sabject (unfortunately in a newspaper), I tried to interest astronomers in the matter by private correspondence. In this I failed, and I therefore determined to wait until after another spot maximum for fresh evidence before again bringing the matter up; but Prof. C. A. Young having recently published an article in which he refers to this connec Period of Observation. No. of Disturb ances at E limb. Magnets more or No Record. (See note.) 29 232 1885, July-1886, July... 49 17 10 312 Note." No record" means that the disturbance (if any) of the magnets at Toronto Observatory was not sufficient to be noticed by Mr. Carpmael in the short magnetic reviews which I consulted. view of convenient subdivision than with particu- first. is power in nature, namely, corn, coal, and falling water. In the first place, it will be obvious that, where electricity is the transmitting agent, we can effect the transmission both in the stored and in the live form. To see this clearly, we need only for a moment revert to our example of the coal pit and rediscovered) in the United States, I am compelled of power transmission, the one taking place over tion as having been recently discovered (or rather We have thus to distinguish between two kinds the mill. Instead of sending the coal to the mill to be converted into power there, we could burn it at to again refer to my work in this connection distances reckoned by feet or yards, and the other the pit, and thereby generate steam to be used for without further delay. over distances reckoned by thousands of feet, or driving a steam dynamo. The current from the This being merely a preliminary note, I will give even by miles. When we speak of the electric dynamo we could utilise in charging a storage my results for three years only. They are quite transmission of power, we tacitly assume that it battery, and send this to the mill, where it would sufficient, though, to show that there is a distinct connection between the visibility of solar disturb- belongs to the latter class, and refers to distances drive an electromotor, thus taking the place of the local steam-engine. Here we have a system of ances from the earth and terrestrial magnetism. beyond the reach of the ordinary gear, such as transmitting energy in the stored form. On the shafting, cogwheels, pulleys, and employed other result of a solar disturbance, when on the for the subdivision and distribution of power visible hemisphere, apparently has a greater effect within the walls of a factory: and it is in this as a vehicle of energy, and connect the dynamo at the pit with the motor at the mill by a on the earth's magnetism than when on the hemi- generally accepted sense that I propose to bring pair of insulated wires, we have a system of sphere turned away from our view. This discovery the subject mainly before you. There are, howwas originally made by finding on many occasions ever, cases where the application of electro-motors electric transmission of power in the live form. The an aurora following the appearance of large spots possible method of applying mechanical power to fore forms the principal subject of these lectures; to special tools is either the most convenient or only term "electric transmission of power," and therelatter system is that generally understood under the at the sun's east limb; but I soon found that solar disturbances of every size, when first seen at that the performance of certain operations, and it will, but before entering upon it, I propose briefly to limb, apparently caused a disturbance of the earth's therefore, be necessary, at least briefly, to glance magnetism. To illustrate this I will give the at that part of our subject which is not usually investigate the capabilities of electric transmission results for the period 1885, July-1888, July. I comprised within the title of these lectures of power in the stored form. namely, the transmission of power over very short As you all know, a sack of coal contains more have compared my observations of solar disturbances distances by means of electric currents. We thus stored power than a secondary battery of equal and auroræ during this period with the magnitude distinguish between "long-distance" and "short-weight, and its carriage, whether by rail or road, and auroral results published in the Monthly distance" transmission, the fundamental distinction is cheaper, easier, and requires less precautions than service kindly furnished for this purpose by transfer or transmission of power from one point there is no objection to the establishment of a steam Weather Review of the Canadian meteorological between the two being that, in the former, the that of the battery. It is, therefore, quite obvious that, if the primary source of power is coal, and if Mr. C. Carpmael, M.A., F.R.A.S. The accomto another, so to speak, in bulk is our main object; panying table shows the result of this comparison: whilst in the latter we rather aim at the subdivision engine at the place where the power is wanted, it and convenient application of power in small quan- the form of coal than in the form of batteries, not will be more economical to carry the power there in tities at various points, and for particular purposes. only because of the saving in carriage, but also on I propose to consider long-distance transmission account of the smaller capital outlay, the smaller depreciation, and the avoidance of the loss of energy in the battery itself. But let us assume that the primary source of energy is falling water, then it is not BO obvious at the first glance that its electric transmission in the stored form should be uneconomical. We cannot produce coal out of the energy of falling water, but we can charge batteries with it, and electricity would thus seem to offer a means of utilising a Power of nature which would otherwise be lost. It might, perhaps, here be objected that electricity does not form the only means for utilising such a power, since there are various other ways in which Power may be stored, a familiar example being compressed air. We might, therefore, also utilise the power of the waterfall for working an air compressor, and store the air under pressure in steel reservoirs, to be used afterwards for working air engines constructed similarly to ordinary steamengines. Many such engines are actually in