The equinox to which the elements are referred is given, since the vernal equinox is continually shifting on account of the slow motion of precession.

With what has gone before, I think that very little need be said in explanation of fig. 3, which is drawn from a model made as I have just described. The true form of a portion of the comet's orbit is given, and upon it is projected the earth's orbit, which, with such a small value of i, appears here again as a circle. The positions of the earth and comet are given for several dates.

Fig. 4 shows the entire orbit of Barnard's comet (as well as that of Wolf's comet, presently to be mentioned), the earth's orbit, that of Mars, and a small portion of the orbit of Jupiter. These orbits are all represented in one plane, and on so small a scale the inclinations are not great enough to cause any appreciable distortion. For the comets, the lines of nodes and the major axes are drawn in. Perihelion in all of the orbits is marked P; aphelion, A.

Fig. 5 is a map of a portion of the heavens showing the apparent path of the comet among the stars during the period of its visibility. It was in the constellation Lupus when first seen, and moved towards the north and east, through the constellations Scorpius, Sagittarius, Capricornus, and Aquarius. The place of the comet is given here, also, for July 16, the date of discovery; Aug. 16, perihelion passage; and Dec. 1, the limit of visibility.

COMET 1884 III (WOLF). — Wolf's comet, an insignificant object physically, is moving in an orbit of unusual interest. Its period is about six and three-fourths years. The entire orbit is shown in fig. 4, where two of the most interesting peculiarities are brought out, — a near approach to Jupiter in longitude 209°, May, 1875 (about eight million miles); and a near approach, at the descending node of the comet, to the orbit of Mars. From both of these planets the comet is evidently liable to considerable perturbation, and its past and future history become matters of some uncertainty.

Our chart shows a large part of the comet's apparent path in the heavens during its visibility. WILLIAM C. WINLOCK.

GEOGRAPHICAL NOTES.

THE roll of geographical journals is increased by one. The Florentine section of the Italian African society has been authorized by the central council and treasurer to issue a bulletin, the first two fasciculi of which appeared recently. It is intended to be partly eclectic, presenting geographical and especially African news to its readers, and partly the official record of the proceedings of the section. The present number contains an address by Professor Licata on the role of Italy in the Red Sea, an article by A. Mori on Massowah, and other matters of the same sort; bibliography, including a notice of a number of papers on the zoölogy of Africa, which have appeared from time to time in the annals of the civic museum of natural history in Genoa; African notes; the proceedings of the society; and the annual address of Vice-president Stefanelli on the operations of the section for 1884. The new journal is free to members, or may be subscribed for at the secretary's office, Via San Gallo No. 33, Florence, at the rate of five lire per annum.

Dr. Sériziat has been for two years engaged in collecting Lepidoptera at Collo, in the more wooded district of Algeria, reaching some thirty-five hundred feet above the sea. He has obtained about a hundred and eighty-four species in all, about as many as are ascribed to the whole of Algeria in the most recent catalogue. There are about fifty-two diurnal species, -just half as many as are found at Basle in Switzerland. The cause of this deficiency is stated to be the small number of succulent plants suitable for the food of larvae, and the incredible multitude of insectivorous birds. It would be a source of gratification if Collo would lend to America her surplus of the latter in place of our own inecffiient wild birds; and our climate would, perhaps, be quite well suited to the Algerian birds, at least in certain regions.

On the occasion of the presentation to the Russian representative, of the gold Vega medal recently awarded by the geographical society of Stockholm to Prjevalski, Mr. Elfwing, the American consul, made an address on behalf of the society, which was much appreciated, and which has been reproduced in the 'Revue géographique' of Renaud. Mr. de Berends made a suitable response on behalf of the absent explorer. This is the third award of the medal, the previous recipients being Baron Nordenskiöld and Capt. Palander.

The death of Madam Carlo-Serena, author of geographical articles on the Caucasus, is announced as having occurred in 1884 at an obscure villageOedips in Greece, on the borders of the Aegean. She was chiefly noted for her passion for mountain travel, and the courage and energy with which she

bore the concomitant privations and physical exertion it required.

