The English Mechanic AND WORLD OF SCIENCE AND ART. FRIDAY, SEPTEMBER 20, 1878. ARTICLES. THE ELECTRIC LIGHT. BY J. T. SPRAGUE. just as a pendulum takes as long to swing the coloured portion which our eye sees we It is the same with light, for light itself consists of rays analogous in some respects to the piano wires, as each ray has its own definite vibrating function or wave-length. But light, if compared to musical notes, is a complete diapason, each ray that we can examine containing within itself all the wave-lengths of undulation, or all the "light notes" proper to the particular source from which it issues, for just as each THERE is one peculiarity of the electric musical instrument has a certain series of light which every observer remarks sounds which it can generate, so has each upon, but which no one has attempted to source of light its own specific system of explain. It is very vivid, like a fragment wave-lengths, and as we can separate and of the sun; it is intensely white, therefore individualise each note though mingled in These separate parts of the spectrum showing all colours perfectly; it is pierc- one vast orchestral chord, so can we isolate used to be considered as containing three ingly penetrating, so that when directed as each single undulatory tone, which we then distinct forces, heat, light, and actinism; a beam we hear of people reading small know as colour, from that mingled harmony but, as with the colours, we know now that print by it at several miles distance; but it which we call light. This separation is no such difference of nature exists. There is not diffusive; illuminating neighbouring effected usually by means of a prism or is simply in, say a ray of sunlight, a graobjects intensely, and dazzling the eye at a triangular mass of glass, or other trans-duated series of wave-length tones, of which distance, yet its power is rapidly lost in parent substance; the ray of light falling VOL. XXVIII-NO 704. the slow ones act upon some forms of matter by producing the actions we call heat. At a certain rate of undulation they act upon our optical organs (these or the. other rays may produce similar perceptions in other organs fitted for the purpose, so that, theoretically, eyes are not essential to sight), producing various sensations of colour. Again, at a certain increased rate of undulation, our eyes cease to perceive them; but they have at different parts different powers of re-acting on matter, and setting up chemical changes. Just so in the case of our ears, we cannot perceive either very slow or very quick vibrations. There is a limited and intermediate audible scale just as there is a limited and intermediate visible one. The figure exhibits these facts, besides containing a great deal more than the present purpose strictly requires. The wavelengths in million millionth parts of a millimetre are those of certain well-known dark lines, or extinguished undulations in the light of the sun. Their purpose here is to show the gradual increase of rapidity or diminution of wave-length. The visible spectrum is, indeed, one octave, its various parts agreeing strikingly with those of a musical octave-the undulations at the violet end being double those at the red. The three shaded curves show the quantitative effects in the different forces of each wave-length, each "force" or action being however, to some degree, present in all parts, but proportionally to the height of the curve at each part. It is with the part known as light we have mainly to deal; and that, it will be seen, is chiefly found in the yellow portion of the spectrum. We come, then, to these facts, that what we call pure or white light, is simply a perfect "chord" of colours containing all the wave-lengths of rays, with such proportion of each set of rays as exists in the light given by our sun, and that any source of light, giving either more or less than this proportion, will have a colour. In strict fact, our sun is not pure white: it has an excess of the yellow rays, and for a reason which will be seen presently, the electric light is a more perfect or pure light than sunlight. Turning now to the heat portion of the spectrum, and bearing in mind the distinction between quantity of heat as shown in the curve, and intensity or temperature, we find that as wave-length diminishes temperature increases, temperature being thus in heat what pitch is in sound, and colour in light-the measure of the rapidity of undulation. I have tried vainly to show this upon the diagram, but the subject is 66 NOXIOUS VAPOURS AND HEALTH. not yet sufficiently studied, and the scale, dull red; but the point is this-that, rela- but there can be no question that human ke that of wave-length, is not proportional tively, those sources must give light of beings subjected constantly to the effects to the diagram, as this is based on the greater quantity," though less white, of an atmosphere tainted with-e.g., sulquantities of the colours in sunlight. How whose energy is mainly confined to produc- phuretted hydrogen-are kept below par as ever, if we take a platinum wire adjusted ing slowly undulating rays, while sources regarda bodily health, and are consequently to a suitable spectrum apparatus (fitted, of greater intensity will produce a more all the more predisposed to "take" any that is, with substances which are not only vivid light, capable of penetrating far as a disease which may happen to become epitransparent, as regards light, but also as concentrated beam, but not giving so great demic. If a man