way are open for traffic, while over 2000 miles of line are in course of construction. Applications for space must be made before the end of August this year. The Commission desires to make the Exhibition specially interesting in manufacturing processes, machinery, &c., in motion, and objects of manual labour. There will also be a picture gallery lighted by electricity. Further information may be obtained from the AgentGeneral in London, or from the Executive Commissioners in Melbourne.

MR. ROBERT ETHERIDGE, JUN., of the Geological Department of the British Museum, has received the combined appointments of Paleontologist to the Department of Mines, and to the Australian Museum, Sydney, and will shortly proceed to Australia to take up the duties of the two offices. His extensive palæontological knowledge will be much missed in the British Museum.

SOME days ago the Medical School of Paris elected M. Brouardel as Dean, in the place of M. Béclard, recently deceased. M. Brouardel is Professor of Forensic Medicine.

ON Saturday last Mr. John Morley delivered, in the Egyptian Hall of the Mansion House, the annual address to the students of the London Society for the Extension of University Teaching. His subject was "The Study of Literature," and we need scarcely say that he set forth his ideas with his usual vigour and lucidity. But what did Mr. Morley mean by the following sentence: "I, for one, am not prepared to accept the rather enormous pretensions that are nowadays made sometimes for physical science as the be-all and end-all of education"? By whom are these "rather enormous pretensions" made? Men of science, no doubt, claim for the study of physical science a high place in education; but we have never heard that they feel disposed, on that account, to exclude the study of art and literature.

THE University of St. Petersburg lately celebrated its sixty. eighth anniversary. It has 64 professors, 47 fellows, 8 lecturers, and 39 laboratory assistants. There are 2627 students, who are grouped as follows:-For Oriental languages, 87; for law, 1170; for natural science, 426; for mathematics, 618; for history and philology, 224.

We have received the four February sections of "Studies in Microscopical Science," edited by Mr. Arthur C. Cole. The text, which is finely illustrated, relates to Haustoria, the ovary and ova in birds, fatty degeneration of the kidney, and microbes.

PROF. OTTO STRUVE'S jubilee was celebrated some days ago at the Pulkowa Observatory. A great number of delegates from learned societies and scientific institutions were present.

THE new journal edited by Prof. Grancher is called the Bulletin Médical. It appears in Paris twice a week, on Thursdays and Sundays.

In the February number of the Journal of the Anthropological Institute there is an interesting paper by Mr. Bloxam, describing eight specimens of Aroko or symbolic letters, which have actually been used by the tribe of Jebu in West Africa. These Aroko were sent to Mr. R. N. Cust by Mr. J. A. Otonba Payne, Registrar of the Supreme Court at Lagos, who himself belongs to the tribe of Jeba. The paper is carefully illustrated. One of the figures represents a message from a native prince of Jebu, Ode, to his brother residing abroad. It consists of six cowries, all turned in the same direction. The quill of a feather is passed through them from front to back, and the shaft is turned towards the end of the quill and fixed to the side of the

cowries. The significance of this symbolic group of objects depends upon the facts that, in the Jebu language, six is "E-fà," from the verb "fa," to draw, and that Africans are in the habit of cleansing their ears with a feather, and look upon it as the only instrument by which this can be effectually done. The meaning is: "By these six cowries I do draw you to myself, and you should also draw closely to me; as by the feather only I can reach to your ears, so I am expecting you to come to me, and hoping to see you immediately."

In the Rendiconti of the Reale Istituto Lombardo for January, Count Trevisan de Saint-Léon describes some experiments recently carried out by Dr. Bareggi in Milan, for the purpose of showing that it is possible to ascertain, from the state of the blood, whether persons bitten by animals suspected of rabies, or even undoubtedly mad, have really been infected.

THE Reports of the Botanist to the New York Agricultural Experiment Station, Geneva, N.Y., Mr. J. C. Arthur, for 1885 and 1886, furnish an admirable illustration of the value of such State appointments. A large portion of both Reports is occupied with an exhaustive history of the pear-blight (Micrococcus amylovorus), which is exceedingly destructive to pear-trees in the Northern United States; proofs that the mis chief is caused by the specific Bacterium; and suggestions for a remedy. In addition to this, much information is given with regard to the following diseases, among others: the strawberrymildew (Spharotheca Castagnei), the plum-leaf fungus (Septoria cerasina), the lettuce-rust (Septoria Lactuca), and the lettucemildew (Peronospora gangliformis). Woodcuts are given of these various fungoid parasites, and a very useful summary is appended of the literature of the pear-blight.

