy of the atmosphere would like ours should step in to give to the world more readily come to the relief of those not the benefit of discoveries which otherwise might immediately sacrificed, and restore them to con. be put off for fifty or a hundred years, if not sciousness. altogether lost. Now there could not be any. thing more important to this country, considering the present condition of its railways, than the discovery of a quicker means of transit than that now in use. It is requisite that important changes should be made in the railway system in use amongst us, either by the Legislature taking some interest in its behalf, or by some method of co-operation or amalgamation between the various companies. It might not be injudicious to invite the assemblage of a railway parliament or congress, so that substantial and profitable laws should be enacted for the control and management of the extensive system of railways which now aid so materially in the development and well-being of the nation. The extensive improvements which are now in course of completion as to the facilities for producing large quantities of iron and steel in the northern district of the kingdom, are inso me measure owing to the large demands made for these materials on account of improved systems of naval architecture lately introduced into this country. We are now more strongly impressed than ever with the advantages of iron and steel in place of wood in the structure of ships After thirty years' practical experience, the only objections which can be raised against iron ships are the liability of the bottoms to foul by the adhesion of vegetable and animal substances, and the derangement of the compasses by the local attraction of the iron in the hull. The ad. I would desire to call your attention also to a vantages an iron ship possesses over those built circumstance which has lately begun to assume a of wood are numerous. Superior strength, more serious importance to us as engineers, and which certainty in the quality of material, greater durapromises to endanger one of the most extensive bility, reduced weight, less cost, and more carry; of our manufactures, that is, the production and ing capability. As iron has superseded wood manufacture of iron. This has been carried on for ships in consequence of the many advantages to such an extent now in Belgium that, after an it possesses, the question for our consideration is interval of a very few years, the run of competi- whether we should not employ steel in place of tion is altogether on the side of Belgian manu- iron. We may assume the tensile strain of iron facture. They successfully compete with the would bear half the strain of steel; this would most extensive of our ironworks in England. As show that nearly half the weight of steel might examples, I would mention that during the pro- be adopted as an equivalent for iron; and congress of the Exhibition lately erected in Amster-sidering it commercially, the price of Bessemer dam, it was found that while the earlier portions steel plates at £20 per ton, as compared with were being constructed it was cheaper to iron plates of £10 per ton, a considerable saving import the ironwork from England; but before might be effected by a vessel being able to carry the works were completed a considerable quan- additional cargo equal to the increased difference Holland, as it could be obtained at a lower price, tity of ironwork was supplied from Belgium and of weight, without additional cost. The future water supply of our towns is a suband from that period to the present the competi|ject for our earnest consideration. Comprehen. tion has run hard between those countries and sive measures have been laid before the public by our own. In the new Pimlico Wheelworks, in some of the leading engineers of the day for the London, which, as may be known, perhaps, to supply of our largest towns. It is certain that most of you, was constructed by our firm, we an entirely new or an additional supply of water had also to give way to the importation of iron- must be had, and the sooner the better. It is desirable that Parliament in dealing with this question should consider it as affecting the whole of the towns and cities in this country, as we may hereafter find that our metropolis as a pure and abundant water supply, and towns in the immediate vicinity of the source of supply will have to depend on bodies or corporations who have no interest beyond the particular town or city they represent. A general scheme ought to be devised for supplying the future wants of all the large towns and cities in the island of Great Britain with pure and abundant water supply. During the past year considerable attention has been bestowed on the science of aeronautics, the department relating to the mechanical ex pedients and inventions for facilitating aerial navigation, and obtaining or aiding a change of locality at the will of the aeronaut, is a subject of great interest to the engineer. As railways have superseded our highways, I cannot but think that aërial navigation may, at some future day, supersede our railways. The act of flying is purely a mechanical action, and it seems remarkable that no correct demonstration has ever been given of the combined principles upon which flight is performed. The ascent of the first aërostat in France, no doubt, excited