finds that the noxious regards the other rays), we find that on a body of light at a certain moderate dis- vapours given off by the manufactories in passing an electric current through it, this tance from the source. This is just what is his district produce nausea, if he finds him. wire becomes heated in known degrees ac- observed of the electric light, and also of self with a headache, or unable to eat his cording to the quantity of the current, light from the paraffin oils, while gas is breakfast after sleeping in the neighbour. which we will now suppose to be steadily defective in not having sufficient rays of hood, he is pro tanto, not in good health, and gradually increased. The actual spec- short wave-length to completely balance the and if the symptoms are produced by the trum shown in the diagram can now be gra- yellow rays and harmonise them into a noxious gases, he has good claims to be produally called into existence, built upwards white light. tected by the Legislature. It is not imfrom the left, and like a ladder, to which probable that the statistics showing only rung after rung is added. As the wire the actual mortality are very misleading as heats, a thermometer or thermopile, placed regards the general health of the district, against the screen, just where the heat whereas if returns of the sickness prevalent curve commences, will testify the presence into the working and management of had been available, the commissioners would of heat, which cannot be discovered further manufactories from which sulphuric acid, have been able to have given a more proto the right. Increasing the current gra. sulphuretted hydrogen, muriatic acid, nounced opinion. It is commonly supposed dually, this heat spreads as regularly to chlorine, ammoniacal, and other vapours or that in the neighbourhoods where volumes wards the right. At length the wire be- gases are given off, have discharged their of noxious gases are continually being gins to show a faint glow of red heat, and task with commendable skill. It was not mixed with the atmosphere epidemic then the visible spectrum commences to to be expected that the commissioners diseases rarely gain a footing, but in the form by a red stripe in the position shown; could settle all the disputed points which opinion of Dr. Richardson this belief must we continue to increase the current and the go to make up the controversy on noxious be abandoned. If there is any truth in the beat, and the spectrum grows steadily to vapours, but they have at least recorded germ theory of disease it would be no more the right; shade after shade of colour deve- their opinion wich tolerable plainness as to than reasonable to expect that in an atmo lope as the wire approaches the white heat, the effect of the vapours upon health, and sphere charged even slightly with sulwhen the visible spectrum is complete; with the evidence brought before them phurous and other vapours some of the still the band goes on extending, till at that was not so easy a task as might be zymotic diseases would fail to become epilength the point of fusion of the platinum supposed. The discharge into the atmos- demic, and it would be interesting to know is reached, these invisible rays or waves phere of the vapours of sulphur, of chlorine, on good authority whether scarlet fever, forming the actinic spectrum. We do not of ammonia, and of the numerous combina- measles, &c., prevail to any extent in know how far such a spectrum would ex- tions of those substances must of necessity Widnes, Runcorn, St. Helen's, Swansea, tend, because different testing agents cxercise some influence upon vegetable aud and the towns on the Tyne. The deathdevelop different results, the actinic spec- animal life; but while few will venture to rate and the returns of the Registrartrum shown being the measure of the assert that little harm is done to agricul- General are of no value whatever in this chemical action tending to cause hydrogen tural produce, many do assert and strenu- connection, because persons attacked with and chlorine to combine as hydrochloric ously maintain that no injury whatever is zymotic disease and already constitutionally acid gas. We see then that increased tem- done to human life even by the fearful" below the mark "through long subjection perature means increased rapidity of undu. stinks which at times emanate from some to the influence of noxious gases have a lation, and it is easy to see a reason why of our factories. As a matter of fact, sta- smaller chance of recovery than those who increasing electric current should produce tistics show that in some districts noted are as a rule constitutionally " up to the this effect. Whatever electricity may be in for the acid vapours existing in their mark." So that what is wanted to render its own nature, it is certain that what is atmosphere the death rate is actually Dr. Richardson's opinion of more value known as the electric current is attended by lower than in other places unblessed with than necessarily attaches to his name is a molecular motions in the conductor, holding; alkali and copper smelting works. On the carefully compiled return of sickness, but definite relations to the current quantity; other hand, medical officers and physicians that we are afraid there is no possibility of this is proved by the facts of electrolysis. attributed the high rate of mortality at getting. The question may thus be fairly The increased current then sets up increased Liverpool and some districts on the Tyne left as the Commissioners