use in Paris on the Popp system, though there the air is constorage vessels, as would be the case in our veyed to them by pipes under pressure, and not in example. There can thus be no doubt that the transmission of power by stored air is practicable; but the question is, at what cost will it be effected, The answer to these questions depends on two and can it compete with transmission by batteries? factors, namely, the storage efficiency and the cost of transport. By storage efficiency, I mean the paratus which serves as the vehicle for the power. ratio of the power put into and taken out of the ap Batteries may now be obtained in which this ratio The most important sources of power in nature is about 80 per cent.; that is to say, for every are corn, coal, and falling water. Under the term 100H.P. hours put into the battery, 80H.P. hours "corn" I comprise all vegetable food-stuffs suit- can be taken out. The storage efficiency of able for conversion into mechanical energy by compressed air is very much smaller. The most means of horses and other animal engines; whilst reliable data under this head are to be obthe term "coal" naturally includes all kinds of tained from the paper which Prof. Kennedy fuel suitable for conversion into mechanical energy read before the British Association in 1889, by some form of heat-engine. The power derived when he gave an account of experiments from corn and coal is generally transmitted in the carried out in Paris on the Popp system. He found stored form; that derived from falling water in the that the indicated efficiency with cold air was 39 live form, since the conveyance of water at a high per cent.; that is to say, for every 100H.P. indilevel, or under considerable pressure, to great dist-cated by the compressing-engine, 39H.P. were inances necessitates the erection of very costly works. dicated in the engine driven by compressed air as it To prevent misunderstanding, I must here point came from the mains. If the air before being adTHE ELECTRIC TRANSMISSION OF out that I use the term "stored energy" as applied mitted to the engine was heated to 320 F., the to water, merely in its colloquial sense. We speak apparent indicated efficiency rose to 54 per cent., of the energy stored in the water of a mill-pond, but, but as the heat energy thus supplied to the air reTHE HE transmission of power, in whatever way it in reality, the energy does not reside in the water quires the expenditure of fuel at the point where may be effected, is one of the most important at all, but is an effect of its elevated position, and the power is wanted, the use of hot air really problems in applied mechanics. Strictly speaking, is, therefore, not comparable with the energy involves two methods of transmission-namely, it enters into and is, indeed, precedent to the appli- which is chemically stored in coal. Leaving, how-that of power in the shape of air under pressure cation of power to all industrial operations. The ever, such distinctions on one side at present, we flowing through the mains, and that of power in power developed in a Lancashire mill-engine only may regard water, which is being carried along the stored form contained in the fuel. To make becomes of value to the spinner or weaver after it horizontally, at a certain elevation, from one place the comparison with electric transmission of has been transmitted to the mules or looms by the to another, as the vehicle of so much stored stored power a fair one, I must therefore take agency of ropes, belts, pulleys, and other gear. energy, which we can obtain, in its live form, at Without such gear effecting the transmission, any point at which we establish a water-engine, the power developed by the local steam-engine through which the water passes in its descent to a would be as useless to the mill-owner as the lower level. If we carry water along in this way, Dower which may be contained in a waterfall it is not with the object of bringing the stored les away. In either case transmission must power to the point of application, but merely to de the application of power; but whilst in the secure the largest possible fall, and, therefore, a case the problem of transmission is simple, maximum of power with a given quantity of water. to be attacked rather from the point of If it be necessary to transmit the power farther, the transmission is generally effected in the live form. Now let us see what power electricity occupies in relation to these primary sources of Broadly speaking, there are two ways in which we can transmit mechanical energy from one place to another. Let us assume, by way of example, that the primary source of energy is coal, and that the power derivable from this coal is required, not at the pit's mouth, but at a mill a certain number of miles away. In such a case, the obvious, and also the most economical, way of transmitting power is to carry the coal to the mill, and burn it under the boiler of the mill-engine. Even if the distance between the pit and the mill is short, this method will be the best, provided there are no difficulties of transport. Suppose, however, that, although the distance short, local conditions, such as a great difference of level, bad roads, or total absence of roads, render the carriage of coal difficult or impossible, then we would establish our boiler and engine at the pit, generate the power there, and transmit it by wire methods are essentially different. In the first case cases we have transmission of power, but the we have transmitted, not mechanical, energy itself; but the thing from which mechanical energy can be obtained, namely the coal, each ton of which represecond case we have transmitted the energy itself in sents so many stored horse-power hours. In the its kinetic or potential form. In popular language we might describe the process as the transmission of mission of "stored" power, which takes place power, as distinguished from the transwhen we carry coal from the pit's mouth to the mill. An inspection of the above table shows, I think, the connection very distinctly. It will be seen that on 65 of the 109 occasions when disturbances were at the sun's E. limb, an aurora is recorded on the same date. Of the remaining occasions the magnets at the Toronto Observatory were more or less dis-rope, or in some other way, to the