1873 9,064 9,250 9,194 1874 2,193 ... we have to endure an increasing number of failures which will not reach its maximum until the fourth quarter of 1879." JOHN KEMP AND CO. Since this was written I have had counted the number of failures gazetted since January 1, 1878, and I find that they are 2,042 in excess of the corresponding period (January 1 to November 19) in the preceding year. Strange Properties of Matter J. K. THE following are two experiments which will, perhaps interest some of your readers: 10,848 Experiment No. 1.- The "Welding" of Metals at Low Tem- Some time ago, in order to estimate the amount of 122,260 hydrocyanic acid in a solution, I precipitated it with silver nitrate. After having filtered and washed the precipitate, I reduced it to the metallic state by heating to the required temperature. Just as I was about to allow it to cool, I noticed a small piece of dirt among the reduced silver. In order to separate them, I took a thin platinum wire, and pushed the silver to one side, but on attempting to take the wire away the silver remained in contact with it. As I thought this curious, I tried the following experiment. I took a piece of silver foil about one centimetre square, placed it in an inverted porcelain crucible lid, and heated it to about 500° C.; then I brought into contact with it the extremity of a thin platinum wire, and to my astonishment the wire raised the silver from the lid, and it remained in contact when cold, as the silver was so very much below its melting-point; the above fact caused me some surprise, and I could not satisfactorily account for it. "The question occurs: Does the number of failures in a year de pend upon natural causes? that is to say, Would the number rise and fall periodically according to the state of trade (or national prosperity) if the Bankruptcy Law remained constant? Whenever failures have become frequent, complaints have been made against the Law, and not without reason, but many who complain ignore the existence of any other cause. We compared the foregoing figures with the scientific tables recently published in NATURE, from the pen of Prof. Balfour Stewart, and, being struck with the coincidence in their fluctuations, we further compared them with the statistics published by Messrs. Dun and Co., of New York, of the failures in the United States during the past eight years, which period, being that of the existence of our present Bankruptcy Law, affords us a fair opportunity for making a comparison. Messrs. Dun and Co. report the following as the total failures in the United States during this period: 1870, Number of Failures, 3,551 "Evidently the same causes which were at work in England to depress trade and overwhelm the struggling and improvident classes, were equally effective in other countries-similar complaints of depression come to us from every part of the globe. "The discussion which has arisen out of Dr. Hunter's sugges. tion of a 'famine period' in India, has brought to the public some knowledge of the existence of natural periods or cycles, of an average duration of 119 years each. The suggestion that England is affected with the same regularity is but reasonable, and although fortunately for us as a nation the effects do not produce famine, it appears evident that some degree of suffering is caused, and that the number of failures is thereby materially increased the commercial panies which have occurred with about the same regularity furnish further evidence that this is the case. "If we make due allowance for the excessive number in the last quarter of 1869, caused by the change in the Law, we find that the maximum number of failures in the last cycle occurred in the year 1868, which was the year succeeding the natural minimum; hence we may conclude that about a year is required for the full effect of the natural depression to be reproduced in The twelve months from October 1, 1867, to September 30, 1868, appear to have been more serious to commercial men than either of the complete years, according to the number Vide NATURE, vol. xvi. pp. 9, 26, 45. 2 Messrs. Dun and Co.'s Annual Circular, January, 1878. I wrote to Sir W. Thomson, F.R.S., giving him a description of the above experiment, and in return I received a reply asking me to come and show him the experiment at his laboratory. I accordingly went up to the Glasgow University, and repeated it before him. He was very much interested, and advised me to write to NATURE, giving a description of the experiments. Sir W. Thomson gave the following explanation-That it was a remarkable case of "cohesion," the two metals, in fact, "welding," although the temperature was far below the melting-point of silver. The above experiment can be performed successfully at lower temperatures than 500o C., if smaller pieces of foil are taken. Other metals, for instance, copper and aluminium, cohere to silver in the same manner as platinum, but less strikingly. Experiment No. 2.