AN admirable lecture on Wrought Iron" was delivered by Mr. J. Starkie Gardner at the Society of Arts on Tuesday, February 22. It is printed in the current number of the Journal of the Society of Arts, with illustrations of the exquisite ironwork in the cathedrals of York, Durham, and Winchester. The general artistic superiority of medieval ironwork to that of later times Mr. Gardner attributes in part to the fact that in the Middle Ages important work of this kind was intrusted only to smiths who had a special aptitude for it. If such a workman was not forthcoming, the work was either not executed, or was made in the simplest form; whilst, if he were forthcoming, the details at least of the design were left to his own fancy. Mediæval smiths were not fettered by estimate or bound by time, but Mr. Gardner is of opinion that they did their work much more quickly than men do now. Otherwise, he thinks, the intricate designs used in Germany, Spain, and Portugal, for ordinary domestic purposes, could not have been produced at any price which would have suited the occupiers.

AT a durbar held at Shillong in connection with the Jubilee rejoicings, Mr. Ward, Chief Commissioner of Assam, reviewed the history of the province during the last fifty years. In that time, he said, its population and settled area had been nearly trebled. The first tea plantation had been started about fifty years ago. There were now nearly 200,000 acres under tea, while the land taken up by planters, although not yet actually planted, amounted to about 400,000 acres. Again, fifty years ago the land revenue of five districts, comprising Assam proper, had been about four and a half lakhs of rupees; it had grown to twenty-six lakhs. Then the journey from Gowhatty to Debrooghur had occupied a month or six weeks; now it took three days.

MUCH interest has been excited by the announcement that Capt. Conder, of the Palestine Exploration Expedition, has succeeded in deciphering and translating the Hittite inscriptions. Ten principal texts are known, and Capt. Conder claims to have

intepreted all of them. Three of his translations, which were published in the Times of Saturday last, are invocations to the sun and water gods, and, apparently, to the divinity of the moon. Capt. Conder says that not only the words, but the grammar of the inscriptions, can be shown to belong to a wellknown tongue. What this tongue is, we are not to learn for some time.

WE regret to announce the death of Dr. Grothe, Professor at the Polytechnical School at Delft, author of "Mechanical Technology," and an excellent monograph on iron. He was born in Westphalia in 1806, and died on February 10 last.

PROF. HAECKEL, of Jena, has just started on a journey to the East, which will be of some months' duration. He will visit the coast of Asia Minor to continue his investigations of lower marine animals.

LIEUT. QUEDENFELDT has just returned from Morocco to Berlin, bringing with him some valuable collections: an ethno. logical one, which he has presented to the Anthropological | Society, a collection of insects, and a large collection of the implements, tools, and instruments of torture of the Hamadjas

tribe.

MESSRS, G. PHILIP AND SON have in the press a revised and enlarged edition of "The Geology of England and Wales," by Horace B. Woodward, F.G.S., of the Geological Survey of England. They will also have ready shortly "Philips' Plani. sphere of the Stars visible from the Countries situated about 35° south of the Equator" (uniform with "Philips' Planisphere for England"); "Rustic Walking Routes within the Twelve-mile Radius from Charing Cross," containing a fieldpath map of the district, with geographical description, charts, and directions, by W. R. Evans; and "Philips' Handy Volume Atlas of the World," consisting of sixty-four plates, containing upwards of one hundred maps, printed in colours, with statistical notes on each map.

MESSRS. WHITTAKER AND CO. will publish shortly a second and much enlarged edition of "Magnets and Dynamo-Electric Machines," being the first volume of their "Specialist's Series." For the new edition some revisions in the text have been made, and a preface and a chapter on the latest types of generators have been written by Mr. W. B. Esson.

A FRENCH translation has been published of Cæsar Lumbroso's "Uomo Delinquanti," with a fine series of figures to illustrate the learned author's lectures concerning the anthropological features of the professional criminal.

ADMIRAL TEISSERENC DE BORT has just published a map, showing the distribution of fog on the various parts of the earth. It is based upon observations made at 1600 land stations, and 112,000 marine ones.

IN a Report just issued, Mr. S. W. North, Medical Officer of Health, calls attention to the prevalence of typhoid fever in York during the year 1886. For many years York has been liable to outbreaks of this disease, and the fact will not surprise anyone who reads Mr. North's account of the sanitary conditions of the city.