The first general assembly for 1885, of the Geographical society of Paris, took place on the 24th of April. The president, Mr. de Lesseps, gave a brief address, in which he touched upon the much greater sensitiveness to occurrences in little-known lands, which the extension of telegraphs and means of transportation has brought about among the more civilized nations; and the growing importance, from all points of view, of geographical instruction in schools, universities, and even in the reading-matter furnished the general public by the daily and periodical

press.

Dr. Ballay, in an address on the new possessions of France in Africa, sums up by saying, that while the Ogowé can never be rendered navigable, it can at least be made useful for bateaux. Its basin is naturally fertile, and rich in resources. On the other hand, the country extending from this basin to the Kongo is generally sterile. Ivory is about the only product. There is little to hope for from this region; but it is the beginning of the practicable route for reaching the trade of the upper river, which has inhabitants of intelligence and thrift. The natural products of all this region, such as rubber, ivory, etc., may be expected to become rapidly exhausted. It should therefore be provided that artificial cultivation, new industries and crops, should be introduced and directed by the whites. In this way a permanent trade will arise, and commerce be permanently benefited.

From Iceland, under date of March 21, we learn that the shocks of earthquake which had devastated the vicinity of Husavik, North province, began Nov. 2, 1884, and continued at short intervals, but less energetically, until the 25th of last January. On this day stables were thrown down, springs burst from the ground in new places, and small elevations were visible in a formerly level sandy plain. It is singular that on every historical occasion when earthquakes have been felt in Spain, Iceland has simultaneously suffered: this may be due, however, to the prevalence of earthquakes in Iceland at all times.

The Corwin has returned from Bering Sea to San Francisco for some repairs. She reports the sea ice unusually far south in April and May in that No whales had yet been taken.

sea.

THE LIQUEFACTION OF OXYGEN.1 LIQUID ethylene, the use of which I have already explained to the Académie des sciences, furnishes, when boiled in the open air, a cold sufficient to cause oxygen, if compressed and reduced to this temperature, to present, when the pressure is diminished, a hard boiling appearance, which continues for an appreciable time. By evaporating the ethylene by the airpump, the temperature is sufficiently lowered to 1 Condensed from La Nature, May 16.

in reducing the temperature sufficiently to cause the complete liquefaction of oxygen. The process I use is very simple, and consists in evaporating the ethylene by forcing into it a current of air or of hydrogen at a very low temperature. In my apparatus, the steel receiver R, which contains the liquid ethylene, is attached to a copper worm three or four millimetres in diameter, closed by a screw-tap arranged in a glass jar, S. On turning into this jar some chloride of methyl, the temperature falls to - 25°; but if we blow into this air which we have dried by passing it through a flask, C, containing chloride of calcium, we soon have a cold of 70°. The ethylene thus cooled condenses, and fills the worm. When the tap is opened at the base of the jar S, the ethylene flows

under a slight pressure, and without apparent loss, into the glass gauge V, set, as shown in the figure, in a jar containing pumice-stone saturated with sulphurie acid, to absorb the water-vapor. It is indispensable to work in absolutely dry air; for otherwise the moisture of the air will condense in the form of an icy film on the walls of the gauge, which will become perfectly opaque.

It is then only necessary to evaporate the ethylene by means of a rapid current of air or of hydrogen cooled in a second worm, placed in the jar of chloride of methyl, S, to cause the oxygen compressed in the glass tube attached to the upper part of the reservoir O to be resolved into a colorless, transparent liquid separated from the gas above it by a perfectly clear meniscus. By working the pump P, the water acts on the mercury in the receiver O, and forces it into the gauge which contains the oxygen. The gas thus compressed liquefies in the branch of the tube in the gauge V. This tube dips into the ethylene at a temperature of - 125°. The mass of liquefied oxygen, which is as limpid as ether, is figured in black in the figure in order that it may be visible. By means of a hydrogen thermometer, I have measured the temperature of the ethylene, which in one of my experiments I found to be - 123°. I am in hope, that, by cooling the current of hydrogen more carefully, the temperature may be still further reduced. The copper worms in which the air and ethylene circulate are dipped into the chloride of methyl, which is rapidly evaporated by a current of air previously cooled. In conclusion, by evaporating liquid ethyl by a current of air or hydrogen much reduced in temperature, its temperature may be reduced below the critical point of oxygen, which in this way liquefies in the clearest form. This experiment is so simple and easy to perform, that it may enter into the regular course in a laboratory. L. CAILLETET.