mill. In both turbed on 38 dates. This leaves only six dates to be accounted for. A closer agreement could hardly be desired, especially when we remember that many of the solar disturbances in the list were quite small. After deducting from the list of aurora and magnetic disturbances those caused by a solar disturbance becoming visible at the sun's E. limb, I find many remain for explanation. I will deal with these at length in a future paper, and will only say here that many disturbances of the earth's magnetism can be traced to the breaking out of spots on the sun's visible hemisphere, and to sudden changes in the activity of a disturbance already visible. I would also say here that I find facula can even, when without neighbouring macula, affect the earth's magnetism. This being the case, I generally use the term "disturbance" in place of "spot." Faculæ, spots, prominences, &c., are, of course, merely theresults of a solar disturbance. This subject will also be referred to on a future occasion.VƏT GA Brantford, Canada, May 4. POWER.*. T KAPP. Extracted from the Cantor 1 before the Society of Arts.... "live" the efficiency of the Popp system when the air is not heated. A correction must, however, be made for loss of power in the mains. In the Popp system, the power is transmitted in the live form by air flowing through pipes, and there is necessarily a certain loss on account of friction in the pipes and valves. As far as the friction in the pipes is con cerned, this would not occur if the transmission were effected in the stored form by means of air carried under pressure in a reservoir; but, on the other hand, the loss by friction through valve would be greater, because it would be necessary to insert between the reservoir and the air-engine a reducing valve, which would regulate the supply of air as the pressure falls. The loss of power due to this circumstance will probably be greater than the corresponding loss in the Popp system, where the pressure is constant; but as I have no experimental data to determine this point, I take the same loss as found by Prof. Kennedy, namely 2 per cent., which makes the indicated efficiency nearly 40 per cent. The efficiency of the air-engine he found to be, with cold air, 67 per cent., making the total efficiency of the system 26-7 per cent. By adopting air storage we could, therefore, obtain 264H.P. hours for every 100H.P. hours indicated in the engine. Now let us see how the case stands with electrical storage. The efficiency of the steam dynamo, that is, the ratio of the electrical output to the indicated power, may be taken as 83 per cent., that of the batteries 80 per cent., and that of the motor at least 85 per cent.; so that the total efficiency works out to quite 56 per cent., or more than twice that of the rival system. I have here assumed that the dynamo is steam-driven, simply because the only reliable figures I could obtain about compressed air referred to steam-driven compressors, but it THE SCIENTIFIC NEWS. pedition will be in a position to start in about fifteen months' time-that is, about early summer in the regions round the South Pole. Lieut. Peary, of the U.S. navy, however, proposes to reach the North Pole by travelling through Greenland on foot; but perhaps the "Paleocrystic Ice" will stop him. There is much to pay the scientific explorers in those regions, and probably quite as much, if not more, in the Antarctic "cap." HE note by M. E. L.-Trouvelot, entitled "Phénomène Lumineux extraordinaire observé sur le Soleil," has been issued separately from the Comptes Rendus, and will doubtless be widely circulated. On June 17, 10h. 16m. Paris mean time, M. Trouvelot saw a luminous ontburst on the sun, which he says was apparently of the same character as that observed simul. taneously by Carrington and Hodgson on command of Herr Borchert, the late commander An expedition to the African lakes, under the September 1, 1859, and described in the Monthly of the rear-guard of the German Emin Pasha Notices, vol. xx. pp. 13-16. It was a luminous Expedition, is being organised. A geographer spot of a yellowish colour, near the western limb will be attached to the expedition, and Lake of the sun, and soon afterwards another appeared slightly north, from both of which what seemed Victoria will be sounded and its banks thoroughly explored. to be volcanic bombs were projected. The phenomena were observed on the next day, but not in such activity, and ceased to be noticed soon after noon on June 18. They do not seem to have been observed in this country. Dr. Berberich's ephemeris of Wolf's comet for is obvious that the comparison of the storage Berlin midnight on July 22 is: R.A. 1h. 47m. percha, or to anyone who has made any deserving efficiencies of the two systems cannot be materially affected by the source of power, and will practically be the same in the case under consideration, where the power is supposed to be derived from falling water. We see that in efficiency, at least, air storage is far behind electrical storage. Let us now inquire whether it is any better off in the other essential feature I have mentionednamely, in the cost of carriage. The information available under this head is tolerably reliable as regards batteries, but this is not the case as regards air stored under pressure. I know of no experiments made to determine accurately the weight of air reservoirs, and, in the absence of such data, I cannot do better than adopt the calculated figure given by Prof. Osborne Reynolds in one of his Cantor lectures delivered in 1888. According to this authority, the weight of the steel reservoir and air contained would amount to 3001b. for every horse-power hour so stored. Now the weight of a secondary battery filled with liquid, and provided with a tray and connections, all complete, does not exceed 1001b. per horse-power stored, that is, only one-third the weight of an equivalent air reservoir. We see, therefore, that as regards efficiency air storage is twice as bad, and as regards weight it is three times as bad as electric storage. Competition with, it is, under these circumstances, obviously impossible, and we may therefore say that if the transmission of power from the waterfall to a distant point has to be made in the stored form, electricity is the only agent which need be considered. 