much ridicule; but, how many apparently ridiculous things have been overcome, and of what signal use they are to the present age? Providence to have ordained." Let us, then, be guided by these sentiments, and recognise that in the fulfilment of these hopes we are daily ac quiring the co-operation of nature and science which has at length united the Old and New worlds, and in view of these triumphs, we cannot fail to perceive that it is reserved to us to take the initiative in all that may tend to advance the welfare and glory of mankind. number of assistants who have been educated in The application of steam power to the cultiva- As engineers engaged in carrying out works in all parts of the civilised world, it is very desirable that a universal system of weights and measures should be adopted. The permissive Act of Parliament of 1864, which has legalised, the present standards of measure decimalised, and also the metre, has now become a vital and urgent question for our consideration, on account of the number of circumstances affecting it. I am in favour of adopting the metre as our standard of measure in consequence of its adoption by so many countries, and, consequently, on Inventors and inventions subject to the patent account of the great advantage that would attend laws of this country labour under many disthe universal use of the same system. The metre advantages. They are supposed to have the was determined by measuring a portion of a privilege granted by the State of a monopoly quadrant of the earth's polar circumference. for a period of fonrteen years, to reap whatever The inch was defined by Act of Parliament. pecuniary benefit might be derivable from their The length of either the metre or the inch may invention; but it need hardly be stated that this be equally verified, so that in this respect there is not the case, owing to the incomplete nature is no choice between the one or the other. The of the information afforded by the Patent Office metre is the standard most extensively and as to the novelty of inventions. An inventor influentially in use, and consequently involves after having, with great expenditure of time, the least alteration of existing measures. The trouble, and money, perfected his invention, goes metre is in use thronghout the French empire, to the further expense of having a complete Belgium, Holland, Italy, Spain, Portugal, Greece, Brazil, Peru, Chili, Mexico, and other countries in America. The inch is in use throughout the British empire only, so that the change to the metre as a universal standard can be practically carried out by our adopting the metre, not only as a permissive, but as a compulsory measure in this country. stantial improvements in our patent laws may H BY PROFESSOR TYNDALL. HE sounding of a hydrogen flame when enclosed within a glass tube was, I believe, first noticed by Dr Higgins, in 1777. The subject has since been investigated by Chladni, De La Rive, Faraday, Wheatstone, Rijke, Sondhauss, and Kundt. The action of unisant sounds on flames enclosed in tubes has been investigated by Count Schaffgotsch and my self. The jumping of a naked fish-tail flame in response to musical sounds was first noticed by Professor Lecomte at a musical party in the United States. He made the important observation that the flame did not jump until it was near flaring. That his discovery was not further followed up by this learned in. vestig for was probably due to too great a stretch of courtesy on his part towards n yself. Last year, while preparing the experiments for one of my "Juvenile Lectures," my late assistant, Mr. Barrett, observed the effect independently; and he afterwards succeeded in illustrating it by some very striking experiments. With a view to the present discourse, and also to the requirements of a forthcoming work on sound, the subject of sounding and sensitive flames has been recently submitted to examination in the la boratory of the Royal Institution. The principal results of the inquiry are embodied in the following abstract. Pass a steadily-burning candle rapidly through the air, you obtain an indented band of light, while an almost musical sound heard at the same time announces the rhythmic character of the mo tion. If, on the other hand, you blow against a candle-flame, the fluttering noise produced indicates a rhythmic action. When a fluttering of the air is produced at the embouchure of an organ. pipe, the resonance of the pipe reinforces that particular pulse of the flutter whose period of vibration coincides with its own, and raises it to a musical sound. When a gas-flame is introduced into an open tube of suitable length and width, the current of air passing over the flame produces such a flutter, which the resonance of the tube exalts to a musical sound. Introducing a gasflame into this tin tube three feet long, we obtain a rich musical note; introducing it into a tube six feet long, we obtain a note an octave deeperthe pitch of th note depending on the length of the tube. Introducing the flame into this third tube, which is fifteen feet long, the sound assumes extraordinary intensity. The vibrations which produce it are sufficiently powerful to shake the pillars, floor, seats, gallery, and the five or six hundred people who occupy the seats and gallery. The flame is sometimes extinguished by its own violence, and ends