-A Curious Resonator Some months ago I made the following experiment :-I took a small tuning-fork and struck it on the table. After the note had died away, so that it was no longer audible, I held the fork in the tip of the flame of a Bunsen burner, when the note was given out, so that it could be heard at some distance. I showed Sir W. Thomson this experiment, who gave the following explanation-That owing to the difference in density of the gases in the flame, the flame acted as a resonator, and so the note was emitted. It seems to me that experiment No. I could be made the subject of an interesting research, but as I am wholly engaged in commercial pursuits, I an unable to take it up. Glasgow, November 12 CHARLES A. FAWSITT Galvanometer for Strong. Currents I MUST confess that I was surprised by Mr. R. E. Baynes' communication, in NATURE, vol. xix. p. 33, that the galvanometer I have proposed in NATURE, vol. xviii. p. 707, has already been described. Before writing my article I have searched a good many books and journals relating to the subject without finding an allusion to any such instrument. Since Mr. Baynes drew my attention to "The Elements of Physical Manipulation," by Prof. Pickering, of the Massachusetts Institute of Technology, U.S., I have procured this book and find that it certainly does contain the theory of a galvanometer like mine, with the coil moving round a horizontal axis. As far as I know, such an instrument has, however, not been practically employed either in this country or on the Continent before I introduced it, though its want must have been much felt for some time past. This seems to show that Prof. Pickering's description of the instrument has not been brought to the general knowledge of electricians. If, therefore, my article in NATURE, at a time when electric currents of great strength are being so widely introduced into practical working, has contributed to make electricians acquainted with this form of galvanometer, I shall not regret the time I have spent in theoretically and experimentally investigating this subject. Prof. Pickering alludes in his book to the improper dip motions of the needle as a defect in his form of galvanometer; I think I have obviated this by pivoting the axis of the needle at both ends. Since communicating the results obtained with my experimental instrument, more elaborate instruments have been constructed and found very useful in many instances where the ordinary forms of galvanometers would not have answered the purpose. Woolwich, November 19 EUGEN OBACH Utilisation of the African Elephant I have just read some remarks in NATURE (vol. xix. p. 54) on the utilisation of the African elephant, which I think are worth considering. Judging from the specimens in the Regent's Park Gardens, which I suppose have not been selected in any way, and are therefore only average samples of the African species, I should say that the African elephant would prove hardier and capable of more work than the general run of Indian elephants. I was surprised to find that the two African elephants I saw in the Regent's Park were what the mahouts call "Dohara Band," which I would translate "double constitution." I do not think that more than five per cent. of Indian elephants are placed in this class. It is very rare indeed to see an elephant of this class in a Government Feelkanah, or in the hands of any European, because wealthy natives value them so highly and give such enormous prices for them, that even when caught by a Government keddah officer they are often sold on account of the fancy prices they fetch. The "Dohara Band" elephant will do a wonderful amount of work on a small quantity of food, and stands fatigue and exposure to the sun far better than any other sort. To commence elephant-catching operations in Africa, six "koonkies," i e., elephants trained for catching purposes, would be required, and about twenty men from Assam or some other jungle district of Bengal would be sufficient. With this establishment it would be possible to catch and train at least two hundred elephants in the course of twelve months. OUR ASTRONOMICAL COLUMN ORBITS OF BINARY STARS. In a communication to The Observatory, Dr. Doberck, of Col. Cooper's Observatory, Markree Castle, has summarised the results of the investigations on the orbits of the revolving double stars which have occupied him between three and four years, and which he has conducted with so much skill and laborious application. In a