IN a paper entitled "Ueber die Allgemeine Beugungsfigur in Fernröhren" (Mémoires de l'Académie Impériale des Sciences de St. Pétersbourg, viie. série, tome xxxiv., No. 5), Hermann Struve remarks that the old problem of the diffraction of light through a circular aperture, the source being in the axis, has been considered by Airy and others, who have given approximate solutions in special cases; but the general solution has only been made feasible by the discovery of Bessel's functions. He accordingly proceeds to develop it by the straightforward methods with which readers of modern analysis are familiar;

showing how his solution accords with those previously given for the axis and for the edge of the geometrical shadow. In this latter case he remarks that the illumination is less than onefourth that which would be obtained by removing the screen. Ilis results are put into a useful numerical form in tables at the end of the paper.

THE last number of the Bulletin of the Belgian Natural History Museum contains a summary of ornithological observations made at various stations throughout Belgium during the year 1885. This is quite a novel feature, which, if carried out systematically, promises excellent results, especially as regards the many obscure questions connected with the migrations of birds of passage. The chief stations are Brussels, Hasselt, Carlsburg, and the Ostend and other lighthouses along the coast. The names of the naturalists who undertake to send in reports are given in all cases. These reports contain the name of the bird in three languages-Latin, French, and Flemish or Walloon according to the locality-followed by the dates of arrival and departure, and any other remarks tending to throw light on the habits and movements of the bird. Thus, under Ciconia alba, Bechst., Cicogne blanche, Ooievaar (white stork), we have, from the Nieuport Lighthouse: "Seven seen, June 18, flying westwards; rare on this coast, where they never nest. -Signed, A. Vermorke." The present summary contains 171 such entries, the value of which, when made by competent observers from year to year, ornithologists will not fail to appreciate.

THE latest advices from Honolulu report that the volcano of Mauna Loa is again in eruption, and that all the craters in the vicinity have become active.

In the December number of the Mineralogical Magazine, Prof. Macadam gives the analysis of a sample of talc used in paper-making. This mineral is obtained from New Jersey. It is very largely employed for paper-making in place of China clay (kaolin), and gives, amongst other advantages, a much more pure effluent, fully 90 per cent. being retained in the paper. From its fibrous nature it appears to attach itself to the smaller paper particles, and retain these also. The very high and beautifully smooth glaze of the American papers is largely due to the use of this substance.

In the Mittheilungen of the Zürich Antiquarian Society (Band xxii. Heft 1) will be found a detailed account of the recently-discovered lake-dwelling at Wallishafen, on the Lake of Zürich. The articles found were mainly bronze, but underneath the existing remains appear to be the charred fragments of an earlier dwelling, the remains of which clearly belong to the Stone Age.

A LARGE canoe, belonging to prehistoric times, was lately dragged from the bottom of the River Cher, near Vierzon, and is now in the Museum of the Society of Antiquaries at Bourges. A part of it had been visible for many years at low water, but no one understood what it was until it happened to be seen by M. Beauchard, who at once perceived its real character. When it was brought to land, fragments which had been torn or cut off by peasants were recovered and pieced together. The canoe is in the form of a trough, and is said to have a general resem. blance to the ancient boat found some time ago at Brigg, in Lincolnshire. The present specimen has the special characteristic of being closed at both ends by pieces of wood fixed in vertical grooves. This device seems to have been adopted in consequence of the boat having been injured by some accident.

M. GUILMETH, the French traveller, while on a journey in Australia, discovered some bee-hives in a gigantic eucalyptustree, of 120 metres in height. The honey was strongly scented with the perfume of the flowers of the tree. Prof. Thomas Karaman has examined it, and believes it to have beneficial medicinal properties.