its peal by an explosion as loud as a pistol shot. The roar of a flame in a chimney is of this character: it is a rude attempt at music. By varying the size of the flame, these tubes may be caused to emit their harmonic sounds. search made among the patent records, to ascertain the fact that his invention has not been patented before, and this search proving satisfactory, he applies for his patent. No sooner, however, has a description of his invention appeared in print than he is informed that the identical invention has previously been made and commercially used, though not patented or made The training of the more useful branches of our generally known; thus the patentee finds himself profession is a subject of paramount interest to in the position of having spent his time and our society. Indeed, the origin, rise, and pro- money to no purpose, without having any posgress of this society is attributable to the co-sible means at his command, whereby he might operation of some of the earlier students of the have obtained the information before taking out Engineering College, at Putney, who could not his patent. It is to be hoped that some subperceive any favourable opportunity of advancing in their profession by following out a course of collegiate instruction. The Engineering College, I cannot conclude my observations without at Putney, was established with a view to pre- making reference to the approaching exhibition pare and train the student in the art and practice in Paris. Our age has been one of exhibitions, Passing from large pipes to small ones, we of an engineer, so that at the expiration of his and there can be no doubt that they have a great obtain a series of musical notes, which rise in term of pupilage he would be duly qualified to influence upon the education of the people. Our pitch as the tube diminishes in length. This enter upon the duties of his profession. Those own exhibition in Hyde Park ushered in a new flame, surrounded by a tube 173in. long, vibrates qualifications which are necessary before one can order of ideas. All the inequalities of nature 459 times in a second, while that contained in this undertake the responsibility attached to an en- were then for the first time brought under one tube, 103in. long, vibrates 717 times in a second. gineering appointment can never be satisfactorily vast roof for contemplation, and those who had Owing to the intense heat of the sounding column, acquired by a theoretical course of instruction not made a journey round the world had an these numbers are greater than those correspond. alone, and I would call the especial attention of opportunity of witnessing the products and ing to organ-pipes of the same lengths sounding those younger members of our profession-I manufactures of all its nations. Since then in air. The vibrations of the flame consist of a would desire to make all those in any way in- there have been exhibitions in New York, Paris, series of partial extinctions and revivals of the terested in this subject, sensible of the advantages Dublin, Florence, Munich, and Holland. Our flame. The singing flame appears continuous; which would necessarily follow a punctual and Prince Consort was the first whose genius called but if the head be moved to and fro, or if an regular attendance at all our meetings. The all the various races of mankind into society. opera-glass, directed to the flame, be caused to practical information which is elicited during the The words uttered by him at the period of our move to and fro; or if, after the method of discussions of papers read, and the great variety, first exhibition have gradually become the faith Wheatstone, the flame be regarded in a mirror as well as valuable character of many of the sub- of all the civilised nations by which we are which is caused to rotate, the images due to the jects treated of, would form an essential part of surrounded, and their influence will continue revivals of the flame are separated from each the education of any engineer. As members of until the aspirations from which they originated other, and form a chain of flames of great beauty. the Society of Engineers, we ought to devote are more or less fulfilled. "Gentlemen," said With a longer tube and larger flame, by means some portion of our time to the students who the Prince, "I conceive it to be the duty of every will eventually succeed us in our profession, and educated person closely to watch and study the try to remedy the defects now existing in their times in which he lives, and as far as in him training and course of instruction. I may state lies to add his humble mite of individual exertion that from my own personal knowledge, having a to further the accomplishment of what he believes of a concave mirror, I can project this chain of flames upon a screen. I first clasp my hand round the end of the tube so as to prevent the * Read before the Royal Institution of Great Britain, January 18, 1867. flame falls to a height of 9in., the smoke dis- already containing coin, knocks the flame down. are current of air which causes the flutter from Against a broad bat's-wing flame I allow a sheet of air, issuing from a thin slit, to impinge. A musical note is the consequence. The note can be produced by air, or by carbonic acid; but it is produced with greater force and purity by oxygen. The pitch of the