THE FORM OF SHIPS.1

IN the course of his address, the lecturer briefly explained the great development which the science of fluid resistance had undergone of late years, largely owing to the labors of Stokes, Rankine, and others, but more largely still to those admirable investigations which had been carried out, under the patronage of the admiralty, by the late Dr. William Froude, and subsequently by his son, Mr. R. E. Froude. He likewise explained the very great effect which those investigations had produced in the royal navy, owing to the judicious and prompt adoption of Froude's results by the admiralty constructors. Stress was laid, throughout the lecture, upon the importance of adjusting the form and proportions of ships, not only to the loads which they have to carry, but likewise to the weight of the materials entering into their structure. It was a common error to judge of the merits of steamships by the relations which exist

1 From a lecture before the Institution of civil engineers by Sir EDWARd Reed.

between their displacement, steam-power, and speed, as expressed by formulae of various kinds. Approximations to the theoretical form of least resistance were sought by some naval designers, and all considerable departures from that form were regarded as objectionable. The lecturer, on the contrary, pointed out that no such theoretical form was any true or proper guide for a naval designer, since every change in the average weight of the hull necessitated a corresponding change in the form and proportions of the ship; and the great merit of a designer often was, that he adopted forms differing widely from the abstract forms of the schools, and presenting a very inferior appearance when put into what are known as 'constants of performance.' This was illustrated by examples derived partly from actual ships, and partly from calculations made for the purpose. Two actual war-ships were compared, one attaining the high figure of 213 marks when examined by the received formulae, and the other gaining but 172 marks; yet, in the lecturer's view, the latter was far the better ship, because she performed precisely the same service as the other, being inferior in no respect, and yet had cost less than the other by £114,000, and expended no more steam-power in attaining an equal speed. The lecturer remarked, that he should probably have regarded the abstract form of least resistance' with more respect but for the circumstance that the designing of armored vessels, in which he was much engaged, was "a branch of naval construction of much too concrete and ponderous a character to admit of any dalliance with abstract or fancy forms." He went on to express his regret, that owing largely to the restrictions which granite docks imposed upon naval constructors, and to the absence of iron floating docks capable of receiving ships of any form, and owing to other causes likewise, the construction of armored ships-by which he meant ships which had a sufficient volume protected above the water to keep them afloat and upright while the armor remained intact had been abandoned, and the first place upon the sea had been offered to any nation which had the courage and the will to assume it. In his opinion, this was a purely voluntary abandonment, and was not the result of any scientific or economic necessity. He admitted that great changes in forms and proportions were very desirable in our great line of battleships for example, a great increase of breadth was necessary in order to economize the side-armor, and to keep the ram and torpedo at ample distance from the boilers and magazines, which should be protected by an inner citadel, so to speak, well removed from the outer one. But, so far was true science from presenting obstacles to these and other important changes, it actually invited these very changes; and increase of beam in particular had been shown by Froude to facilitate the attainment of practical invulnerability combined with very high speed. Size and cost were among the bugbears of our naval administration: by the true engineer they were always regarded as secondary to great and noble objects, among which objects he included the naval pre-eminence of England. At any rate, there was no engineering

obstacle whatever to England constructing and sending to sea, not merely those great and swift, but delicate and fragile, Atlantic hotels in which the British navy was to embark and fight, for the want of something better, but also war-ships, real war-ships, capable of bearing the once proud flag of England boldly into the waters of any enemy whatever.

BONE-CAVES IN WALES.