LIKE the authorities of the National Museum, Washington, the Curators of the Museum of the Academy of Natural Sciences, Philadelphia, complain that they have not nearly room enough for the display of the collections intrusted to their "It is well within the truth," they state in their charge. Report for 1886, "to say that the existing collections, if properly displayed, would completely fill a building of twice the dimensions of the present one. The large and very valuable collections of the Pennsylvania Geological Survey, contained in upwards of 200 cases, still remain in the cellar, boxed, for want of exhibition space. The types of the greater number of the fossil plants described by Lesquereux in his 'Coal Flora of the United States,' probably one of the most valuable collections of fossil plants in the world, have been added to this collection during the year, but, for similar reasons, still remain boxed. The report of the Professor of Ethnology and Archæology indicates that accessions to this department of the Academy's Museum could readily be had were proper exhibition space provided, but that under present conditions the same is impossible. In view of these facts the necessity for an extension to the Academy's building cannot be too strongly insisted upon." The Curators also urge that a fund should be raised for zoogeographical exploration. The interest derived from 50,000 dollars would, they think, fairly equip an annual expedition to any of the largely-unexplored regions lying about the dominions of the United States, such as Mexico, Central America, the Bahamas, and Labrador.

MR. ARTHUR J. BETHELL has reprinted, with additions and corrections, three articles which lately appeared in the Field, on a ride to the Falls of Zambesi. He has added a number of notes which may be of considerable service to men who think of spending some time in hunting in South Africa.

IT was decided some time ago that a number of the Crown diamonds of France should be sold. Others were put aside for the collections of the Paris School of Mines and Museum of Natural History; and these gems were recently given to the delegates appointed by the two Schools. The Regent diamond, a very fine one, will be kept in the Louvre Gallery.

ated

THE additions to the Zoological Society's Gardens during the past week include a Bonnet Monkey (Macacus sinicus), a Macaque Monkey (Macacus cynomolgus) from India, presented by Miss E. James; a Three-striped Paradoxure (Paradoxurus trivirgatus) from India, presented by Mr. Gerald Callinder; a Common Squirrel (Sciurus vulgaris), British, presented by Miss May Honrott; a Scop's Owl (Scops qui), captured at sea near Aden, presented by Mr. W. M. Holland; a White-fronted Heron (Ardea nova-hollandia) from Australia, presented by Mr. J. B. Dyas; a Stanley Parrakeet (Platycercus icterotis) from West Australia, a Burmeister's Cariama (Chunga burmeisteri) from South-East Brazil, a Black Sternothere (Sternothærus niger) from West Africa, received in exchange; two Smews (Mergus albellus 88), European, purchased.

OUR ASTRONOMICAL COLUMN

3 56.7 3 400 3 26.5

Decl.

Brightness

29 21 Ν. 31 18 32 48 Ν.

0.38

0'32

The brightness at discovery is taken as unity.

A METHOD FOR THE DETERMINATION OF THE CONSTANT OF ABERRATION.-M. Lœwy, in reply to M. Houzeau's claim to be considered the originator of the method for determination of aberration by measurement of the relative positions of two stars situated in distant parts of the sky (NATURE, vol. xxxv. p. 377) points out, in the Comptes rendus, tome civ. No. 7, that the invention of a new method for the determination of the constant of aberration does not consist in a general indication of the effect of aberration on a certain observation or combination of observations, but in furnishing definite rules the following out of which will lead to results of the accuracy demanded by the exigencies of modern science. M. Lœwy maintains that M. Houzeau's researches on the subject come under the former category, whilst his own are entitled to be ranked under the latter.

The same number of the Comptes rendus contains a note by M. Trépied pointing out how photography can be applied for the purpose of practically carrying out M. Lewy's method.

THE HARVARD COLLEGE OBSERVATORY.-From Prof. Pickering's Report, presented on December 7, 1886, we learn that during the past year the east equatorial has been used for the photometric observation of the eclipses of Jupiter's satellites upon the system adopted in 1878. The total number of eclipses thus observed is 358, of which 39 have occurred since the end of October 1885. With the same equatorial the observation of comparison stars for variables with the wedge photometer has been continued, and has formed the principal work of the instrument. The "new" stars in Orion and Andromeda, and comets, have also been observed with the east equa torial throughout the year. The reduction and publication of work already done with the meridian-circle is at present, in Prof. Pickering's opinion, more desirable than the prosecution of new series of observations. This department of the Observatory has sustained heavy loss in the resignation of Prof. Rogers, who has devoted many years to laborious astronomical work at Harvard College. During the year ending November 1, 1886, 209 series of measures have been made with the meridianphotometer. The total number of separate photometric comparisons is 59,800. The instrument continues to give entire satisfaction as a means of measuring the brightness of stars of the ninth

a

stars used as standards, which, with the smaller instrument of the same kind employed in the Harvard photometry, was 0.16 of a magnitude, has been reduced to 0.12 with the present instrument; whilst the average deviation of stars from the fifth to the ninth magnitude but little exceeds or of a magnitude. And a comparison between the results obtained by Dr. Linde mann, at Pulkowa, with a Zöllner photometer, and at Harvard College, with the meridian-photometer, shows that the average deviation of a measurement of the difference in brightness between two stars observed at both places does not exceed of of a magnitude. For an account of the interesting and import