248., N. Dec. 28° 7-6, when the brightness will The death is announced of Dr. William Henry attention. Another old correspondent died on Monday, when Thomas Pallister Barkas, alderman of Newcastle-on-Tyne, passed away in his 73rd year. Although in early life a builder, Mr. Barkas will be best remembered in his native town as a bookseller and as director of the Art Gallery. He was an indefatigable lecturer, and was the first to introduce the study of phonography into the North of England. An almost all-round student of scientific subjects, it was mainly as a palaeontologist in connection with the fossil fauna of the carboniferous strata that Coal Measure Paleontology," with an atlas of Mr. Barkas made his mark, and his "Manual of 247 illustrations, is a storehouse of information on the subject, for Mr. Barkas not only searched the colliery heaps himself, but induced the men and boys of the various collieries in Northumberland and Durham to send him any specimens they found. Many of them were illustrated in our columns some years ago. The Société d'Encouragement pour l'Industrie Nationale, of Paris, has offered two prizes for 1893, the first of which, 3,000fr., will be awarded to anyone discovering a substance partially if not wholly taking the place of guttacontribution to the knowledge of the planting, acclimatisation, or improvement in the culture of the guttapercha tree. The second prize of 2,000fr. is for the best apparatus or industrial method by means of which the insulation of the different parts of an electrical plant can be measured while the full strength of the current is passing. Further particulars can be obtained from the secretary of the society, 44 Rue de Rennes, Paris, before December 1, 1892. Communications should preferably be in French. attractive" exhibits in shop-windows is growThe use of electrical appliances for making ing, and as the electric light becomes more widely utilised they will multiply. In New York, at the Singer Co.'s place on Broadway, a "cabinet" sewing machine opens its doors at intervals, the folding leaf turns over, then the machine itself appears from its recess, and finally turns upon its side, showing the working of all parts under its base. The steps in the movement are retraced in the same manner, and the machine comes to rest and is closed, to go through the cycle of operations again. It is an advertising novelty, as the power cannot be seen or traced. in Edinburgh under the auspices of the Society An interesting heraldic exhibition is being held of Antiquaries, and will remain open until the end of August. It may be said there is not much science in "heraldry"; but as science is only knowledge, some acquaintance with heraldry is often of great value in settling moot points in archæology. Whether it would pay so to transmit power is a question which cannot be answered off-hand. As compared with the direct transmission of live power by means of a pair of wires, the cartage of batteries up and down the country will no doubt appear to be a clumsy device; but when we are investigating the different possible solutions of an important problem, we must not allow any preconceived opinions of what is elegant or clumsy to influence our judgement; we must, in fact, judge each case on its own merits, and I propose to deal with the electric transmission of stored energy in this sense. The system of power transmission by storage batteries is actually in use-not, indeed, for long distance transmission pure and simple, as above defined, but still for transmission over distances reckoned by pelled him to do something else, and a study of/runner mills under a moderate heat. storage batteries, which are charged at a central made his name famous amongst yachtsmen all and filled into metallic cartridges of various Ammonite is the name of a new explosive which is said to be especially adapted for mining purposes, as it is alleged to be perfectly safe under all conditions likely to arise. The comThe death is announced of Mr. Edward Burgess, pound consists of pure ammonium nitrate and the famous yacht-designer of Boston, Massa-nitro-naphthaline, both of which substances are chusetts, in which state he was born in 1848, combination they form a highly explosive comin themselves inexplosive, but in intimate At one time Mr. Burgess's special study was entomology, of which science he was instructor at Pound. The ingredients are dried and separately Harvard College; but financial reverses comground, and are afterwards incorporated in edge over the world. M. Rodolphe Koepplin, & distinguished chemist, who filled for many years the chair of physics and natural history in his native town of Colmar, died the other day in his 81st year. depot, and run for many miles before they require (To be continued.) The following statements as to the danger of using arsenic for preserving plants must be taken with all reserve:-The danger of using arsenical preparations for the poisoning of plants is illustrated by the fact that Dr. B. L. Robinson, assistant in the Gray Herbarium, Cambridge, THE greatest known depth of the ocean in the U.S.A., has been compelled to resign his position Pacific is near the Ladrone Islands, where sound- owing to ill-health resulting from this cause. It ings were made to the depth of 26,850ft., or a little is stated that the poisoning of plants has now over five miles. In the Atlantic the greatest depth been entirely abandoned in the herbarium; the found is just north of the West Indian Islands, tightness of the cases, and constant handling of which is 23,250ft., or nearly four and a half the sheets being relied on to preserve the specimiles. In those parts of the ocean most free from mens. If arsenic is dangerous, what must be the islands, as in the route from Newfoundland to Ire-risk when corrosive sublimate is used? land, the ocean is most shallow, seldom exceeding 12,000ft. The sizes, which effectually protect it from the absorption of moisture. be lost to the British coal trade, as the mines in It is stated that the German market will soon that country are being opened up rapidly. An official report on the smokeless powder tests made at Springfield, Massachusetts, has been published, and it appears that good results is wanted for firing shots in mines is, however, a were obtained with the Maxim powder. What flameless