climate where the skies are too irregularly favourable to allow of an astronomer occupying himself wholly upon observations, it would be difficult to name any more interesting work to which he could devote his leisure, than such a revision of the elements of the binary systems. Dr. Doberck's account of his methods in different cases will be of much service to any one who may engage upon similar researches. He has found no reason to detract from the value of the early, graphical method of Sir John Herschel; on the contrary, instances are mentioned where it has been of the greatest service in tracing out the general form of the orbit, for correction by more refined processes, as in the difficult case of 2 1768: indeed, Dr. Doberck considers it superior to the second method given by Herschel from its admitting of the weights being approximately taken into account with ease. In a provisional orbit for the close double star 2 3121, the period assigned is thirty-seven years; at present we know of only two more rapid binaries. Some of the orbits included in Dr. Doberck's paper, have been made the subject of communications to the Royal Irish Academy, and have been published in the Transactions. In examining the question of variability of any of Lalande's stars, Mr. Gore will find it necessary, in the first instance, to have recourse to the original observations as printed in the "Histoire Céleste," there being many errors in the reduced catalogue. Thus, No. 5,499 appears through a misprint at p. 246, where the transit at the third wire is given as 2h. 47m. 45'2s., instead of 2h. 42m. 45'2s. The star is really No. 788 of Weisse's Bessel. The following star is also thrown out by a similar error in the time of transit, so that Lalande, 5,520, requires a correction of 5m. in R.A. With regard to No. 45,400, the suspicion of variability is probably occasioned by a misprint in the "Histoire Céleste," since Piazzi, Bessel, and others estimate the magnitude the same as at present. THE ANNULAR ECLIPSE OF JANUARY 22, 1879.-The first of the annular eclipses of the ensuing year, a return of that of January 10, 1861, which was central in Australia, commences in Uruguay, whence the belt of annular phase traverses the South Atlantic, passing over Tristan d'Acunha, the few inhabitants of which islands may probably be startled by seeing the sun transformed into a narrow luminous ring while he is high in their heavens. The central line crosses the African continent in the direction of Pemba Island, north of Zanzibar, where the annularity will continue nearly three minutes: the middle of the eclipse at 4h. 6m. P.M., local mean time. GEOGRAPHICAL NOTES THE Council of the Royal Geographical Society have determined to commence, on January 1, 1879, the monthly issue of a new series of their Proceedings, under the title of The Proceedings of the Royal Geographical Society and Monthly Record of Geography. The latter part of this title will, we believe, fairly indicate the nature of the contents, which will include the papers read at the evening meetings, original articles, geographical notes, obituary notices, proceedings of geographical societies, and brief analytical notes on new books and maps. Each monthly number will be illustrated with one or more maps, and no doubt in this respect endeavours will be made to meet the wants of a public larger than that contained within the ranks of this popular society, which now numbers some 3,400 members. SO IN connection with this we regret to announce that this month's number of the Geographical Magazine brings the career of that journal to a close. This regret, however, is considerably mitigated by the fact that the new form of the Geographical Society's organ is intended to take the place of the journal which for so many years has been so ably conducted by Mr. C. R. Markham. Mr. Markham deserves great credit for his disinterestedness in continuing to carry on a journal which aimed successfully to be the organ of scientific geography in this country. The volumes will form a valuable record of the progress of geography for the period over which they extend. In the December number Mr. Markham gives an account of the career of the journal since its first start as Ocean Highways in 1870. We trust that the new organ will prove a worthy successor of its predecessor, and that while giving due prominence geographical news, the conductors will aim at bringing geography under the guidance of sound scientific principles. to THE Church Missionary Society have recently received from Mr. A. M. Mackay, of their Nyanza Expedition, the journal of his experiences, extending from December 31, 1877, to May 16, 1878, in which occur some useful suggestions to African