have put it: that molecular motion, and this we know is to the influence of the noxious emanations the gases from alkali and other works are accompanied by actions outside the con- from the manufactories. In the face of injurious to health, but not so productor, which are easy enough to connect this contradiction the Commissioners point nouncedly so as to warrant any mea with the undulatory motion exhibited in out that they are encountered in limine by sures so stringent as practically to prothe spectrum. The following list of ap- the almost insuperable difficulty of sepa- hibit the manufactures. The verdict is proximately known temperatures, corre- rating the consequences specially due to the fairly summed up by Canon Hopwood sponding to various lights, will give some emanations of the works in question from who, when asked as to the effects of suldea of this relation of the spectrum :those common to all works generating dust, phuretted hydrogen in St. Helen's, replied, smoke, and dirt, and surrounded by a dense I think that strong healthy people will population, and of deciding what propor- perhaps breathe it, and be not much the tion of mischief can justly be attributed to worse for it, if at all. At the same time I noxious vapours, the product of any manu- think it keeps many of us a few pegs lower facture. If we may accept the high death-than we should be in a better atmosphere." rates of parts of Liverpool and some towns There can be no question, too, that an on the Tyne as caused mainly by the in- atmosphere of the kind retards the recovery fluence of noxious vapours, we are con- of convalescents. Besides the so-called fronted with the low death-rates of Widnes noxious vapours, however, there are many and Swansea, and with the undoubted fact other nuisances that the Commissioners that the population in the vicinity of, and were empowered to report upon. Loud those actually engaged in, the works are outcries have been heard in recent years generally healthy. The commissioners are, from the neighbourhood of Blackheath as to therefore, unable to say that the statistics the unbearable stenches wafted to the disadvanced furnish any convincing proof of trict when the wind is in certain quarters. the injurious effects upon health of the The Metropolitan Board of Works, it will vapours in question, but they consider it be remembered, have certain powers for would be unreasonable to disregard the regulating the establishment and manage universally expressed opinion of medical ment of offensive manufactures, and men that the public health would be bene- although they are not always enforced as fitted by the still greater diminution in the they should be, the effect has been to cause percentage of noxious gases permitted to the erection of numerous factories just beenter the atmosphere. It must be remem-yond the limits of the Board's jurisdiction. bered that it is not required to prove the actual presence of disease in consequence of the noxious vapours, for there is no reason to suppose that any specific symptoms are produced by them, except, perhaps, in the case of lead works and gold refineries; Red, just visible 977° Fahr. 1,290 dull cherry, dull 1,470 full 1,650 clear Orange, deep clear 1,830 2,010 2,190 2,370 2,550 2,730 Gas, in Bunsen burner 3,500 Electric arc 14,000 As the electric arc far exceeds in temperatare every other known flame, we can now anderstand why it is that it is intensely white, and why it is so strongly charged with actinic rays; the reason is, that so large part of its energy is occupied in developing rays of short wave-length. It is true that as these more rapid waves are attained the rays of greater wave-length continue to be generated abundantly, so that Tyndall says that in one measurement he found ten times as much dark heat generated when such a wire as has been referred to was at a white heat as when it was at a be remembered. The evidence received by the Commissioners was nearly all on one side, for the simple reason that the facts cannot be disputed; but so far as the chemical manure-makers are concerned, they acknowledge, by their representatives, that effective condensation or destruction of the noxious and offensive fumes is quite practicable, although near the works a disagreeable odour will always be perceptible. All the proprietors object strongly to local inspectors, but express themselves as willing and desirous to be under the control of properly-qualified Government inspectors. The cement works near Greenhithe are a source of annoyance to the residents of that town, and potteries, candle face tories, and other sources of noxious vapours do not contribute to the health of the inhabitants of Lambeth. Differences of opinion exist in every case, for while a medical practitioner long resident in Lambeth considers that the acid vapours thrown off from the potteries are injurious to people with weak chests, Dr. Bernays, of St. Thomas's Hospital, has found no evil results to the inmates from the smells of the neighbourhood. In fact he says that the odours from the wharfs where vegetable refuse and manure from Covent-garden Market are deposited, are more offensive than the smoke from the potteries. There is no question that the hydrochloric acid gas is injurious to stonework and to trees, to plate, steel, and books, but in the opinion of Dr. Odling the quantity discharged from the salt-glazing kilns of Messrs. Doulton cannot be injurious to stone, vegetation, or human beings. We have thus the opinion of a chemist opposed to the