which is also thin and wavy-margined. Placed upon a mass of Sargassum in an aquarium, the Scyllaea was hard to find, so closely did it imitate the appearance of the leaves. To make this an undoubted case, the Scyllaea should have been found upon the gulf-weed, and should never occur anywhere else.1 This was found on the sand; and it is the only specimen that has ever been found by our party, so that we may consider it a rarity. As it can swim very readily, almost like a heteropod in this respect, and is naturally found only in the outside waters, the chances were against their being found in any numbers. It seems to me that there can be but little doubt that this creature presents another interesting case of mimicry, and deserves mention, and additional observation if any one is so situated as to be able to make it. HENRY LESLIE OSBORN. PROFESSOR HUXLEY ON DARWIN. OUR readers have been informed, that, through popular international subscription, a fund had been raised to erect a statue to Charles Darwin, and that this was recently unveiled with appropriate ceremonies at the new museum of natural history in South Kensington. We copy from Nature the address upon that occasion, made by Professor Huxley in the name of the committee, to the Prince of Wales as representative of the trustees of the British museum. We accompany it by a portrait and signature of Darwin, taken from a photograph obtained in London in 1872, and inscribed, "I like this photograph better than any other which has ever been taken of me. CH. DARWIN." "YOUR ROYAL HIGHNESS, - It is now three years since the announcement of the death of our famous countryman, Charles Darwin, gave rise to a manifestation of public feeling, not only in these realms, but throughout the civilized world, which, if I mistake not, is without precedent in the modest annals of scientific biography. "The causes of this deep and wide outburst of emotion are not far to seek. We had lost one of those rare ministers and interpreters of nature whose names mark epochs in the advance of natural knowledge; for, whatever be the ultimate verdict of posterity upon this or that opinion which Mr. Darwin has propounded, whatever adumbrations or anticipations of his doctrines may be found in the writings of his predecessors, the broad fact remains, that since the publication, and by reason of the publication, of the 'Origin of species,' the fundamental conceptions and the aims of the students of living nature have been completely changed. From that work has sprung a great renewal, a true instauratio magna of the zoological and botanical sciences. 1 Dr. Breitenbach, in the article above referred to, mentions without any names, and with too vague description for indentification, a creature on the Sargassum that would seem to be Scyl laca. "But the impulse thus given to scientific thought rapidly spread beyond the ordinarily recognized limits of biology. Psychology, ethics, cosmology, were stirred to their foundations; and the Origin of species' proved itself to be the fixed point which the general doctrine of evolution needed in order to move the world. 'Darwinism,' in one form or another, sometimes strangely distorted and mutilated, became an every-day topic of men's speech, the object of an abundance both of vituperation and of praise more often than of serious study. "It is curious, now, to remember how largely, at first, the objectors predominated; but, considering the usual fate of new views, it is still more curious to consider for how short a time the phase of vehement opposition lasted. Before twenty years had passed, not only had the importance of Mr. Darwin's work been fully recognized, but the world had discerned the simple, earnest, generous character of the man, that shone through every page of his writings. "I imagine that reflections such as these swept through the minds alike of loving friends and of honorable antagonists when Mr. Darwin died, and that they were at one in the desire to honor the memory of the man, who, without fear and without reproach, had successfully fought the hardest intellectual battle of these days. "It was in satisfaction of these just and generous impulses that our great naturalist's remains were deposited in Westminster Abbey; and that immediately afterwards, a public meeting, presided over by my lamented predecessor, Mr. Spottiswoode, was held in the rooms of the Royal society for the purpose of considering what further steps should be taken towards the same end. "It was resolved to invite subscriptions, with the view of erecting a statue of Mr. Darwin in some suitable locality, and to devote any surplus to the advancement of the biological sciences. Contributions at once flowed in from Austria, Belgium, Brazil, Denmark, France, Germany, Holland, Italy, Norway, Portugal, Russia, Spain, Sweden, Switzerland, the United States, and the British Colonies, no less than from all parts of the three kingdoms; and they came from all classes of the community. To mention one interesting case, Sweden sent in 2,296 subscriptions from all sorts of people;' as the distinguished man of science who transmitted them wrote, from the bishop to the seamstress, and in sums from five pounds to twopence.' "The executive committee has thus