explosive. To obviate the waste of steam in steam-hammers, an improvement has been introduced in fitting the hammers with two pistons of different diameterscompounding them, in fact. CALIFORNIA'S production of quicksilver for 1889 was 26,464 flasks, equalling 2,024,496lb. This State has eleven productive mines of this commodity, which necessitates the employment of thirty-six furnaces, which, together with the mines, furnish work for 937 hands. A flask of quicksilver is produced at a cost of 33-31dols. The world's production of this article during the past decade is 1,093,611 flasks, the United States producing more of this amount that any other one country on the It is expected that the proposed Antarctic ex-globe. LETTERS TO THE EDITOR. [We do not hold ourse'ves responsible for the opinions of our correspondents. The Editor respectfully requests that all communications should be drawn up as briefly as possible.] All communications should be addressed to the EDITOR of the ENGLISH MECHANIC, 332, Strand, W.C. All Cheques and Post-office Orders to be made payable to J. PASSMORE EDWARDS. • In order to facilitate reference, Correspondents, when speaking of any letter previously inserted, will oblige by mentioning the number of the Letter, as well as the page on which it appears. "I would have everyone write what he knows, and as much as he knows, but no more; and that not in this only, but in all other subjects: For such a person may have some particular knowledge and experience of the nature of such a person or such a fountain, that as to other things, knows no more than what everybody does, and yet, to keep a clutter with this little pittance of his, will undertake to write the whole body of physicks, a vice from whence great inconveniences derive their original." -Montaigne's Essays. THE BRITISH ASTRONOMICAL ASSOCIATION. [32511.]-JUST a year ago you inserted in your columns a letter from Mr. W. H. S. Monck, advocating the formation of an astronomical association on somewhat more popular lines than those of the Royal Astronomical Society, and with its headquarters in London instead of in Liverpool, as had been the case with the Liverpool Astronomical Society. That suggestion, being warmly adopted in many influential quarters, bore fruit in the formation of the British Astronomical Association, and I have thought it might be of interest to your readers if I gave a brief summary of our first year's work. In these twelve months we have chosen our first president, officers, and council, organised our business, appointed eleven directors of observing sections, some of which have been in very vigorous activity for several months, and others, though more recently formed, will doubtless soon have a good record to show. We have held one business, and eight ordinary meetings. All have been interesting, all well attended, and most have even been crowded. [32512.] DR. KLEIBER'S computations are very highly-painted one. First, Mr. Pope says, "My electric clock is free from all these objections and misfortunes, for the simple reason that it is an independent clock." This is not new. Fifty-one years ago, Prof. Wheatstone built an independent clock. Secondly, Mr. Pope talks about "an entirely new and ingenious mechanism, constructed on the principle of the detached lever." Is Mr. Pope quite sure that detached lever is new? Absolute intervals of time are marked, no matter whether the amplitude of the pendulum be more or less. For Mr. Pope's information, may I remind him there is already in the market (I hope I am not advertising) a clock with a pendulum, the bob of which may be 21b., 3lb., or 4lb., or any reasonable weight; may be lowered lin. or 2in. or raised lin. or 2in. without altering time-keeping.. "Glatton Bays Mr. Pope gives no information beyond the fact that he sells electric clocks; we may expect to see shortly in the advertisement column an announcement running thus:-" Electric clocks. Accurate time-keepers. Polished cases, with battery, complete. Warranted to go twelve months without stopping. Price 4s. 6d., post free." This is about the price of the small Yankee clocks now on the market, but these want winding every twenty-four hours, or oftener. an electric clock as cheap and as reliable as Mr. However, if anyone can put on the market Pope would have us believe his is, a very large fortune must soon be made. G. W. A. F., Electric Clock Maker. MALT WORTS. " [32516.]-MR. J. A. WILSON makes a slight mistake with regard to the Stockport brewing case (letter 32484). If he reads the analyst's evidence carefully, he will find that the prosecution was for adding sugar,' no mention of the kind being made. After the lapse of a few hours from the time the yeast was added to the wort, any cane sugar that might have been present would be inverted, but in case inversion had not taken place it would be estimated as glucose, and not as cane sugar. Though the shifting of the radiant continues, according to Mr. Denning, until about the 22nd of August, and the final position is at, or near, the point 78° 56°, the last position to which the name Perseids" is appended in his table is at 60° + 59° on the 16th of August, the first being at 3° + 49° on the 8th of July. Comparing these two extremes, I find a difference of 5-6 in the value of i and of 19.4° in the value of - 8. And in both cases I find close approaches to the values both of i and of π – in radiants not styled "Perseids" by Mr. Denning than in those so designated by him. THE ADDITION OF CANE SUGAR TO The nearest approach to the radiant at 3° + 49° on July 8 is one at 21° + 57°, on July 29, the difference being only 1-6° in inclination and 1.3° in the value of ; and the nearest approach to the radiant at 60° 59° on August 16 is one at 70+ 66°, on August 22, the difference in inclination being only 0-1, while that in the element π- is 2.6°. A radiant at 40° + 56° on August 3, however, approaches almost equally close to that at 60° 59° on the 16th. Dr. Kleiber has evidently merely examined whether the radiants which Mr. Denning calls" Perseids" would fall in with the ring theory, which he thinks they do tolerably well. But if, discarding Mr. Denning's appellations, he had selected from the catalogue the positions which accorded best with the hypothesis of a ring, I think he would have rejected some of Mr. Denning's