travellers, as well as information of considerable interest to geographers. On April 30 Mr. of 350 miles, undertaken with the view of aiding the Rev. C. T. Wilson, and he promises a detailed account of his troubles then on another occasion. In the course of this march he had to cross the extensive wilderness of Mgunda Mkali, which he describes as being for the most part not merely a swamp, but this year more under water than above it. Day after day the party waded and splashed through mud and water, now over the ankles, sometimes up to the knee, and here and there up to the waist or higher. Hopeless and still more hopeless, Mr. Mackay remarks, the wading seemed to become, and he found that they were crossing what was neither more nor less than the source at once of the Nile, the Congo, and the Rufiji. This gigantic boggy plain or moss Cameron calls the Nya Kun Swamp, and, where Mr. Mackay crossed it, in S. lat. 5° 20′, his aneroids recorded an average elevation of 4,000 feet exactly. To the north, in Usukuma, the swamp narrows itself into the sluggish Lewumberi River, the most southerly of the sources of the Nile. From this swamp, too, the rapid Mdaburu River takes its rise, and flows southward into the Ruaha, in Unyoro, and Uhehe, and thence to the Indian Ocean, where it is known as the Rufiji. A day's march east of Tura Mr. Mackay found the swamp contract to a breadth of 300 yards, with increased depth, and slight indications of flow to the southward; it then rounds to the west, steering clear of Iiwe-la-Singa, and, after two more days, it was crossed-a flooded, five-armed river, flowing rapidly north at an altitude of 3,700 feet. Here it is called the Nghwala River by the Wanyamwezi, from the number of partridges on its banks. In Speke's map alone it would seem that the true course of the river is indicated; it flows north-east to Mirambo's country, where it is known as the Ngombe (i.e., ox) River, and finds its way into the Malagarasi, thus aiding that river in bringing Lake Tanganyika nearer to permanent overflowing, when the Lukuga-which has been such a bone of contention to two great travellers-will no longer be a swamp but a decided stream, and the waterline of the Congo will run from Loango on the West Coast to the confines of Ugogo. LALANDE'S STARS, NOS. 5,499 AND 45,400.- Mr. J. E. Gore writes suggesting variation in both these objects. | Mackay reached Uyui, after a hurried and tedious tramp THE London Missionary Society have received a letter from the Rev. J. B. Thomson, dated from Ujiji, announcing the safe arrival on August 23 of the main body of the Society's expedition at its destination on Lake Tanganyika. Though, as will be remembered, this expedition met with a long series of disasters and delays in the coast region, they have now been successful in performing one of the quickest and most prosperous journeys from Mpwapwa to Ujiji, having been but seventy-three days on the road. Messrs. Thomson and Hore have already found an apparently healthy site for their station close to Kinegoma Bay, and about three miles from Ujiji. WE learn from a Japan paper that an American gentleman has been engaged for some time past in surveying the Island of Yezo, as well as in making geological investigations. The result is said to be that there are 7,000 square miles of land fit for agricultural purposes, and 6,000 suitable for pasture, while there are 5,000 square miles of forests and 9,000 of volcanic mountains and mineral country. An impression appears to prevail that the Government wish to encourage emigration to this thinly-populated part of the Japanese empire. As an erroneous impression prevails that nothing is known of the scientific work done by the Portuguese African expedition previous to the date mentioned in last week's NATURE, it may be interesting to give, as instances of the service which they are rendering to geography, the positions of some of the places determined by Senhor Serpa Pinto and his colleagues:-Benguela, long. 13° 25′ 20′′ 45", lat. 12° 34′ 17", alt. 7 metres ; Dombe Grande, long. 13° 7' 45", lat. 12o 55" 12', alt. 98 metres; Quillenques, long. 14° 5' 3", lat. 14° 3' 10", alt. 900 metres; Caconda, long. 15° 1' 51", lat. 13° 0' 44", alt. 1,678 metres; Bihé, long. 16° 49′ 24′′, lat. 12° 22′ 40", alt. 1,670 metres. The longitudes are stated to be chronometrical. Dr. EDWIN R. HEATH, of Wisconsin, is about undertaking the exploration of the Beni and Madre di Dios Rivers of Brazil, his sojourn in South America some years as secretary of legation in Chili giving him excellent advantages for this purpose. Dr. Heath had arranged to visit South America with Prof. Orton, but was detained, and he now desires to carry out some of the work that