positive statements of the Archbishop of Canterbury and the Rector of Lambeth. THE ORGAN: A COMPREHENSIVE BY JOHN WATSON WARMAN, acid. At only a few of the other copper contradicted. The evidence in this case is a works in the country is any attempt made sample of the whole. Occasional damage to prevent the escape of the sulphur fumes, is admitted, but great improvement is or to reduce their quantity; and it is prac- claimed since the passing of the Act, and tically acknowledged by the Commissioners the late outcry is attributed to the erola that any effective legislation in the case of tion of sulphuretted hydrogen from the copper works would be ruinous to the trade. waste heaps. The Commissioners conSo far as alkali works are concerned there clude by recommending that the num is evidence that considerable improvement ber of inspectors should be increased, has been effected by legislation, and reason the present standard of knowledge and to believe that better results still may be capacity being maintained; that the escap secured by a more stringent observance of of more than one grain of sulphur the Acts. In many cases crops are destroyed in one cubic foot of exit gases be by the negligence of those in charge of the made an offence; that the escape of half a apparatus at the works, a single discharge grain of nitrogen in the form of an acid in of chlorine or acid escaping from the works a cubic foot of exit gases be made an being sufficient to destroy a crop in the offence; that the deposit of alkali waste, so vicinity. As a rule these escapes are of rare as to cause a nuisance be made an offence; occurrence, and compensation is at once paid and that chemical manure works, tar diswithout any dispute; but as to the damage tilleries, coke ovens, &c., be subjected to done by the percentage of noxious gases inspection. These are the chief of the allowed to escape in ordinary working great recommendations, which practically include diversity of opinion was exhibited by the all noxious or offensive trades. There is a evidence. In very many instances, too, special exception as regards sulphur in all where damage to vegetation is undoubted, cases where endeavours are made to convert it is clearly shown that no pecuniary injury sulphur gases into sulphuric acid, and has been done to the landowner, because the far as certain other noxious vapours are presence of the alkali works has raised the concerned, the Local Government Board value of the land, houses having been built is to be permitted to fix, by a provisional and inhabited by people who buy whatever order, to be confirmed by Parliament, vegetables can be supplied to them. The "standard of escape." Taking into consicase of Sir Richard Brooke is probably the deration the interests involved, we think worst instance of withered land surface in the report of the Commissioners deals very the whole of England. His woods and fairly with the subject, and without andaly Park are situated about two miles from hampering profitable industries it suggests Runcorn and Widnes, and his property has further measures for remedying the evils according to his own statement "deterior- complained of, which can easily be applied ated in every way." His agent and some of under the sanction of Parliament. his tenants gave similar evidence. Fine old trees have been destroyed, cattle do not thrive, and are sometimes injured by eating the poisoned grass. The farms have been As to the question of injury to property depreciated in value, and are either let at by the discharge of noxious vapours there reduced rents, or at the same rental on is ample evidence to show that it has much condition that the landlord pays the abated since the passing of the Act of damages done to the crops. Much of the 1874, and although manufacturers have evidence for destruction was, however, PART been compelled to erect plant for the con- denied, and it was stated that the damage densation of acid and other gases, they have to trees was done before the passing of the obtained a fair rate of interest on the out- Act of 1863; it was also stated that the lay by the sale of the condensed products. value of land had largely increased, not only As a rule the alkali manufacturers ap- in selling price, but in the rents obtainable proved of the Act, and admitted that great an increase which was affirmed to be larger benefit has resulted from the action of the in the near neighbourhood of the works inspectors, who had often suggested im- than at distances inaccessible to noxious provements in processes, and helped to vapours. The damage caused by alkali raise the general standard of management. works was due partly to inadequate inspecThe alkali-manufacturers, the landowners, tion, and mainly to accidental escapes of and the witnesses generally were in favour gas which could be readily traced, and the of an increase in the number of inspectors, damage compensated by pecuniary paywho should be independent of the local ments. A great deal of evidence was taken authorities. Mr. Hussey Vivian, M.P., was in support of these statements. Some of the only witness altogether opposed to the witnesses, while admitting the great inspection, objecting as a "free English- damage formerly done, and the injury that to having persons running over is even now not unfrequently inflicted upon his works and prying into everything the crops, stated that in 1860 the land at they pleased. We have not the actual and about Widnes was worth only from questions and answers before us, but it £30 to £40, whereas