them.

world, had been the scene of operations, and the results, though not all that could be desired, are nevertheless well worthy of the time and money expended in obtaining M. Andrè, of the Paris Observatory, a well-known French astronomer, was appointed director of the expedition, whilst to M. Angot, Professor of Physics in the Normal School, Paris, the photographic portion of the work was entrusted. The instruments to be used consisted of five telescopes of various powers; a very complete photographic apparatus which will be described hereafter; a meridian instrument; an apparatus for producing an artificial transit, with electric chronograph carrying four pens attached; and lastly, two instruments for accurately determining the magnetic inclination and declination of Nouméa, which up to the present time have never been exactly known. The largest of the telescopes (75 in.), as well as three others (5 in.), was provided with an objective silvered by M. Foucault's process, the fifth having an unsilvered lens of 3 in. diameter, and of extremely good definition. All the instruments were equatorially mounted, three of them being connected with the chronograph, whilst the other two obtained their time by means of clock and chronometer. The telescope used for the photographic part of the work had an objective of 5 in. diameter and 13 ft. focal length, and was firmly fixed in a horizontal position on stone pillars, the image of the sun being directed along the axis by a large silvered mirror placed outside and moved at will from the interior by means of long wooden rods on either side of and parallel to the telescope. During the transit an assistant stood near this mirror, and at every command “Découvrez," removed the cover (placed on the mirror to prevent it becoming heated, and thereby causing distortion of the sun's image), and replaced it immediately after the plate had been exposed. With this apparatus, the daguerreotype process of sensitising a silvered plate of copper by means of iodine and bromine, developing in a mercury bath and fixing with hyposulphite of soda, was alone employed, and with the greatest success.

Though the day was somewhat cloudy, considerably over 100 very well-defined pictures of Venus during the Transit were obtained, together with 130 others, rendered less distinct by the intervention of clouds. When it is known that for several days previous to the 9th, the weather had been so bad that all hopes even of a glimpse of the transit of the planet were abandoned, and that dense clouds hung over the whole sky, and heavy showers of rain fell up to within four hours of the first contact, M. Angot may well be congratulated on the success of his labours. These daguerreotype pictures are not quite 1 in. in diameter, and were obtained by exposures of the plates varying from too of a second in duration. M. Janssen's method was not employed, but a very simple plan was adopted of placing the sensitised plate in a frame fixed at the focus of the chemical rays, and causing the exposure by sliding in front of it a metallic screen with a slit in it, whose width of course varied with the time necessary for exposure. A clock connected electrically with the sidereal one in the main observatory was placed in a convenient position above the telescope, and the instant of each exposure accurately noted. The assistants in this work, four in number, were all convicts, who performed their share with the neatness and readiness for which Frenchmen, whatever their position in life may be, are so remarkable; and, indeed, nothing has struck me more during the progress of the work here than the aptitude which seems innate in the French race for work of this kind; and it is no disparagement to English soldiers to say that it would have taken them days to learn to read chronometers with the accuracy which their French brethren-in-arms acquired in a few hours and apparently without the slightest difficulty. The main features in all the telescopic observations are the

3 minutes' difference between the estimated and observed times of first contact, the absence of the drop, and, in the case of the instruments furnished with silvered objectives, the clear tangential contact of the planet and the sun's limb, which enabled four out of the five observers to obtain the instant of second contact with very great accuracy. With these objectives, which appear to be espe cially well adapted for observations of this nature, the planet was seen to pass clear and distinct on to the sun's disc, without any appearance of distortion or cloudiness whatever; but with the unsilvered objective an appearance was observed as if a drop, such as those described by English astronomers, was about to form. Without forming, however, it changed almost imperceptibly into a tremulous haziness, which rendered it impossible to say when the actual contact took place, and compelled the observer to note two instants, one when this haziness first appeared, and the other when it had so far disappeared in the increasing brightness in the rear of the planet that he was confident that Venus was fairly on the solar disc. These two instants are separated by an interval of thirtyfour seconds, and their mean corresponds within two or three seconds with the instant of tangential contact observed with the other instruments. Whether the slight cloudiness of the sky, or a constant error peculiar to all unsilvered objectives, or the fact that the latter telescope was focussed on a spot much nearer to the sun's limb than the other instruments, is to be put down as the cause of this difference or not, seems at present a matter of doubt only to be cleared up when other observations with unsilvered lenses are recorded.