note depends on the distance of the slit from the flame. Before you burns a bright candle-flame; I may shout, clap my hands, sound this whistle, strike this anvil with a hammer, or explode a mixture of oxygen and hydrogen. Though sonorous waves pass in each case through the air, the candle is absolutely insensible to the sound; there is no motion of th flame. I now urge from this small blow pipe a narrow stream of air through the flame of the candle, producing thereby an incipient flutter, and reducing the brightness of the flame. I now sound the whistle; the flame jumps visibly. Matters may be so arranged that when the whistle sounds the flame shall be either almost restored to its pristine brightness, or that the amount of light it still possesses shall disappear. Before you now burns a bright flame from a fish-tail burner. I may, as before, shout, clap my hands, sound a whistle, or strike an anvil; the flame remains steady and without response. I urge against the broad face of the flame a stream of air from the blow-pipe just employed. The flame is cut in two by the stream of air. It futters slightly, and now when the whistle is sounded the flame instantly starts. A knock on the table causes the two half-flames to unite and form for an instant a flame of the ordinary shape. By a slight variation of the experiment, the two sideflames disappear when the whistle is sounded, and a central tongue of flame is thrust forth in their stead. Passing from a fish-tail to a bat's-wing burner, I obtain this broad steady flame. It is quite in. sensible to the loudest sound which would be tolerable here. The flame is fed from this gasholder, which places a power of pressure at my disposal unattainable from the gas-pipes of the Institution. I turn on more gas: the flame enlarges, but it is still insensible to sound. I enlarge it still more, and now a slight flutter of its edge answers to the sound of the whistle. Turning on a little more gas, and sounding again, the jumping of the flame is still more distinct. Finally I turn on gas until the flame is on the point of roaring, as flames do when the pressure is too great. I now sund my whistle; the flame roars and thrusts suddenly upwards eight long quivering tongues. I strike this distant anvil with a hammer, the flame instantly responds by thrusting forth its tongues. Another flame is now before you. It issues from a burner, formed of ordinary gas.tubing by my assistant. The flame is 18in. long, and smokes copiously. I sound the whistle; the The pitch of the note chosen to push the flame over the brink is not a matter of indifference. I have here a tuning-fork which vibrates 256 times in a second, emitting a clear and forcible note. It has no effect upon this flame. Here are three other forks, vibrating respectively 320, 384, and 512 times in a second. Not one of them produces the slightest impression upon the flame. But, besides their fundamental notes, these forks can be caused to sound a series of overnotes of very high pitch. I sound this series of notes: the vibrations are now 1,600, 2,000, 2,400, and 3,200 per second respectively. The flame jumps in response to each of these notes; the response to the highest note of the series being the most prompt and energetic of all. To the tap of a hammer upon a board the flame responds; but to the tap of the same hammer upon an anvil the response is much more brisk and animated. The reason is, that the clang of the anvil is rich in the higher tones to which the flame is most sensitive. Here, again, is an inverted bell, which I cause to sound by means of a fiddle-bow, producing a powerful tone. The flame is unmoved. I bring a half-penny into contact with the surface of the In our experiments downstairs, we have called this the vowel flame, because the different vowel sounds affect it differently. Vowel sounds of the same pitch are known to be readily distinguishable. Their qualities or clang-tints are different, though they have a common fundamental tone. They differ from each other through the admix. ture of higher tones with the fundamental. It is the presence of these higher tones in different proportions that characterises the vowel sounds, and it is to these same tones, and not to the fundamental one, that our flame is sensitive. I utter a loud and sonorous U, the flame remains steady; I change the sound to O, the flame quivers; I sound E, and now the flame is affected strongly. I utter the words boot, boat, and beat in succession. To the first there is no response; to the second, the flame starts; but by the third and fourth it is thrown into violent commotion; the sound Ah! is still more powerful, When the vowel sounds are analysed their constituents are found to vary in accordance with the foregoing experiments; those characterised by the sharpest overtones being the most powerful excitants of the flame. The flame is peculiarly sensitive to the utterance of the letter S. If the most distant person in the room were to favour me with a "hiss," the flame would be instantly shivered into tumult. The utterance of the word "hush," or "puss," produces the same effect. This hissing sound contains the precise elements that most forcibly affect the flame. The gas issues from its burner with a hiss, and an external sound of this character added to that of a gas-jet already on the point of roaring is equivalent to an