been enabled to carry out the objects proposed. A 'Darwin fund' has been created, which is to be held in trust by the Royal society, and is to be employed in the promotion of biological research. The execution of the statue was intrusted to Mr. Boehm; and I think that those who had the good fortune to know Mr. Darwin personally will admire the power of artistic divination which has enabled the sculptor to place before us so very characteristic a likeness of one whom he had not seen. "It appeared to the committee, that, whether they regarded Mr. Darwin's career or the requirements of a work of art, no site could be so appropriate as this great hall; and they applied to the trustees of the British museum for permission to erect it in its present position. That permission was most cordially granted, and I am desired to tender the best thanks of the committee to the trustees for their willingness to accede to our wishes. I also beg leave to offer the expression of our gratitude to your royal highness for kindly consenting to represent the trustees to-day. along the coast between the Yellow Sea and the Bay of Bengal. Evidently the solution of the problem of reaching western China is to be sought in the course of these rivers or on their banks. The first of these rivers to the east is the Yang-Tze-Kiang, which may be easily ascended for seven hundred kilometres. Junks can proceed above that as far as Sion-Choo, in Se-Chuen; but it is impossible to go higher, and consequently impossible to reach Yun-Nan. South of the Yang-Tze-Kiang is the Si-Kiang, or Canton River, navigable to the city Pe-se, nine hundred kilometres. Regular caravans then proceed by land to Yun-Nan, a route which is shorter than by the Yang-Tze-Kiang. But Song-Ka, the "It only remains for me, your royal highness, my lords and gentlemen, trustees of the British museum, in the name of the Darwin memorial committee, to request you to accept this statue of Charles Darwin. We do not make this request for the mere sake of perpetuating a memory; for, so long as men occupy themselves with the pursuit of truth, the name of Dar win runs no more river of Tonquin, offers a shorter route than this; and Lieut. Kergaradec says that steamers of light draught can reach Laos-Kai, on the Chinese frontier, while junks ascend to MangHao, in the centre of the YunNan territory. We have nothing to hope from the Me-Kong. Its outlet is much farther away, and rapids are numerous. It is impossible at present to seriously think of building a railway on its banks a thousand kilometres in length, and, what is more, in an unknown, savage, and hostile country, and one of the most moun tainous regions of the world. The Saluen empties into the Indian Ocean; but in most of its course it flows near the Me-Kong and Yang-Tze-Kiang, and traverses with them the province of Yun-Nan. Starting from Martaban, a stone road could proceed to the junction of the Main-Long-Gye, follow this river, traverse the mountain range which separates the basins of the Saluen and the Me-Nam, proceed to Zimme, then to Kiang-Hai, descend the He-Kok to the Me-Kong, and ascend this river to the frontier of China, and even as far as Talifu. This is a long and very hilly course; for it is necessary to pass from one basin into a second, then into a third, and, further, to build the route into the valley of the Me-Kong, - a plan any thing but practicable. It means gigantic labor and incalculable expense, without considering the probable hostility of the population. A railway already follows the lower course of the Irrawadi, between Rangoon and Prome. This route has just been extended to Tungu on the Sitang, and ultimately will proceed to Mandelay, and even to Bhamo. A branch could be made at Mandelay, and touch the Me-Kong at Kiang-Tung, though in this comparatively short space it must cross at least eight mountain chains having a height of two thousand metres. One can imagine the inclination of the sides and the depth of the valleys among mountains so near each other. The Saluen flows seven hundred metres below the hills which border it: it is therefore out of the question to consider this. Another project is to start from Bhamo, and to reach Talifu by Man-Wyne or Momein. In this territory the hills are even more marked, more abrupt, and steeper, than in the preceding, and the population is much to be feared. Even the Brahmapootra has been suggested: it is easily ascended to Sooja, partly by rail, partly by steam; but above this the route is impracticable, there being a rapid and uninterrupted succession of high mountains and highbanked rivers. To summarize these data, the two Chinese rivers must be abandoned, not precisely on account of the difficulties of the territory, but because for a long time the celestial empire will be more or less impenetrable and dangerous for Europeans, and the course of the Me-Kong is too long and too hilly. The routes which traverse the bed of the Brahmapootra and the valley of the Irrawadi present such obstacles that they are impracticable. The route of the Saluen is more attractive; but it must not be forgotten, that, besides its length, it must cross two watersheds, one of which at least is very difficult, and must ascend the Me-Kong for a very long