Perseid positions, and inserted some of those not so designated, with the result of a different law of shifting and a different duration of the shower. For instance, the radiant at 3+ 49° on the 8th of July is in close agreement (as regards the elements with one at 299° 24° on the 20th of April, one at 7° 53° on the 17th of July, and two at 18° 58°, and 21° 57° on the 28th and 29th of July respectively. July 10th. As to our membership, though this time last year the very idea of the Association had scarcely taken shape, to-day we number no fewer than 586 members, the great majority of whom, as accords with our title, are residents in the British Isles or in the Colonies, but a sufficient proportion are foreigners to prove that our venture has been looked upon with very friendly eyes by astronomers abroad. Ini and T England we find only five of the very smallest counties unrepresented on our roll, whilst Scotland, Ireland, Wales, and the Isle of Man all contribute in fair proportion. Cape Colony and Natal supply ten members already, Australia seventeen-the forerunners, we trust, of vigorous branches to be started in those colonies before very long, and several other portions of the empire are also represented. We have issued eight numbers of our journal, 474 pages royal octavo, which have been generally well received, and trust to issue two more numbers before the commencement of our next session. We have so far paid our way, with a balance in hand, and this in spite of the lowness of the subscription and the considerable size of the journal. I think, therefore, that we may fairly congratulate ourselves upon having made a successful start, and the prospect for the future appears to be a bright one. And of this success it is but bare justice to say no inconsiderable portion is due to the help you have yourself extended to us by the publicity you gave to the preliminary stages in the formation of the association, and the full reports you have so readily published of our meetings. We have not yet fulfilled all the details of our original programme, notably the purpose of holding meetings otherwise than in London. But it is yet early days with us, and in due time we may hope to accomplish this and much beside. At present fully one-third of our members reside in or conveniently near to London, whilst no other town, no county even beyond the home counties, contains sufficient members to render the success of a meeting probable. This will, however, no doubt come in time. If the marvellously rapid and sustained growth which these last months have witnessed be kept up, as there is already solid reason to believe will be the case, it will soon be time to try the experiment in one or more of the great provincial centres. One word more. The fear was expressed in some quarters when the Association was started that its success would mean injury to the older and the far more important body, the Royal Astronomical Society. Those who were most active in the initiation of the Association believed, on the other hand, that the more successful it became the more it would strengthen the senior society. And it has proved so. Of 32 members who have joined the R.A.S. since the formation of the B.A.A., short as that time has been, no fewer than 14 had previously joined the Association. I believe that W. H. S. Monck. ASTRONOMICAL. [32513.]-YOUR astronomical readers who are interested in the meteoric branch of astronomy will do valuable work by recording all the shooting stars, both small and large, that they may be fortunate in seeing from the present time to the latter part of August. The writer will be glad to receive such a list of observations, with the intention of them being included in a discussion as to the character of the radiation of these bodies at this season of the year in and around Cassiopeia, the east of Ursa Major, and Perseus, with the hope of settling the question of the alleged shifting nature or stationary character of the radiant area or areas in this region of the heavens. It may be advisable to mention that we require the G.M.T. (approximate) of the observation; the magnitude of the meteor, estimated according to the magnitude of the stars; the places of appearance and disappearance; the duration-that is, whether slow, swift, or very swift, and remarks as to streaks or trains. 70, North-street, Leeds. David Booth. With regard to letter 32498, it is a pity that Dr. Sykes cannot write without showing so much professional animosity, especially when he knows 80 little of the subject, as is evidenced by the mistakes he makes in his short letter. In Mr. Hooper's book on brewing nothing is said about estimation of cane sugar under the head of "Analytical Examination of a Wort." If any method be given elsewhere, it applies only to pure cane-sugar solutions. But supposing, for the sake of argument, that the 1.56 per cent. of sugar mentioned in the Stockport case was cane sugar, that gives over 7 per cent. on the malt, & figure which, according to his own showing, is beyond, and not "just within the limits of probability." It is no wonder that Dr. Sykes would not like to swear to per cent. of cane sugar in a wort after showing so plainly as he does in his letter that he does not know how to estimate it at all. As to the "invidious" position the Somerset House authorities occupy, it is rather an enviable one than otherwise, and no doubt Dr. Sykes would like to share it. A certificate of analysis of a disputed food sample from them has never yet been found to be incorrect in a court of law, so I fail to see the applicability of the jealous sneer with which he closes his letter. Imperitus. THE HARMONOGRAPH. [32517.]-THE harmonograph has been menI have succeeded in tioned lately in your pages. getting some beautiful designs from my home-made toy. There is an illustration in Ganot's "Physies," showing how exactly similar results are obtained by a ray of light reflected on to a blackboard from two tuning-forks vibrating in harmony. I should like to ask some of our photographic readers if it is a camera, and THE ASTRONOMICAL TRADITION OF not possible to catch this ray in secure the very interesting results as a photograph F. G. S. STONEHENGE. [32514.]