FROM a careful study of the bone-caves in Wales, Dr. Henry Hicks (Proc. geologists' association, vol. ix. No. 1) makes some very important conclusions in regard to the contents of the caverns. The evidence shows that the area of North Wales was subjected to very great physical changes during pleistocene times. In the earliest part of the period it was raised to a considerably greater elevation than it is at present, and depressed afterwards in interglacial times to a depth of at least two thousand feet, so that it became a mere cluster of islands. After that, the area gradually rose again, with slight oscillations of level, until it attained its present configuration. Deposits relating to all these changes are to be found either on the Welsh hills or in the valleys, especially in those surrounding the Vale of Clwyd. If an attempt is made to correlate the deposits in the caverns with the glacial drifts of the neighborhood, the results of the changes referred to, one would be inclined to look upon the lowest drift in the caverns, that consisting mainly of local materials, as belonging to an early part of the glacial period, i.e., before the great submergence. Possibly this material was introduced into the cavern when the river flowed in the valley at a much higher level than at present, as it has much the appearance of that usually brought down by riveraction. As time went on, and the valley became deepened, so that the caverns were above the reach of the floods, they probably became the abodes of hyenas and other beasts of prey, or places where animals retired to die. During the epoch of great submergence, as soon as the caverns were on a level with the sea, they were probably filled with sand, and the animal remains became entombed in them. This sand is now found in the cavities of the bones, and occasionally cemented to them. In the period of upheaval which followed, as soon as the water was again on a level with the caverns, it washed out most of the sand, and carried in with it, instead, the muddy and other materials which had been deposited in the neighborhood by floating ice. By this means there was produced a general re-arrangement of the contents of the caverns. It was as the waters receded that the upper bowlder-clays were deposited both in the valleys and caverns. The abundance of bones in the caverns, and their very rare occurrence in the bowlder-clays of the valleys, prove almost conclusively that they must have been accumulated in the caves, and not washed in from the bowlder deposits near by. The proof furnished that the bones must have been buried in a marine sand before they were enclosed in the present cave-earth, is strong evidence

that the animals occupied the cavern in very early glacial times. Whether man also lived in the area at so early a period, cannot at present be decided by any evidence, as the flint implement found with the bones in Cae Gwyn Cave might have been introduced at a later period. It is, however, interesting to know that it appeared to be associated with the reindeer remains, and that the type is supposed to characterize what is called in France the reindeer period.'

AN EDIBLE CLAM INTRODUCED ON THE ATLANTIC COAST.

It

AN interesting shipment of shell-fish has just been received at the Wood's Holl (Mass.) station of the U. S. fish-commission. It consists of nearly eight hundred living specimens of Tapes staminea from the shores of Puget Sound, in Washington Territory, where it is known as the 'little round clam.' is not unlike the quahaug (Venus mercenaria) in general appearance, though differently ornamented, and not growing so large, and, as in the latter species, the valves fit closely together all around when the shell is closed. This clam is one of the most highly prized of the west-coast species, of which there are several used as food. It is marketed in large quantities in all of the principal towns, and would form a valuable addition to the food-products of the Atlantic coast, if it could be made to thrive here.

The shipment was made in one of the fish-commission cars, in charge of Mr. George H. H. Moore, and was obtained at Henderson's Bay, near Tacoma, Washington Territory, where the clams live on sandy and gravelly bottoms about the level of low tide. Between four thousand and five thousand specimens were secured, and first packed in wet sand, in the large stationary tanks on both sides of the car, filling a space about twenty-four feet long by two feet wide. The sand was moistened twice a day with sea-water at a temperature of about 56° F. During the first four days not over fifty of the clams died; but at the end of that time, as they were evidently not doing well, they were taken from the sand, and kept for a few hours in pure sea-water.