distance. The route by the Red River remains, which is not at all wonderfully accessible; but, to establish communications with Yun-Nan and with Se-Chuen, some obstacles must be surmounted; and this is the course which offers fewest of them. Beside the fact that it is shortest, it will not be necessary to cross mountains or to traverse valleys. The French recently sent a commission of engineers to survey for a railway between Tonquin and Burmah. We doubt whether this project can be realized; but these investigations will necessarily bring forth important data in regard to the penetration of western China. THE GEOLOGY OF JAPAN. THE Japanese geological bureau has prepared a series of maps illustrative of the geology of the Japanese archipelago, to be presented at the Geological congress at Berlin this year. The bureau was established in 1879, and includes topographical, geological, and agronomical departments, and a chemical and technical laboratory officered by Germans. The area already surveyed by the topographers is about eighty geographical miles square; and the whole country is expected to be surveyed and mapped in about eight years more. The geological survey has reached about the same extent as the topographical. The maps and accompanying text are being published in both Japanese and English. The agronomical survey was begun in 1882. A map showing the knowledge at present attained, of the geological structure of Japan, is amongst the series. The observations made are summarized as follows: All the geological formations are met with in Japan. Gneiss occurs in small quantities in the neighborhood of Nagasaki and in the centre of the main island. Crystalline schists, consisting of mica, talc, marble, serpentine, etc., are found in Shikoku and the south-west of the main island. The paleozoic formations embrace the largest portion of the country, and are found everywhere. The mesozoic formation, including trias, jura, and chalk, is also known in Japan, but is not so prevalent as the previous one. Trias occurs in the north and south-west of the main island and in Shikoku. Chalk is found widely distributed in Yezo, the main island, and Shikoku. The cenozonic formation, including the tertiary and quaternary, is found everywhere on the edges of the older mountain ranges. In these formations numerous remains of mammals are found, especially of prehistoric elephants. Of the Plutonic rocks, granite is found widely distributed, and covers, next to the paleozoic formations, the widest area. The volcanic rocks consist mostly of trachyte and andesite: basalt is rare. Among the soils in Japan is the so-called tuff, i.e., volcanic tuff, which, for the most part, consists of decomposed silicates, and which is of great importance to agriculture. It is almost wholly unknown in Europe, while in Japan it forms the greater part of the so-called hara, which are the uncultivated plains at the foot of mountains, but which will bear cultivation. Accurate knowledge of this kind of soil will be of the utmost moment to Japanese agriculture. It is also noticeable that Japanese soils in general are very poor in chalk, and would therefore be improved by the addition of marl and chalk. AMERICAN ENGINEERS AT DEER THE annual convention of the American society of civil engineers, just held at Deer Park, Md., June 24-26, will be remembered as one at which more business was transacted, and more discussion elicited, than at any previous convention of the society. In fact, the limit in this direction may fairly be said to have been reached; and the thin attendance at the meetings of the last day was followed early in the afternoon by a motion, which was unanimously carried, that the reading of the remaining papers be dispensed with, as the members were too tired to listen to them. The experience at the conventions of the past few years had indicated the advisability of devoting less time than formerly to excursions and sight-seeing; and the meeting this year was therefore purposely held in a place offering little of local engineering interest, and where almost the whole time could be devoted to the business of the occasion. The convention was attended by over one hundred members; and the proceedings were opened on Tuesday, June 23, by the reading of a very interesting paper by Mr. E. B. Dorsey, entitled 'English and American railroads compared.' It appears that the average cost of the English railroads has been $202,227 per mile, as against $62,176 for the American roads. At six per cent, to justify this increased expenditure, that part of the operating expenses which is affected by good or bad construction should involve a saving of about $8,000 per mile per year in the case of the English roads. The comparisons of the writer showed that this was by no means the case, the saving being rarely over $1,000. Comparisons of this kind, however, cannot pretend to be more than approximations, as the items of expense cannot always be accurately separated; and, moreover, the figured cost of English roads probably includes the cost of parliamentary proceedings in obtaining the charter. Regarding the physical characteristics of the English roads, few of them attain elevations of nine hundred feet above the sea; and their