the untimely death of that well-known explorer has left uncompleted. THE latest advices from Mr. Frederick A. Ober, of whose explorations in the West Indies on account of the Smithsonian Institution we have given notice from time to time, were from Point à Pitre, Guadeloupe, on September 23. He was about to leave for the United States, expecting to arrive some time between the middle and end of October. Since his last report he has obtained quite a number of additional collections, and hoped to complete the material for the proposed catalogue of the birds of the West Indies. So far the collections sent forward by him to the Smithsonian Institution have been found to contain some seventeen undescribed species of birds, as determined by Mr. George N. Lawrence, of New York. AN interesting account of a recent visit to Pitcairn Island by Admiral De Horsey in the Shah, forwarded to the Admiralty, will be found in yesterday's Daily News. The people are evidently as primitive and well-conducted, and on the whole as comfortable as ever. IN a previous number we referred to a work of The great geographical interest-"Die Sahara, von Oase zu Oase," by Dr. Joseph Chavanne, published by Hartleben, of Vienna. At that time the work was in course of publication, and we refer to it now to announce its completion in twenty parts. The last parts are in every way equal to the earlier ones, and if anything the interest is rather increased than otherwise. work contains numerous woodcuts, besides seven coloured plates and a map of the great desert; its perusal will be found extremely attractive by any one taking interest in geographical science. The exact route which Dr. Chavanne describes is the following: -The travellers start from Tripolis through the Fezzan to Mursuk, then westward to Rhat, the land of the Tuareg or Imoshag. From Rhat they turn northward to Rhadames, thence to Biskra in Algeria. Here the travellers again turn their backs to the Mediterranean and proceed in a south-westerly direction by way of El Aruat and El Golea to Insalah. From Insalah they go to Tafilet, in the extreme north-west of the desert, and thence many thousand miles to the south to Timbuctoo. The Oasis of Air or Asben is the next station, situated due east from Timbuctoo, then Tibesti, the land of the Tebbu. Thence they turn to the northeast to the Jupiter Ammon Oasis, which is the furthest point to the east reached. The travellers then turn westward again and return to Tripolis by way of Audschila. ON THE DEVELOPMENT OF THE GARPIKE THE gar or bony pike of North America is one of the most interesting of living fishes. The best known species of the genus to which it belongs is the Lepidosteus osseus. This species owes the grammatical form of its scientific name, and, indeed, its first scientific description to the elder Agassiz, and we have now to record the filling up of the last details of its life-history to the younger Agassiz. Known for over three-quarters of a century, it has been only within the last few months that the young fish as they escape from the egg have been seen, and it has been the good fortune of Alexander Agassiz to succeed in hatching the eggs and raising the young until they showed at least the principal structural peculiarities of the adult. A short account of the chief facts in connection with this stage of the bony pike's history will appear in the forthcoming number of the Proceedings of the American Academy of Arts and Sciences; from an advance copy we cull the following details :The spawning-ground selected for observation was the Black Lake, at Ogdensburgh, N.Y. Mr. Garman, who describes the scene, and Mr. Blodgett, who rendered most essential assistance, deserve the thanks of every naturalist. The eggs collected were carried by the hand in pails from Ogdensburgh to Cambridge, where their progress was watched by Prof. A. Agassiz. The fish began to spawn about May 18. Little projections of granite stand out here and there into the lake. The frosts from time to time have broken off from these, small angular blocks, which lie piled together under the water at depths varying from two to fourteen inches. Into these shallows the female fish would come, each of them attended by two males. While very timid when in deep water, they seemed to be courageous to recklessness when they approached the shallows. On they would come in threes, when rising to the surface of the water, and thrusting their bill out of it they would open this widely, then take in air, and close it with a snap. In some few cases three or four males would be in attendance on one female, but much more often there would be but two, and these would swim resting on either side of the female fish, their bills reaching