The third and most important contact in New Caledonia was not observed, owing to a cloud which, much to our chagrin, strayed over the sun's face some 6' before the estimated time of egress, and completely shut out our view for about 20', after which the fourth contact was observed, but with a considerable degree of uncertainty, on account of the undulatory appearance of the sun's limb.

I may mention, in conclusion, that the times of duration of the whole transit, ie. the interval between the first and fourth contacts, obtained by three of the observers, differed by only 8", but these were considerably at variance with the estimated duration of the transit as given in the Nautical Almanac. Besides MM. Andrè and Angot, three French officers, Capts. Derbés, Bertin, Ribout, and Mr. Abbay, took part in the observations. A. On board the Rangatira,

Jan. 5, 1875

SCIENTIFIC REPORT OF THE AUSTRO-HUNGARIAN NORTH POLAR EXPEDITION OF 1872-74 *

THE real object of the expedition was not particularly that of large unknown sea north of Siberia; the explorers thought they reaching high latitudes, but rather the investigation of the might eventually reach Behring's Straits, without cherishing very precht made a preliminary expedition into those regions, he sanguine hopes on this point. When during 1871 Lieut. Weyfound the whole large sea between East Spitzbergen and Nowaja Semlja so completely unknown, that in spite of his stopping six weeks at Tromsö, and making inquiries of all Finnmark skip. pers and whalers, he could not learn anything definite as to the conditions of climate and ice in those parts; few vessels had succeeded in reaching the 76th degree of north latitude. During the two Austrian expeditions this unknown sea has been investigated from 40° to 70° East long. (from Greenwich), and beyond the 79th degree of latitude on the west side and the Soth on the east side; an extensive, hitherto unknown tract of land has been discovered, and Lieut. Julius Payer has made sledge journeys into this land, reaching very nearly 83° N. lat.

In 1871 the explorers had found the sea completely free from * Die 2. Oesterr. -Ungarische Nord Polar Expedition unter Weyprecht und Payer, 1872-74. (Petermann's Geogr. Mittheilungen, 1875; heft h.)

breaking. This, however, is only the case with new ice, as after a short time the salt crystallises out of the ice, and the surface covers itself with a snowy layer of salt, sometimes reaching two inches of thickness. Even in the most intense cold this layer retains so much moisture that it makes the impression of a thaw; only little by little, evaporation and drizzling snow do their work, and the ice itself becomes brittle.

In this way almost all the salt, which was frozen in, crystallises out, and is washed off and back into the sea by the melted water in the next summer. The melted water at the end of the summer is therefore almost free from salt, and has a specific gravity of 1005. It is evident that a smooth plane of ice, as is found on sweet water, is a very rare occurrence in Arctic regions. The finest and most interesting phenomenon, the only change in the long night of winter, is the Aurora Borealis ; no pen can describe the magnificence of this phenomenon in its greatest intensity. In February 1874 Lieut. Weyprecht saw an aurora, which ran beyond the zenith from east to west like an immense stream of fire, and constantly showed intense prismatic colours running like flames, and as quick as lightning, from one side of the horizon to the other. At the same time flashes of fire came from the southern horizon and reached to the magnetic pole; it was the most stupendous natural display of fireworks he had ever been able to imagine. With regard to the intensity of the aurora, Lieut. Weyprecht says he can prove by data that it differs, independently of the geographical latitude, in the different parts of the Arctic zone, and that the district he visited was a maximal district; when the sky was clear, traces of auroræ could be uninterruptedly observed; in the second winter he even kept aurora journal," which, however, gave only few positive results, and was left behind in the ship. The phenomenon is past all description and classification, changing constantly and showing new forms at every moment. Lieut. Weyprecht was never able to describe the origin of an aurora; the phenomenon is there, and it is impossible to say whence it came.

an

Only in a very general way three forms of aurora can be distinguished: first, quiet, regular arcs, slowly passing from the southern horizon and disappearing in the northern one; then, bands of light of great variety of forms, ever changing place and intensity; and lastly, the so-called corona, i.e. radiations from or towards the magnetic pole. Generally the colour is an intense white with a greenish hue; with greater motions and stronger radiations the prismatic colours are often seen in great intensity.