suitable sites within would be interesting to know what is Mr. half a mile of Widnes works have recently Vivian's idea of a "free Englishman." sold at the rate of from £1,600 up to £4,800 Every resident of this country is free to do per acre. No land within half a mile of the as he pleases, so long as he does not trans- Widnes Post-office can now be bought for gress the law, but no Englishman is free to less than £1,200 an acre. Mr. Wigg, manaannoy or injure his neighbours. Mr. ging director of a soap and alkali company, Vivian's argument that aggrieved in stated that he farmed 600 acres close to dividuals should be left to seek compensa- Widnes and Runcorn, and that since the tion at the hands of the law, though sound passing of the Acts of 1874 his crops had enough on paper, scarcely bears touching not suffered any damage, but were as fine, with the needle of practice, for what free- and his cattle as good, as any in the counholder farming a few acres would not try. He further stated, while admitting hesitate a very long time before he ventured the damage done to Sir R. Brooke's estate to seek damages from a rich and power- in past years, that the Lancashire estate ful copper-smelter at the hands of the alone, consisting of 1,200 acres, was now lawyers? It is only just, however, to say worth more than the two estates together that no firm could possibly have done more in 1860-the Cheshire estate consists of than the Vivians to remedy the evils which 5,200 acres. He also asserted that the total appear to be inseparable from copper works, rental of Sir R. Brooke's farms in Cheshire for at a cost of some £60,000 they have had been considerably increased during the erected plant by which they are enabled past 20 years, and that the greatest in to utilise a large percentage of the sulphur crease was on farms nearest the works. It products for the manufacture of sulphuric is significant that these statements were not man I.-GENERAL TREATMENT IK MANUFACTURE. p. Swell Organ. Here all just said applies equally, except that full chords are of constant and legitimate occurrence on Swell, thus diminishing effectiveness of Borrowing but this is more than counterbalanced by the incident of the Box; for, although-as will presently be made more apparent-it is not to be considered that the Box can be any smaller. unless the Borrow be by Action (for which more admissible for boxed Pipes than anywhere reason the latter method may be considered as else on Manuals), yet, as has been well observed by Hopkins (par. 1164), the secret of the good effect of many Organs lies in their comparative emptiness; and this must apply with still more force to the Swell-box, for here reverberation is much more distinctly called into play: besides this there is another reason why Borrowing is more admissible here-viz., that if done by the action-method the Box is of course got smaller, because-Groovings being absent-there is of course no necessity for keeping Sliders apart; in fact, no blank or Dummy Slider at all. It will, however, be obvious that not much is gained here, as Action borrowing is not convenient for more than one Stop or so on a Soundboard (see 24, u.) q. There is yet another reason why Borrowing may be more fully resorted to on the Swell allows Soundboard to be shorter; and this viz., that an increase in depth of Box decreases the length-and consequently the drag-momentum or resistance-of the Shutters. It is true that this will throw the back Stope more into shade, but there can be no doubt that this very depth has its advantages in point of effect-that is, it adds to the distant feeling or sound of the Swell Pipes. The foregoing, re member, applies equally well to the boxed pertion of a Solo or any other Section. There is ye another reason for using groove borrowing more in the Swell-viz., that latter is often of erly Gam. G compass; thus an additional depth not make the total area excessive. All rights reserved. r. These last two reasons obviously apply in both cases. And it may thus be accepted drawn every knob would obviously be equivalent only to Wind borrowing. that when it is certain that only a soft tone to two. Thus, the Bourdon might be out freely, s. On the Swell, therefore, we may, I think, will be required, and it is not designed to so a soft 32 and 16 secured. The drawing of lay down the following:t. The Double may be freely borrowed from on one Soundboard, the Wind method will be Violoncello, the four Stops, making a very beauthe Stopt Diap. or its representative: Har- preferable, but in no other case: but it must tiful combination. If more be required draw monic Flute 8ft. is not likely to be present, but be as distinctly understood that in all Pedales, Harmonic Flute 4ft. may be borrowed from except either those of Chamber Organs, or such Harmonic Piccolo, which latter, for a variety of as consist of but one Stop (this, in author's reasons (see Depart. of SPECIFICATIONS), is opinion, is too small for any, even the smallest Pedale), the Action method is the better. The peculiarly suitable for the Swell. following may, I think, be considered the exact treatments best to follow in all cases. borrow more than one Stop in either direction the Violone would at once add it and the u. The Clarion may be freely borrowed from Cornopean or Trumpet by means of Action (a separate Pallet and heavier wind are here assumed), take care that touch be not rendered too heavy. This is not, however, worth while unless heavier wind used for Reeds. v. Ten. C Open Diap. may be borrowed from