-I AM indebted to you, Sir, as always, for much courtesy and for your kind insertion of my communication respecting Stenehenge, including the photograph I sent for your inspection. As it is quite impossible to reproduce by any copying process the faint blush marking the actual point of coming sunrise, as given in the original, I should like to be allowed to say that Mr. Thos. B. Howe, Photographer, of Newbury, has copies to dispose of for a very reasonable sum, and they are certainly most clever and careful representations of the phenomenon. Newbury. J. M. Bacon. ELECTRIC CLOCK. [32515.]-I QUITE agree with "Glatton," in your issue of the 3rd inst., as to letter 32416, being an advertisement in disguise; and not only so, but a NAPOLEON THE FIRST'S BEDSTEAD. ENGLISH MECHANIC AND WORLD OF SCIENCE: No. 1873. THE KINETOGRAPH. [32519.]-Ir is noteworthy that so long ago as eleven years, Mr. J. A. Rudge, of Bath, had constructed a lantern for projecting a series of pictures on a screen, with the object of giving them a lifelike appearance. He claims, or his nephew claims on his behalf, to have been the first to conceive and make a practical apparatus, exactly identical with the lantern figured on page 356, ENGLISH MECHANIC, June 19th. Mr. Rudge does not inform your readers if he has succeeded in making any improvements on the form of lantern described. If he has not done so, I will venture to say a lantern constructed in such a manner would be so cumbrous and costly that it could never become popular or successful. To produce anything like a satisfactory effect, the circle of picture should not be less than 50, for which fifty sets of lenses would be required for each lantern, and a similar number for each camera. In the Zoegraphoscope, which I briefly described in my letter of June 19th, the same effect is produced by one set of lenses only, the camera and lantern being in combination-a factor of the utmost importance from a commercial point of view. Mr. Eldridge, in letter 32480, relates how he also conceived the idea of the kinetograph eight years ago (apparently three years behind time), and like another James Watt, it was the kettle on the hearth, or rather the teapot on the hob, that brought the inspiration, and a sudden flash in the brain-pan, or from the brown earthenware, solved the problem once and for all. The idea "to convey by powerful reflectors from mirrors by electric wires news of various scenes to audiences in various rooms" is a very good one, no doubt, and almost out-Edison's Edison, but it is not the kinetograph, nor is it yet within the range of possible, or rather probable, physics. Seeing by electricity, like photography in natural colours, has been for many years the dream of the physicist, and who can say that these entrancing dreams may not in future years be realised? In the meantime there seems evidence enough that the depicting of moving objects on a screen with lifelike effects, can be successfully accomplished, and will form a valuable adjunct to ordinary lantern exhibitions. Plymouth. Jebus Bickle. A COLOSSAL DYNAMO. [32520.]-Your readers seem so much interested in dynamos that they will probably like to have a few particulars of what is believed to be the largest in the world, recently constructed for the Willson Aluminium Co., of New York. The machine is unusual, not only in size, but in general construction. The frame of the machine consists of two enormous castings with salient pole-pieces having wrought-iron cores, both above and below the armature. The armature itself is 24in. in diameter and 47in. long, and is of the Gramme construction, formed upon a 5in. hammered steel shaft resting in composition bearings 15in. long. The armature alone without the pulley weighs 6,163lb., while the frame contains 11,000lb. of castings and 7,000lb. of solid forgings. As the machine stands with its present pulley it weighs a little less than 30,000lb. rather singular that this phenomenally large machine T. Johns. letter 32501, that wind power is cheap, providing H. Morgan. THE COST OF ELECTRIC LIGHTING. JULY 17, 1891, under an extremely low load factor, and by the are depleted by their machinery and mains working very expensive superintendence necessary to keep everything going properly. In time the mains will give a better return on the capital expended on them, and the central stations will have become so intendence will be reduced. There is every hope well organised that both the labour and the superthat some day the electric light will not be much dearer than gas is now, but we entirely deny that we have already reached that stage in London. The above figures do not exactly tally with those are words that puzzle. Surely it costs more than given by Mr. Fletcher (1d. in the unit equal ls, in actual cost of the production of current is so little" the 1,000 of gas), but they are near enough. "The panies are satisfied with something less than 12 per cent! gas-or, rather, than gas need cost-when com Incans. issue, with respect to the cost of electric lighting, "Is there not one reader of the ENGLISH MECHANIC [32523.]-"INCANS" asks in your last week's Of course there are many! The photometric value who can give definite information on the subject?" of one unit of electricity is equal to 100ft. of gas. Taking it, light for light, it is, of course, dearer than gas at anything less than 38. 4d. per 1,000ft. In gas-making the whole of the work is done by The reason electricity is so dear is the cost of the labour, not only in the manufacture of the machines, but in the running of them permanently. light station you will find any number of welllabourers under skilled foremen; but in an electri dressed men, nearly all of whom are quite above soiling their hands by doing anything so low as work. C tram work. I remember seeing an electric locomotive coupled on to a car that was doing regular As with lighting stations, so it is with electric work, by four gentlemen in cuffs and collars. I also remember on a telpher line, not a hundred miles from London, that one Saturday the bottom of the electric locomotive fell out, and it took the united efforts of four of these cuff and collar electricians, one working foreman, and one navvy to fix it in its place again by means of a rope. 