up toward the back of her head. At times the water would be lashed into all directions with their conjoined convulsive movements. The eggs when laid were excessively sticky; to whatever they happened to touch they stuck, and so tenaciously, that it was next to impossible to release them without tearing away a portion of their envelopes. It is remarkable that, as far as could be seen, there was, on and about the spawning ground, a complete absence of anything that might serve as food for the young fish. Of the quantity of eggs brought to Cambridge, only thirty hatched, and not one of those artificially fecundated was hatched. In Prof. A. Agassiz' anxiety not to spoil this interesting experiment he did not venture to exa-mine any of the fresh eggs; so that the history of their segmentation and very early development remains to be worked out. The envelope of the eggs is very opaque and of a yeilowish green, like that of toads. Of the thirty hatched out by the end of May, twenty-eight were alive in the middle of July last. When first hatched the young fish possesses a gigantic yolk-bag, and the posterior part of the body presented nothing specially different from the general appearance of any ordinary bony (teleostean) fish of the same age; but the anterior part was most extraordinary: it looked like a huge mouth cavity, extending nearly to the gill opening, and crowned by a depression like a horse's hoof in outline, along the margin of which were a row of protuberances acting as suckers. The moment the young fish was hatched it attached itself to the sides of the vessel by means of these, and would hangimmovable. The eye was not veryadvanced, the body was transparent, the gill covers were pressed against the sides of the body; the tail was slightly rounded, the embryonic fin is narrow, and there were no traces of embryonic fin rays; the olfactory lobes were greatly developed and elongated as in sharks and skates; the chorda was straight. On the third day the body became covered with minute black pigment cells, and then was noted the first traces of the pectoral fins, and the snout became more elongated; the great yolk-bag was greatly reduced in size. About the fifth day were seen traces of the caudal, dorsal, and anal fins. Gradually the snout became elongated, the suckers concentrated, and the disproportionate size of the sucking disc became reduced, so that when about three weeks old it became altogether more fish-like. The sucking disc was now reduced to a swelling at the top of the upper jaw, the yolk-bag had disappeared, the gill covers extended well upto the base of the pectorals-these latter were in constant motion, and thetail exhibited the same rapid vibratile movements. Theyoung fish now begins to swim about, and is not so dependent upon its sucking disc, and at last this only remains as a fleshy globular termination on the snout. At this stage, too, the young have the peculiar habit of the adult fish of coming to the surface to swallow air. When they go through the process under water of expiring this air they open their jaws wide and spread their gill-cover, and swallow as if they were choking, making violent efforts, until a minute bubble of air has become liberated, when they become quiet again. Their growth is rapid. Within a month the teeth made their appearance, and some of the fin-rays on the fringe of the pectorals were to be seen. Prof. A. Agassiz draws the following conclusions from these observations:- "That notwithstanding its similarity in certain stages of its growth to the sturgeon, notwithstanding its affinity with sharks by the formation of its pectorals from a lateral fold, as well as by the mode of growth of the gill openings and gill arches, the Lepidosteus is not at all so far removed as is generally supposed from the bony fishes." The memoir is illustrated by five plates containing some forty-five figures, and is only to be regarded as a preliminary account, but it is a preliminary account of such exactness, importance, and interest, that no apology is necessary for bringing it at once under the notice of our readers. This memoir was presented to the American Academy as recently as October 8 last. E. PERCEVAL WRIGHT THE MUSIC OF COLOUR AND MOTION AT the Physical Society, on November 23, 1878, Prof. W. E. Ayrton, late of the Imperial Engineering College, Tokio, Japan, read a paper, written by himself and Prof. J. Perry, of the same college, on "The Music of Colour and of Visible Motion." The authors began by pointing out the well-known fact that emotion is excited by moving bodies, and they believed that, upon this basis, a new emotional art would be created which would receive a high development in the far distant future. All