Principal, which will be of large enough scale for Swell Open Diap. w. Same rule with respect to Twelfth as in Great Organ (26, 1.). b. (a) In Chamber or other soft Instrument the Pedale may freely consist of two Stops viz., a Bourdon over its wind, and an 8ft. bor. rowed from it, with an extra top octave (or, at any rate, Pipes up to C) for latter; this is assuming Organ small. c. (b) Larger Instruments of same kind may have two Stops over their wind-viz., a 32 and an 8ft.; a 16 obtained from the former, and a 4 from the latter; top portion of 4ft.. treated as just stated (in a). Note, the 32 not to descend lower than G GG, and as it is certain never to be required without the 16ft., it (the 32) may, if please, be dumb below G G G; if desire otherwise, borrow those notes from the 16ft. x. Solo Organ. First read all that has just been said with regard to Swell, the same rules always applying here so far as relates to Box, and to shortness of compass, which latter is now still more liable to stop at Gam. G. In addition to this there are here other reasons for berrowing freely. First, the Clavier being so largely d. (c) Inlarge organs, where money is scarce, used by single finger the borrowings are effec- a very good plan will be to give the entire tive-that is, every note is then doubled. Pedale a Super-octave movement; this method Secondly, Box shutters will often bring two is very common indeed, but as generally pracSliders a good distance apart, of which advan- tised it has two important defects-1st, the tage is always, as a rule, furnished to borrow additional Pipes are not added at top; 2nd, the a 4ft. Harmonic Flute from the Harmonic Pedale remains as deficient as ever in depth. Diap. inside the Box. Thirdly, the Tuba The first defect is serious; if Pipes go no Mirab. will certainly be on a heavier wind, and higher than the Clavier, it will be manifest that a Tuba Clarion may easily be Action-borrowed the top octave of the Pedal-board remains as from it. If the Pallet be a good one (see badly off as before; and even if the range be as ROCKING kind, Dep. of PALLETS) there will be high as F (quite unnecessary, see 129, p.) it yet no fear for the touch, and there is generally in remains a fact that the Bass of the simplest this instance Pneumatic for Solo to Great. Psalm-tune cannot be played through as it Fourthly, by borrowing from a Stop inside a stands, without a break; for it will be certain to Box the latter will be practically containing rise above F-that is, the second F from the and affecting more Registers than are actually bottom (I am, of course, assuming C Pedals), inside it. and the moment it does so there will be the y. With the two exceptions just mentioned it is not recommended to borrow by wind on the Solo, for it is so absolutely necessary that every Register speak out well that there is risk. with which more than one note is down at the effect of a break by the cessation of the higher octave above that will be avoided. the Open 32, which at once gives that and the 16 do., and perhaps shakes the place. For still more draw the metal 16, which brings with it the loud 8ft. Principal. If more wanted add the 8ft. Flute, which of course brings the 4ft. with it. For yet more draw the Mixture, which at once gives VI. ranks. All this is independent of Reeds. The Posaune may be freely used, bringing the soft 16 with it: for a really powerful passage draw the Bombarde, which brings the 8ft. Reed also. Remember that the foregoing are all independent of combinations which may be made with the Super-octave in; and even here is ample choice thus, Violone alone or with Flute, or with Bourdon, or all three together, &c. g. With the three 32fts. here given not only will there be no temptation for the performer to break, but with the Bourdon the only 32ft. in use, the temptation will be positively not to do so, for this Stop not going below the bottom G, the notes below that will inevitably be slightly inferior: thus, in all Accompaniment of Voices the Bass will preferably be taken as it stands, for the Open or Reed 32 will not often be out. In regular Organ solos the Pedal obbli Pedal keys below GG, thus bringing the finest gato part will certainly give occasion for the notes or at least the largest of all into requisition. It need only be added that the 32ft. Posaune may easily, if desired, also stop at GGG. h. With the foregoing arrangement there will be, as already seen, two breaks. The first is caused by the cessation or "running out" of one or more 32ft. Stops at the G G or FFF Ped. Key: the second is referable to the Pipes not extending an entire octave above the top note of Ped.-Board. (Pedals to C C C are understood, remember.) The first break can never be offensive, for three reasons, as follows. When the Organ is accompanying voices the lowest Ped. G will not be passed sufficiently often to render the point in any way of importance. When (as for Classical Sonatas or Fugues) the Ped. Keys below G G are required, there will always be sufficient of the louder portion of the Pedaleas well as Manual to latter-to entirely veil the break. In any case the great depth of the entering or ceasing sound-G G G, or else one note lower-prevents any offensiveness, for it must be remembered that the 32ft. will never be used without the 16ft. accompanying it. The second break is palpable, but not offensive, for half the entire Pedal of course goes on unbroken. It may obviously be wholly got rid of by employing a complete extra octave of Pipes; but in practice it will be found that D will form the upper general boundary of the Pedal part, and that even this note is not often wanted. (To be continued) THE CARBON AND THE CROWN Z. Pedale Organ. It will be obvious at once that it is here that Borrowing is of the greatest value. The great size of the Pipes, the distance apart of the Sliders and Holes, the rarity time, the thickness of the Upper-boards in many cases, and the fewness of the Registers e. The second defect is still more serious. The (though this latter is, of course, a very great want of the upper Pipes to C has a tendency to defect in many Insts.)