construction, therefore, offered few engineering difficulties, their greater first cost having been due to the almost entire absence of temporary structures. Recently several miles had been laid with steel sleepers, weighing a hundred and twenty-four pounds, on the London and north-western railway, following the example of the German roads, where they are quite common. Of freight-cars, only about twenty per cent have brakes in England; and these are so placed that they cannot be operated when the train is in motion: so the only effective ones are those on the engine and caboose. And in passenger-trains, where the air-brakes are used, but where only one car in three or four has a hand-brake, platform-cars heavily loaded with cast-iron, and provided with powerful hand-brakes, are attached on steep grades, to hold the train in case of accident to the air-brakes. Prof. T. Egleston of New York presented an interesting paper on the cause and prevention of the decay of building-stones. In the speaker's investigation of the decomposition of calcareous materials due to the action of city gases and rain-water, he had found that the action was a maximum at a height of ten feet above the ground, above which point it decreased, and was null above a height of a hundred feet. To prevent decay, the only remedy was to make the stone water-proof. The speaker believed that a wash of sulphur was the only thing of value, where the stone was a dolomite, according to some experience in England. In the case of all porous stones, he considered that an effectual remedy would be to immerse the stone in boiled linseed-oil, renewing the application until the stone was saturated. Some discussion on this paper took place, many members believing that the use of oil would prevent the formation of a good bond between the stones and the mortar. It was stated, however, that the method had been tried with success in England. A valuable and extensive report was presented by the committee on the preservation of timber, whose work has covered five years. It appears from the experience in this country that Kyannizing, or treat ment with corrosive sublimate, though of value when the wood is only exposed to occasional moisture, is not efficacious when the wood is permanently wet. Although the testimony obtained was somewhat conflicting, the committee recommended the process of Burnettizing (chloride of zinc) as the best process for preserving railroad ties, principally on account of the low cost, which was only from twenty to twentyfive cents a tie. Creosoting was found too expensive; although it is the only effectual method for wood exposed to the attacks of the teredo and limnoria, and is, without doubt, the most generally successful process. In connection with this report, a report was presented by Mr. F. Collingwood, on the preservation of forests. A paper followed by Mr. Jos. M. Wilson of Philadelphia, on specifications for iron and steel railroadbridges, which was succeeded by a long discussion regarding the cantilever bridge at Niagara Falls, on which a paper had previously been presented to the society. The specifications for this bridge, in which steel was used for all the principal compression members, provided for the use of open-hearth steel alone. In this discussion the opinion was very generally expressed that Bessemer steel should not have been barred out, and that in drawing up specifications the engineer should insist simply on a certain quality as determined by physical tests, leaving the manufacturer free in the method of manufacture. It is probable in this case, however, that Bessemer steel was excluded to prevent delays in getting steel from works that had not had experience in making steel for structural purposes, as most of the Bessemer works had been making rail steel, and not structural steel. The fact that in making the steel for this bridge a hundred and thirty-six beats out of two hundred and forty-five were rejected, showed, in the opinion of many members, that engineers were requiring too much of steel, that the specifications were too rigid, and that a softer steel should have been used. Among the remaining papers presented, brief mention may be made of a few. Mr. J. A. Ockerson described a new apparatus for printing conventional topographical signs upon maps by means of a roller. Mr. Clemens Herschel gave a new method of determining the discharge over a submerged weir. Capt. Michaelis read a paper entitled 'Can we make heavy guns?' Professor Egleston added his testimony that there would be no difficulty in making caststeel guns of a hundred or even a hundred and fifty tons. Mr. C. B. Brush explained the method of aerating the water supplied to Hoboken. The bad taste and disagreeable odor previously existing had been entirely remedied. In addition to the reading of papers, some important business was transacted at the convention. There having been considerable discussion of late in regard to the proper relation to each other of the form of the head of a rail, and the flange, and tread of wheels, it was resolved that a committee of five be appointed to investigate this subject. It was also resolved to memorialize congress to appropriate the sum of ten thousand dollars to carry on tests of steel |