Lieut. Weyprecht spent much time and trouble on spectral

observations of the aurore, but unfortunately his spectroscope was too small and imperfect. He could never see more than the well-known green line; compared with the spectral observations of the Swedish Expedition, which were made with much more perfect instruments, his observations are of no value. One interesting fact with regard to the aurore was, however, ascer tained. It was found that upon very intense aurora storms followed almost every time; this is proved by meteorological data, and Lieut. Weyprecht thinks he is justified in the conclusion that the Aurora Borealis is an atmospheric phenomenon and closely connected with meteorological conditions; he arrived at this conviction through observing hundreds of aurore, but says he cannot give any positive or important reason for his conclusion. (To be continued.)

JOHN EDWARD GRAY, F.R.S.

WE E have to record the death, on Sunday morning last, at his residence in the British Museum, of Dr. J. E. Gray, late Keeper of the Zoological portion of the National Collection.

Dr. Gray was born in 1800 at Walsall, in Staffordshire, being the eldest of the three sons of Mr. S. F. Gray, a chemist of that town. He was educated for the medical profession, and very shortly exhibited his biological taste, by writing a work on the then new "natural" arrangement of plants. In 1824 Dr. Gray was appointed an assistant in the Natural History department of the British Museum, where, with the assistance of Dr. Leach, he commenced the study of zoology to such good purpose that in 1840 he succeeded Mr. Children as Keeper of the Zoological Collection of the Museum. At that time biology held but a small place in popular favour, especially in the eyes of those most active in the superintendenc of

the extension of the British Museum. Against the opposing influences thus affecting his department, not the least of which was the antagonism of Mr. Panizzi, Dr. Gray, by his indefatigable zeal and courage to face obstacles, nevertheless succeeded in bringing the national collection of osteological and skin specimens, during the thirty-five years of his keepership, to so high a standard of excellence, that no other museum, not even Leyden itself, is equal to it.

Most of the biological societies which now exist include Dr. Gray amongst their founders or earliest members. The Zoological Society owes much to him, the number of papers communicated to it by him being very great. He was the leading spirit of the Annals and Magazine of Natural History, and was the author of the Zoological Miscellany, Knowsley Menagerie, and other works. In his Catalogue of the Mammals in the British Museum, which is far advanced towards completion, is incorporated much of the author's work in that direction, published originally in separate short papers.

The qualities which most distinguished Dr. Gray as a naturalist were his great industry in combination with an acute perception of minute distinctions. His imperfect acquaintance with anatomy in many of its branches much limited his generalising powers, and in some cases distorted his view of the relative importance of character based only on osteological features. To all students of the groups of animals which were touched upon by Dr. Gray-and there are but few that were not-that author's work will be found invaluable, both from the independent light which it throws on the subject, and from the careful review which it gives of the previous investigations of other naturalists.

Dr. Gray was elected a Fellow of the Royal Society in 1832; he resigned the Keepership of the British Museum at Christmas last. He leaves a widow, but no children.

NEW ORDER OF EOCENE MAMMALS

AT the last meeting of the Connecticut Assembly, February 17, Prof. O. C. Marsh made a communication on a new order of Eocene Mammals, for which he These animals are proposed the name Tillodontia. among the most remarkable yet discovered in American strata, and seem to combine characters of several distinct groups, viz., Carnivores, Ungulates, and Rodents. In Tillotherium, Marsh, the type of the order, the skull has the same general form as in the bears, but in its structure resembles that of Ungulates. The molar teeth are of the ungulate type, the canines are small, and in each jaw enamel, and growing from persistent pulps, as in Rodents. there is a pair of large scalpriform incisors faced with The adult dentition is as follows:-Incisors; canines

I

; premolars; molars 3. The articulation of the

lower jaw with the skull corresponds to that in Ungulates. The posterior nares open behind the last upper molars The brain was small, and somewhat convoluted. The skeleton most resembles that of Carnivores, especially the Urside, but the scaphoid and lunar bones are not united, and there is a third trochanter on the femur. The radius and ulna, and the tibia and fibula are distinct. The feet are plantigrade, and each had five digits, all terminated with long, compressed and pointed, ungual phalanges, somewhat similar to those in the bears. The other genera of this order are less known, but all apparently had the same general characters. There are two distinct families, Tillotherida, in which the large incisors grew from persistent pulps, while the molars have roots: and the Stylinodontida, in which all the teeth are rootless. Some of the animals of this group were as large as a Tapir. With Hyrax or the Toxodontia the present order appears to have no near affinities.