methods of exciting emotion could be cultivated; but of these, music, by reason of the facility with which its effects could be produced, had alone been highly perfected by the bulk of mankind. Sculpture and painting are not purely emotional arts, like music, inasmuch as they involve thought. It would take a long time and much culture for the eye to behold moving figures with similar emotional results to those of the ear on hearing sweet sounds; but time and culture only might be necessary. It might be due to their neglect of this emotional tendency that the Western nations felt little emotion at moving visual displays. For among the Eastern nations they had entertainments consisting of motions and dumb show, which, although incomprehensible and even ludicrous to the European, powerfully affected the feelings of a native audience. In Japan the authors had seen whole operas of "melodious motion" performed in the theatres, the emotions being expressed by movements of the body, affecting to the audience, which were quite strange to them. The accompanying orchestral music was, withal, displeasing to the authors, while, on the other hand, Western music is mostly displeasing to the Japanese. The emotions produced by rapidly-moving masses, such as a train bowling up to a bridge, or by changing colours, as in sunsets, have been felt by all, and those excited when the moving bodies are very large do not seem to be producible by anything else in nature. Harmonic instruments have been constructed to exhibit the combination of two or more pairs of harmonic motions to the eye; for example, Blackburn's pendulum, Lissajous' forks, Wheatstone's kaleidophone, Yeates' vibrating prisms, Donkin's and Tisley's harmonographs, and Hopkins' electric diapason. Prof. Ayrton illustrated his remarks by exhibiting these instruments in action. The pendulum traced out the complex path of the combined otions by a jet of falling sand, the forks or prisms by a moving beam of light thrown on a screen, the kaleidophone by a bright bead, and the harmonograph by the involutions of an aniline pen. With none of these and such like instruments, however, is the production of mere emotion the end in view; and in some of them no change can be made in the periods of the pairs of harmonic or periodic motions combined without arresting the instrument, a proceeding which in music would be analogous to stopping the tune at the end of every chord. There is no provision either for changing the amplitude or phase, equivalent in music to an inability to render, at will, a note forte or piano, or rather as it is not only the strength of the entire note, but even the amplitude of the various component harmonics that these instruments cannot regulate, it would be as if in music there was the probability of a note marked in the score as piano for the flute being rendered by a loud blast from a trumpet. A successful instrument in the new kinematical art must at least visibly render changes in period, amplitude, and phase of the harmonic motions represented. Profs. Perry and Ayrton had designed an instrument, which is now in Japan, for effecting these required changes in a combination of harmonic motions given to a moving body, and which they claimed to be the first musical instrument of the visual art in question. They had not given it a name yet, because the nomenclature of the subject was uninvented. Photographs and diagrams of this instrument were exhibited to the meeting. It consists of a mechanical arrangement of sliders, pulleys, and cords, whereby two motions, one along a vertical, and the other along a horizontal line, and each consisting of the sum of a number of harmonic motions the period, amplitude, or phase of any one of which can be varied at will, are compounded in the resultant motion of a suspended pane of glass. A black circle painted on the pane is intended to represent the moving body as projected against a wall or screen behind. The sliders controlling the motion of the pane are actuated by a revolving barrel, the periphery of which is carved according to mathematical principles, so as to give the different harmonic motions to the sliders in one revolution. The motion is further regulated by shifting the sliders either parallel to the axis or at right angles to the radius of the revolving barrel; and by the angular velocity of the barrel. In this way the period, amplitude, and phase of the component motions of the glass either in a vertical or horizontal direction, may be changed at will, and almost immediately. Other kinds of periodic motions may be compounded in a similar way. Prof. Ayrton also suggested other forms of apparatus for this purpose. Numberless combinations of graceful motions