cella, Pseudorca, Globicephalus, Grampus, Feresia, Lagenorhynchus, Delphinus, Tursiops, Clymenia, Steno, and Sotalia. Critical remarks were added upon the characters and synonymy of the best-known species of each.-Prof. Flower also gave an account of a specimen of Rudolphi's Rorqual, Balaenoptera borealis, Lesson (= Sibbaldius laticeps, Gray), lately captured in the River Crouch, Essex, being the first well-authenticated example of this species met with in British waters.-A communication was read from Dr. M. Watson, F.Z. S., containing additional observations on the structure of the female organs of the Indian Elephant (Elephas indicus).—A communication was read from Mr. F. Moore, F.Z.S., containing the descriptions of some new Asiatic Diurnal Lepidoptera.-A communication was read from Mr. R. Trimen, F.R.S., in which he gave a description of a remarkable semi-melanoid variety of the Leopard (Felis pardus) in the Albany Museum, Grahamstown, which had been obtained in the east of the Cape Colony.-A communication was read from the Count H. von Berlepsch and Mr. L. Taczanowski, in which an account was given of an extensive collection of birds made by MM. Stolzmann and Siemiradzki in Western Ecuador.

EDINBURGH

Royal Physical Society, November 21.-The first meeting of the 113th session was held in the Institution Rooms, St. Andrew Square, Dr. Ramsay H. Traquair, F.R.SS. London and Edinburgh, president, in the chair.-A nest of the reed-warbler, found near Combe Abbey, Warwickshire, was exhibited to the Society by Dr. Herbert.-The opening address of the session was then delivered by Dr. Archibald Geikie, F.R.SS. London and Edinburgh, Director-General of the Geological

Survey of Great Britain and Ireland on "The Relation between Geology and Paleontology."

SYDNEY

The

Linnean Society of New South Wales, September 26.Dr. James C. Cox, F.L.S., in the chair.-The following papers were read :-On a very dolichocephalic skull of an Australian aboriginal, by Baron N. de Miklouho Maclay. The cephalic index of this skull, which was found in the interior of Queensland, was only 58.9, calculated on the ophrio-occipital length, and 58 3, calculated by the glabello-occipital length, an index lower probably than that of any skull hitherto described. skull was not a deformed one in the ordinary sense, but was a fair example of the so-called roof-shaped type of cranium.-On a fossil humerus, by Mr. C. W. De Vis.-Notices of some undescribed species of Coleoptera from the Brisbane Museum, by William Macleay, F.L.S. The species described are a few unnamed Coleoptera occurring in a large collection sent by Mr. De Vis to the author for identification. Their names are:Pamborus viridiaureus, Catascopus laticollis, Eutoma ponctipenne, Carenum terræ-regina, C. ianthinum, C. De Visii, C. pusillum, Tibarisus robustus, Pacilus lavis, Diphucephala hirtipennis, D. cærulea, D. latipennis, and Liparetrus convexiusculus.

PARIS

Academy of Sciences, November 19.-M. Blanchard, president, in the chair.-Remarks on the recent volcanic disturbances in Sunda Strait; mineralogical analysis of the ashes collected, by M. Daubrée. From the examination of these ashes, which fell at Batavia on August 27, the author considers it highly probable that the surface waters penetrating deeply into the underground cavities, and there becoming superheated, form the chief agency in such volcanic eruptions as those of Krakatoa and Ischia.-On the velocities acquired in the interior of a vessel by the various elements of a fluid during its discharge through a lower orifice (continued), by MM. de Saint-Venant and Flamant.-On the process of purple dyeing amongst the ancients according to a fragment attributed to Democritus of Abdera, by M. Berthelot.-On the production of extremely low temperatures by means of continuous apparatus, by M. Cailletet.-Report on the French expedition to Cape Horn, by M. Martial. The expedition, undertaken mainly to observe the transit of Venus, embarked on board La Romanche at Cherbourg on July 17, and reached its destination on September 6. Three contacts were observed under favourable conditions by M. Courcelle-Seneuil. part of Tierra del Fuego was visited, numerous dredgings were made at various points, and rich collections, especially botanical and ethnological, were brought back These included living