aug mentation of pressure on the issuing stream of gas. I hold in my hand a metal box containing compressed air. I turn the cock for a moment so as to allow a puff to escape-the flame instantly ducks down, not by any transfer of air from the box to the flame, for I stand at a distance which utterly exclu es this idea; it is the sound of the issuing air that affects the flame. The hiss produced in one orifice precipitates the tumult at the other. [We may state for the information of readers who may wish to repeat any of the interesting experiments described by Dr. Tyndall that the one thing necessary to their success is to have the gas delivered with a steady equable pressure. The lecturer made use of a small gasometer, and did not depend on the ordinary service pressure, which is liable to frequent fluctuations.ED. M. M.] bell; the consequent rattle contains the high IN LOSS OF "LA SEINE." N the Naval Intelligence of last week we referred very briefly to the raising and floating of this vessel, which, by the ability and per. severance of M. Eyber, had been placed in a situation of comparative security, and hopes were reasonably entertained that when the weather permitted she might be run into port, and restored to her owners. Our readers will learn with much regret that these hopes have been doomed to be disappointed in a double sense. M. Eyber, who had returned to Paris to make further researches respecting the final accomplishment of the enterprise he had been so assiduously engaged in for many months, and was on the point of setting out again for the scene of his labours, unhappily met his death in a sudden and accidental manner. Almost at the same time despatches arrived from the captain, who had been left in charge of the recovered vessel, that the violence of the last tempest which raged along the Calabrian coasts was too impetuous for "La Seine" to withstand, and, according to the captain's own words "the vessel has been smashed to pieces." By his unfortunate demise M. Eyber was spared the pain and mortification of witnessing the complete and unmerited failure of his arduous labour and perseverance, although it is possible that had the same powerful hand been present when the tempest was at its worst it might have possessed on the flame. from that distance produced instantaneously the same effect the same saving influence it exercised on many similar previous occasions. Here is another flame 20in. long. I take this fiddle in my hand, and pass a bow over the three strings which emit the deepest notes. There is no response on the part of the flame. I sound the highest string: the jet instantly squats down to a tumultuous bushy flame, 8in. long. I have here a small bell, the hammer of which is caused to descend by clockwork. I hold it at a distance of 20 yards from the flame. The strokes follow each other in rhythmic succession, and at every stroke the flame falls from a height of 20in, to a height of 8in. The rapidity with which sound is propagated through air is well illustrated by these experiments. There is no sensible interval between the stroke of the bell and the shortening of the flame. Some of these flames are of marvel lous sensibility; one such is at present burning before you. It is nearly 20in. long; but the slightest tap on a distant anvil knocks it down to 8in. I shake this bunch of keys or these few copper coins in my hand; the flame responds to every tinkle. I may stand at a distance of 20 yards from this flame: the dropping of a sixpence from a height of a couple of inches into a hand *The bell was carried into the gallery of the theatre and MR ments on MACHINERY FOR DRESSING SILK. R. THOMAS GREENWOOD, the wellknown machinist of Leeds, has recently patented an invention which relates to improvea patent obtained by him about two years since in conjunction with Mr. Herbert Hadley, for machinery for dressing silk waste. This machinery was provided with a rotary drum which received upon its periphery the "books" of silk to be operated upon and presented them to travelling, combing, or dressing surfaces. The books were clamped and released automatically by the aid of bars formed with wedges and put in operation by screws, but difficulties arose from time to time with respect to the adjustment of the nip. To remedy these difficulties Mr. Greenwood now proposes to substitute for the screws (which actuated the bars and drove them in endwise so as to clamp the books firmly upon the drum), a weighted incline, against which the wedging bars as the drum which carries them rotates will severally press, and by that incline be pushed home so as to secure the books of silk as they are placed in the machine by the attendant. He also provides for the automatic release of the wedged-up bars. In the accompanying engraving fig. 1 is a side elevation of so much of the improved silkdressing machine as serves to explain the in of which is also carried by a bracket on the framing; connected to the crank lever is a weighted rod F". As the incline D is kept in position by the drag of the weight on the rod (which weight may be regulated at pleasure) it will impart only a determined or regulated pressure to the bars C' as they come under its action, and receive from it the endway movement requisite for securing the books of silk in their clamps. vention; fig. 2 is a partial end elevation of the |