producing emotional effects on the beholder can by its means be given to a visible body. It is the intention of the authors to construct an improved form of the apparatus, and to arrange for the blending of colour with the moving body to heighten the emotional influence; for example, they purpose having changing mosaics of different hues, thrown upon the screen for a background to the black spot. This can be done by means of an instrument similar to the chromotrope with its revolving sheets of parti-coloured glass. In conclusion Prof. Ayrton said that there might yet be invented many different ways of producing these spectacles, and there was no reason why a whole city full of people should not enjoy these displays projected upon the clouds overhead. THE SWEDISH NORTH-EAST PASSAGE EXPEDITION FROM letters despatched from the mouth of the Lena by Prof. Nordenskjöld on August 27, which have just been published in the Gothenburg Handels Tidning, we learn that the Vega accompanied by the Lena left Dickson Harbour, at the mouth of the Yenissej, on August 10, the weather being fine. On the 11th ice was seen, but it consisted almost exclusively of bay ice which did not obstruct navigation, which, however, was rendered difficult by a thick fog. The salinity of the water began gradually to increase and its temperature to fall. Organic life at the bottom grew richer at the same time, so that Dr. Stuxberg on the night between August 13 and 14, while the vessel lay anchored to a drift-ice floe, collected with the swab a large number of beautiful pure marine types; for example, large specimens of the remarkable crinoid, Alecto eschrichtii, numerous asterids (Asterias linckii and panopla), pycnogonids, &c. The dredgings near the land now too began to yield to Dr. Kjellman several large marine algæ. On the other hand the higher plant and animal life on land was still so poor that the coast here forms a complete desert in comparison with the rocky shores of Spitzbergen or West Novaya Zemlya. Auks, rotges, loons, and terns, which are met with on Spitzbergen in thousands upon thousands, are here almost completely absent. Gulls and Lestris which there fill the air with continual sound occur here only sparingly, each with two species, and it appears as if they quarrelled less with one another. Only the snow-bunting, six or seven species of waders, and a few varieties of geese are found on land in any great numbers. If we add a ptarmigan or two, a snowy owl, and a species of falcon, we have enumerated the whole bird fauna of the region, at least so far as the Swedish expedition have been able to ascertain it. Of warm-blooded animals in the neighbouring sea, only two walruses and some seals, Phoca barbata and hispida, were met with. There is probably great abundance of fish. Cosmic dust was sought for on the ice without success, but there was found upon it some yellow specks which, on examination, were found to be a coarsegrained sand, consisting exclusively of very beautifullyformed crystals up to two millimetres in diameter. The nature of these crystals was not ascertained, but it was evident that they are not formed of any ordinary terrestrial mineral, but possibly of some substance crystallised out of the sea-water during the severe cold of winter. The Vega lay at anchor from August 14 to 18 in a harbour named Actinia Harbour, from the number of these animals brought up by the dredge from the seabottom. This harbour is situated in a sound between Taimyr Island and the mainland. The land was free of snow, and covered with a greyish-green turf formed of a close mixture of grasses, mosses, and lichens, forming a reindeer pasture much superior to that of the valleys in Spitzbergen which abound in reindeer. Only a few reindeer, however, were seen here, probably owing to the presence of wolves. The number of phanerogamous plants is exceedingly small; the moss and especially the lichen vegetation, on the other hand, abundant enough. Actinia Harbour is an excellent position for a meteorological station. The fog still continuing, the Vega and the Lena sailed again on the 18th, and reached Cape Chelyuskin on the 19th, anchoring in a little bay which indents the low promontory, dividing it into two parts. The western point was found to be situated in 77° 36′ 37" N. L., and 103° 25' E. from Greenwich, and the eastern in 77° 41′ N. L., and 104° 1' E. L. Inland the mountains appeared to rise by degrees to a height of 1,000 feet. These mountains, as well as the plains, were free of snow. Only here and there were to be seen large white patches of snow in hollows on the mountain sides or in some small depression on the plains. At the beach, however, the ice-foot still remained at most places. |