Paper read before the Royal Society by Mr. Willian Crookes, F. R.S.,

ing under the excitement of the induction discharge in vacuo, I have found very great differences in the duration of the residual glow. Some earths continue to phosphoresce for an hour or more after the current is turned off, while others cease to give out the light the moment the current stops. Having succeeded in splitting up yttria into several simpler forms of matter differing in basic power (Roy. Soc. Proc. vol. xl. pp. 502-509, June 10, 1886), and always seeking for further evidence of the separate identity of these bodies, I noticed occasionally that the residual glow was of a somewhat different colour to that it exhibited while the current was passing, and also that the spectrum of this residual glow seemed to show, as far as the faint light enabled me to make out, that some of the lines were missing. This pointed to another difference between the yttrium components, and with a view to examine the question more closely I devised an instrument similar to Becquerel's phosphoroscope, but acting electrically instead of by means of direct light.

The instrument, shown in Fig. I, A and B, consists of an opaque disk, abc, 20 inches in diameter, and pierced with twelve openings near the edge as shown. By means of a multiplying wheel, d, and band, ef, the disk can be set in rapid rotation. At each revolution a stationary object behind one of the apertures is alternately exposed and hidden twelve times. A commutator, g (shown enlarged at Fig. 1, B), forms part of the axis of the disk. The commutator is formed of a hollow cylinder of brass round a solid wooden cylinder. The brass is cut into two halves by a saw cut running diagonally to and fro round it, so as to form on each half of the cylinder twelve deeply cut teeth interlocking, and insulated from those on the opposing half cylinder by an air space about 2 mm. across. Only one half, hhh, of the cylinder is used, the other, i ii, being idle; it might have been cut away altogether were it not for some little use that it is in saving the rubbing-spring, j, from too great friction when passing rapidly over the serrated edge. To a block beneath the commutator are attached two springs, one, k, rubbing permanently against the continuous base of the serrated hemicylinder hh, and the other, j, rubbing over the points of the teeth of hh. By connecting these springs with the wires from a battery it will be seen that rotation of the commutator produces alternate makes and breaks in the current. The spring, j, rubbing against the teeth is made with a little adjustment sideways, so that it can be said to touch the points of the teeth only, when the breaks will be much longer than the makes, or it can be set to rub near the base of the teeth, when the current will remain on for a much longer time and the intervals of no current will be very short. By means of a screw, 11, attached to the spring, any desired ratio between the makes and the breaks can be obtained. The intermittent primary current is then carried to an induction coil, m, the secondary current from which passes through the vacuum tube, n, containing the earth under examination. When the commutator, the coil-break, and the position of the vacuum tube are in proper adjustment, no light is seen when looked at from the front if the wheel is turned slowly (supposing a substance like yttria is being examined), as the current does not begin till the tube is obscured by an intercepting segment, and it ends before the earth comes into view. When, however, the wheel is turned more quickly, the residual phosphorescence lasts long enough to bridge over the brief interval of time elapsing between the cessation of the spark and the entry of the earth into the field of view, and the yttria is seen to glow with a faint light, which becomes brighter as the speed of the wheel increases.

To count the revolutions, a projecting stud, o, is fastened to the rotating axis, and a piece of quill, p, is attached to the fixed support, so that at every revolution a click is produced. With a chronograph watch it is easy in this way to tell the time, to the tenth of a second, occupied in ten revolutions of the wheel.

Under ordinary circumstances it is almost impossible to detect any phosphorescence in an earth until the vacuum is so high that the line spectrum of the residual gas begins to get faint; otherwise the feeble glow of the phosphorescence is drowned by the greater brightness of the glowing gas. In this phosphoroscope, however, the light of glowing gas does not last an appreciable time, whilst that from the phosphorescent earth endures long enough for it to be caught in the instrument. By this means, therefore, I have been able to see the phosphorescence of yttria, for example, when the barometer gauge was 5 or 6 mm. below

the barometer.

When the earth under examination in the phosphoroscope is yttria free from samaria, and the residual emitted light is ex