-all these things point strongly to the Pedale as the Section on which lead the Organist to break his Pedal passages so Borrowing may be not only advisable, but of as to keep the notes of good depth. This second very great value and I have no hesitation defect confirms the bad habit by rendering it whatever in saying that, except in cases where impossible that he shall get the depth without both room (room is saved here even with the it. To remedy here must be at least one 32ft. Stop: it does not in the least require to go horrowing by wind-this will be apparent on a below GGG, but one such Stop, and to such moment's reflection) and expense are really no objects whatever (and it is manifest that this point, is absolutely necessary; and as soon as latter can happen but rarely), it is simply un- Ped. is large enough there should be two such wise to refrain from giving the Pedals the ad- Stops, and again as still enlarged a third added vantage of a judicious and correct Borrowing.generally a Reed. The latter need not go It has, however, already been pointed out that below GGG, but it may be a rule that when Wind-borrowing should not be resorted to it is present one of the 32 Flues should. The except with the very greatest care; for if the pile, il not, the steht ugh if in any way I will be remembered that in the dispute as unborrowed Stop be quite on its wind, as is possible; if not, the Stopt either unbroken or to the invention of the microphone some generally and desirably the case, and the continued as a Quint. It must be borne in mind doubt existed as to the meaning of the word grooves or conveyances by which the borrow that the Pedale Stops should here be such that ing is effected be not of really ample size, the repetitions are avoided. A good Specification ing quotation that a different meaning attaches borrowed Stop will be liable to sound flat; for will run as thus:-Open Diap. wood, 32ft.; to the word in the United States than has the unborrowed will always be tuned true, and Metal, 16ft.; Violone wood, 16ft.; Flute, 8ft.; book on the telephone it is stated that "in Sub-Bourdon, 32ft. (to GGG only); Open Diap. usually been accepted here. In Mr. Prescott's when the pipes are sounded from the Dummy Grave Mixture, III ranks; Posaune (free), 32ft.; the latest form of transmitter which Mr. EdiSlide, if the" flush" be not very full indeed, the Bombarde, 16ft. The real Specification would son has introduced, the vibrating diaphragm is decreased supply must, as just said, cause thus stand as the foregoing, with the addition done away with altogether, it having been of the following:-Open Diap. wood, 16ft.; found that much better results are obtained [27, a.] For this reason it must be distinctly Bourdon, 16ft.; Principal, 8ft.; Violoncello, when a rigid plate of metal is substituted in understood that, except where a soft tone only 8ft.; Flute, 4ft.; Full Mixture, III ranks; its place. With the old vibrating diaphragm is desired, it is not on the Pedale recommended Fagotto, 16ft.; Bombarde, 8ft. the articulation produced in the receiver is to borrow by Wind. In such particular case, f. Now, the foregoing is not a really more or less muffled, owing to slight changes however, by plugging down the Pipes, and formidable affair. Only eight Stops, seven which the vibrating disc occasions in the pres taking care that both Dummy Slider holes and running 3 octaves, and one (the Bourdon) sure, and which probably results from tardy channels be ample, the l'ipe will receive by extending but 24, the 32ft. Open Diap. the only dampening of the vibrations after having been latter as much wind as it will take; and as, serious consideration. Yet it is manifest that once started. In the new arrangement, the owing to the plugging, it cannot ever use not only would it form a really splendid Pedale articulation is so clear and exceedingly well more than this, however large be the flush from of 16 Stops, but the manipulation would be much rendered that a whisper even may readily be its own Slider, the result will be a uniform pitch simplified, for by keeping the Super-octave transmitted and understood. flatness. "inflexible." It will be seen from the follow The inflexible plate, of course, merely serves, in consequence kettle or boiler with sufficient heat, and for a though it may be run up to it more quickly, if of its comparatively large area, to concentrate a con ilerable portion of the sonorous waves upon the small carbon disc or button; a much greater degree of pressure for any given effort on the part of the speaker is thus brought to bear on the disc than could be obtained if only its small surface were used." The engraving, Fig. 1, represents one of the later forms of telephone with the "inflexible" diaphragm. It consists essentially of a piece of prepared carbon, C, inserted in a ring of hard rubber or ebonite in such a manner that one surface is brought into contact with the very broad-headed metal