五碗 The idea among electricians seems to be that two manager, or employer. It is to be regretted that fitters will support one solution of the ancient problem-what to do with this is not the case, for there would be at onces clerk, draughtsman, our boys. electricians, men who hold certificates from this school or that college; but give them a file or The business is glutted with highly-educated hammer, and it will take a large certificate for them to hide their incompetency behind. A Mechanic. WHY ETHER? [32524.]-"F.R.A.S." (32492, p. 430) wants to the cost of gas was 18s. per burner per annum, and motion in the ether," Mr. Preece tells us that at the General Post Office indicating "the direction of the earth's orbital know why Dr. Lodge describes an apparatus as that when this was replaced by electricity the ex-dropping of water-the" line upon line, here a little instead of in space. Of The feature of this dynamo is the armature. It generated on the premises, and can be supplied and there a little" mode of impressing people. A pense only rose to 22s. per lamp. The current is course he knows the old saying about the constant is a Gramme ring with armature conductors very cheaply. It is well known that electricity can quotation from an article by Mr. Oliver Heaviside formed of solid drawn copper, with a cross section be produced to supply a steady constant demand at Electrician, July 3rd) may explain the purpose of bolted in place and insulated from each other, but rent, interest, depreciation, labour, fuel, and profit So it will be with the modern view of the ether of 38q.in.; the bars upon the periphery are rigidly 2d. per B. O. T. unit, and that this price will pay the continual iteration of the ether. no attempt whatever is made to insulate the surfaces; in fact, the brushes are made to bear being supplied at 44d. per unit, with a discount of as the medium through which energy is being sent on the generating plant. At Newcastle users are "He goes by faith, having taken it when young. directly upon it, thus forming a gigantic commutator 20 per cent. when their consumption is large. when a wire supports a current. Only train up the of the outer conductors of the armature. This Now, although the Post Office lighting is not so young to believe this, and they will afterwards look enables a large number of massive brushes (14) to steady as the driving of a mill, yet it extends over upon the notion of its going through the conductor bear firmly upon the conductors and take off a a great number of hours; practically all the lights as perfectly absurd, and will wonder how anyons current so great that it could hardly be handled come on at the same time and go off at the same otherwise. The brushes are distributed along the time, and the plant works at the highest possible length of the armature in neutral space, and are all efficiency. There certainly is no reason why the ride or drive a shying horse, and would (in the ever could have believed it." separately movable and adjustable. The insulation current should cost more than 34d., which is the interim of taking the best course-getting rid of No doubt "F.R.A.S." has occasionally had to used is asbestos and mica-the latter exclusively where equivalent of gas at 2s. 11d., and the figures given the horse) adopt the second-best course of leading the brushes bear and it will thus be seen that the bear out this idea. They also show that if under the creature up to anything he did not like, and armature is practically fireproof; at least, it is not such exceedingly favourable circumstances electri- making him look at it, and impress his mind with likely to be damaged by currents any less than city is more expensive than gas by 22 per cent., the notion that it was really nothing to object to. those sufficient to melt the massive bars. The then when it is retailed at 74d., it will exceed it by That is what the ethereal theorists are doing: they pulley that drives the armature is 36in. in diameter 250 per cent. Careful people will doubtless be able perpetually drag in the ether, whether it is wanted by 26in. face; but during a trial it appeared that to reduce the charge very greatly, but that is or not, to accustom people to accepting the word this pulley was of small diameter, and consequently equally true of all other domestic expenses. We (and by-and-by the idea connected to it) as matters the machine as used will have a 5ft. pulley. have grown used to a lavish amount of artificial of course. During this trial the machine, with its field light, and it is a great deprivation to have it separately excited, gave 25 volts at 130 revolutions, stinted. Most people would prefer a liberal use of and consequently would generate 110 volts at less gas, with all its demerits, to a poor illumination by than 550 turns per minute. ampères is very great, as may be imagined from the The capacity in electricity. great size of the conductors, and the designer estimates that the machine will rise to an output of 750,000 watts if necessary. During the test recently made no heavy current was drawn from the machine; but when running on open circuit the heating of the armature was so slight as to render it evident that Foucault currents and hysteresis were not formidable factors in its general efficiency. Later, when an adequate load can be secured, the dynamo will be put to a more thorough of the electric lamp as "the poor man's light," we Although we demur from Mr. Preece's definition do not deny that it may become so eventually. The actual cost of the production of current is so little that there is hope of the charge to the consumer being reduced in time. If 41d. is a paying price in Newcastle, it is quite certain that the same charge may be eventually attained in towns farther south. We know that coal is cheap on the Tyne, but the price of fuel is a very small factor in the expenses of the supply companies. Their revenues Sigma. COLOUR PHOTOGRAPHS. beautiful tints and colours of nature over the ordibeauty of a photograph to which is given the nary silver print, no matter how perfect a pr [32525.]-THERE can be but one opinion on the duction. plates, in my mind, almost solved the difficulty that had hitherto prevailed of easily producing the tit The introduction without the aid of an artist, and I have wondere of orthochromati much that scientific photographers have not sought by their aid to reproduce the colour and tints nature; but, like many others who follow photo graphy more or less as amateurs, I waited in vai |