Then they were transferred to a bed of sand in which the shells were laid with the ventral margin uppermost, and covered with rock-weed which was kept constantly wet. During the next two days the mortality was very great, and it was thought best to try the salt water again. They were accordingly placed in tin cans of sea-water, in which they completed the rest of the journey, arriving at Wood's Holl, Friday, June 26, about seven days from the time of leaving Tacoma, where, however, they had been kept in the tanks two or three days before starting. On the last day of the trip, over seven hundred were lost, and the exact number received at Wood's Holl was seven hundred and sixty-eight. These were transferred to a suitable sandy beach, into which many began to burrow at once. It is impossible to predict how many of those brought over will recover

AFTER the investigation of the physical features of the world of the sea, it was expected and has proved that the greatest additions to our knowledge would be made by the expedition in the direction of biology. From the summaries furnished by the specialists engaged on the various monographs, and printed at intervals in the text of these volumes, a few facts may be cited in the endeavor to give an approximate idea of the scope and character of the results.

The main purpose of the expedition, on the biological side, was to investigate the marine life of the sea, and incidentally to examine the life of certain isolated oceanic islands, - faunae pregnant with meaning for the naturalist, though scanty in species or individuals. Both objects were carried out in a manner satisfactory to naturalists, and creditable to the officers of the expedition. The air-breathing vertebrates, of course, were little sought after, but interesting observations are recorded on the sea-elephant and fur-seal; and the bones of cetacea dredged from the sea-bottom were sufficiently numerous and interesting to justify a special report on them by Professor Turner. The expedition seems to have needed a live harpooner, for it got no porpoises during the whole voyage, though many played about the ship. The birds collected, though not extremely numerous, were of great interest, and have been reported on by Dr. Sclater, the Marquis of Tweeddale, Dr. Finsch, Count Salvadori, Messrs. Saunders, Salvin, and Garrod. The death of the latter prevented the completion of his work on the anatomy of the petrels, which was taken up by the late W. A. Forbes, who made an exhaustive report on the subject, showing that the order of Tubinares must be divided, as proposed by Garrod, into two very distinct families characterized by numerous and important differences, which indicate not only a great antiquity for the whole group, but a great amount of extinction among its past members, in the process of which nearly all

the intermediate or less specialized forms are believed to have disappeared. Professor Cunningham has reported on the marsupial mammals; Professor Parker, on the development of the green turtle; and Professor Turner, on the human crania collected during the voyage. The report on the deep-sea fishes, by Dr. Günther, is still a desideratum, but will unquestionably be of great interest. Some preliminary notes appear in this volume. A great similarity between the fish fauna of the Japan seas, the West Indies and adjacent Atlantic Ocean, and the Mediterranean, is clearly shown. At St. Paul's Rocks a new species of Holocentrum was found, but the fish fauna had a generally Antillean character. A remarkable fish, Bathypterois, was found on the coast of Brazil, with rudimentary eyes, and part of the pectoral fins modified to form extremely long tactile filaments. Another, Ipnops, dredged in the ocean at a depth of 1,900 fathoms, had the eyes modified to such an extent as to resemble two scale-like plates on the top of the much-flattened muzzle. No image can be formed in them, but they may serve for detecting minute quantities of light. Still another, Echiostoma, has eyes and formidable teeth, with long filaments extending from the chin and pectorals. A series of luminous globular bodies extends along the lower part of the body, and others of larger size are found on the head. The bones and ligaments of the deep-sea fishes are very soft, and the muscles loosely connected with each other. This is partly due to the expansion which they undergo in being raised quickly from regions where the water permeating all their bodies is under immense pressure; but the tissues must be loose to admit of such permeation, or they would be crushed and ruined under a weight which shivers solid glass to powder. Many of them are blind; many of them have phosphorescent organs, or secrete a phosphorescent slime; others have distensible stomachs and wide mouths, which ingulf fishes much larger than themselves.

Turning to the division of invertebrata, we find ourselves more than embarrassed with riches. The mollusks being in the hands of Rev. Boog-Watson and Mr. E. A. Smith of the British museum, who have so far submitted only preliminary notices, we learn chiefly of some special rarities, such as the paper-thin volute, Guivillea, from the depths of the Southern Ocean, or the beautiful Pecten Watsoni, of the section Amussium. Mr. Smith reports, in harmony with the results of the Blake expedition, that among the bivalves dredged from a depth of over 2,000 fathoms