screw forming part of the metallic frame of the apparatus. The other side of the carbon is covered with a circular piece of platinum foil, P, connected to a binding post insulated from the frame, and forming the other connection for putting the instrument into a circuit. Over the platinum foil, to which it is cemented, is a glass disc, G, carrying a knob of aluminium, against which the diaphragm presses slightly. When the instrument is spoken into, the variations of pressure are communicated to the carbon, and the electric undulations are accordingly set up in the now well-known manner. But the vibrating diaphragm, it will be seen, still exists. In Fig. 2 is seen the double crown telephone of Mr. Phelps. It contains two diaphragms, and in shape somewhat resembles a double crown, as shown in the figure. Twelve permanent magnets bent into a circular form are FIG sufficient length of time, to cause them to desired. It is kept at that temperature for about six hours, and then cooled. It is then heated to about 200° or 220° Fahr., when about 2lb. to 4lb. of sulphur is added, and the heat run up during about two hours, to, say, 550° Fahr., and kept there for about five hours. When cooled the mixture will be ready for mingling with the tar in the manner described. Linseed oil is also treated in a similar way, and may then be added to the mixture of cotton-seed oil and tar. Other vegetable oils, such as castor oil or olive oil, may be employed in this process, the heat at which they are tobe combined with the sulphur being adapted to the nature of the particular oil selected.. Castor oil requires a somewhat higher heat. than cotton-seed or linseed oil; but in each. case the proper temperature can be readily determined in practice. After the oils have been. thus treated the remainder of the process for completing the kerite should be in all respects the same as in the ordinary method of working above described, except that the proportion of sulphur employed for vulcanisation, after the oils have been combined with the resinous and other ingredients, should be lessened by as much as was used for the preparatory sulphurisation of the oils. It frequently happens, unless great watch- It will be seen that the distinctive feature fulness and care are used, that the action of of this part of the improvements is the partial the sulphur, when or after it begins to com- vulcanisation of the oils with a small proporbine with the oils, is so rapid as to produce a tion of sulphur at an extremely high temperasudden and very great increase in the temperature, as a preparation for combining them. with the other ingredients of the kerite compounds. By this means the kerite is greatly increased in tenacity and compactness, a more reliable elasticity is obtained, and in general a closer approach is made to the qualities of natural indiarubber. By his improved process the patentee is able to employ much larger proportion of kerite with the natural rubber than heretofore, a result of great importance in diminishing the cost of rubber fabrics. It may, however, well be doubted whether the use of oils, even when sulphurised, is altogether an improvement, if the compound is used for articles of wearing apparel, though it is probably well adapted for many waterproofing purposes, and for the preservation of substances liable to oxidation. used in place of the single magnet employed in ture, which is caused by the generation of MA KERITE OR ARTIFICIAL CAOUTCHOUC. every or almost every instance. Paraffin may ANY processes have been devised for the about 30lb. of cotton-seed oil of a good quality, ADVANCES IN TELEPHONY. FROM ROM a paragraph in the Echo we learn that "an engineer at Springfield, Connecticut, claims to have discovered a way to make the string telephone almost as effective as the telephone itself. He uses thin button iron in place of the membrane commonly used' in the twine telephones. Wire pins are made use of as hangers, to which are fastened small non-conductors of glass. With this simple apparatus it has been found possible to converse easily across the Connecticut River, which is nearly half a mile in breadth." It is true the telephone came in its developed state from the United States, but here we have a Yankee inventing something that had been almost forgotten in this country, though we believe neither Hook nor any of his imitators made use of small non-conductors of glass fastened to hangers, and it is indeed difficult to see what purpose they can serve, as in this case we presume there is no pretence that an electric current is present. The allusion to the Connecticut being nearly half a mile broad betrays a peculiar ignorance of the nature of the real telephone. If, however, the United States has retrograde inventors, we have many simple patentees in this country, who take up old ideas, and by putting them in a different way believe they have discovered something new. An officer in the Engineers has recently patented improvements in apparatus for taking up, sending, and repeating voice sounds by electricity to and from distant stations or places. According to this "invention," the voice acts as a regulator, and not as a source of power, whereby the strength of vibration of a metal disc, and the consequent loudness of articulate speech at the receiving station, are not limited by the strength of voice of the speaker at the sending station. The apparatus consists essentially of a plate or membrane, vibrating to the tones of the voice. This membrane or plate causes to be introduced |