A great

specimens of most of the Fuegian flora, two native canoes with their full equipment, a com¡ lete hut with all the utensils, arms, and other objects in use amongst the aborigines. A cairn twenty feet high was erected in Orange Bay to commemorate the French expedition to Cape Horn.-On the transformations of which certain equations of the second order are susceptible, by M. R. Liouville. On the electrochemical energy of light, by M. F. Griveaux.-Observations of the Pons-Brooks comet made at the Paris Observatory (equatorial of the west tower), by M. G. Bigourdan.-Observations of the same comet and of the planet 234 made at the Marseilles Observatory, by M. Coggia. - Photometric observation of an eclipse of the first satellite of Jupiter, by M. A. Obrecht. - Remarks on a formula of Tisserand connected with celestial mechanics, by M. R. Radau. — On the resisting power of a ring, by M. J. Boussines q.-On the curve-lines of wave surfaces, by M. G. Darboux.-Application of a proposition in mechanics to a problem connected with the figure of the earth, by M. E. Brassinne.-Note on the action of carbonic acid on saccharine dissolutions more or less charged with lime, by M. D. Loiseau. -On a new kind of ureometer (one illustration), by M. W. H. Greene.-Experiments on the passage of charbon bacteridae into the milk of animals affected by charbon, by MM. J. Chambrelent and A. Moussous.-On the embryogeny of Sacculina carcini, an endoparasitic crustacean of the order of Kentrogonides, third note, by M. Yves Delage. In this highly important contribution to the study of parasitic entomology the author proposes to constitute a new order of Kentrogonides, distinct from, but allied to, that of the Cirrhipedes.-Development of the Stylorhynchus, by M. A. Schneider. On the genus Ptychogaster, Pomel, a fossil Chelonian found associated with the remains of crocodiles in the Saint-Gérand-le-Puy formations, by M. L. Vaillant.—On “vaugnerite,” a phosphatiferous rock occurring in the Irigny district on the banks of the Rhone, by M. F. Gonnard.-Note on a prehistoric flint mine worked during the Stone age at Mur-de-Barrez, Aveyron, by M. E. Cartailhac. -Concluding remarks on the waterspouts observed at Villefranche-sur-Mer, Maritime Alps, during the month of October, 1883, by M. J. Jeannel.-Note on the effects produced by lightning during a thunderstorm at Rambouillet on November 10, by M. A. Laugier.

IN

N NATURE, vol. xxii. p. 587, there appeared a notice of the anniversary address for that year to the Academy of Natural Sciences in Munich delivered by Prof. Karl A. Zittel, the well-known Professor of Geology and Palæontology at the Munich University. The address contained a preliminary sketch of the work, the complete account of which occupies the quarto volume and portion of a second volume now before us.

In the winter of 1873-74 a scientific expedition under the leadership of Gerhard Rohlfs was despatched with aid from the late Khedive of Egypt, Ismail Pacha, to explore the Libyan desert or north-eastern portion of the Sahara. The scientific results of this expedition are now being published in a series of separate volumes, of which the Geology and Palæontology will form two. The first of these lies before us, the second is as yet incomplete, and only one section containing a description of the Eocene Echinoidea, by P. de Loriol, has hitherto appeared. The first volume comprises the geological description of the country by Prof. Zittel himself, an account of the fossil wood from the Nubian sandstone and from the wellknown "fossil forest" near Cairo (Cretaceous), by Dr. A. Schenk; of the Miocene fauna of Egypt and the Libyan desert, by Dr. Th. Fuchs; of the Tertiary (Upper Eocene or Oligocene) fossils from the western island in the lake of Birket-el-Qurûn (about fifty miles south-west of Cairo), by Prof. Karl Meyer-Eymar; of the Foraminifera (the Nummulites excluded) from the Eocene beds of the Libyan desert and Egypt, by Conrad Schwager; a monograph of the Nummulites from the same areas, by the late Dr. Phil. de la Harpe; and a description of the Eocene corals, by Magister E. Pratz. These palæozoic descriptions are illustrated by thirty-six plates.

On the geological map in the first volume an area occupying rather more than 5o of latitude (25° to 30° N.) and above 8 of longitude (about 25° 30' to 33° 40′ E.) is coloured. This country includes the Nile valley from Cairo to Edfu (the geology of the valley itself is shown as far south as Assuan), and extends eastwards to the shores of the Red Sea, and westward far into the great desert tract of Northern Africa. The whole area coloured geologically may be roughly estimated at between 150,000 and 160,000 English square miles.

It will easily be understood that the mapping is of a very rough description, a geological sketch in fact, but in desert countries, owing to the want of vegetation to conceal the rocks, and to the clearness of the atmosphere, it is remarkable with what accuracy geological formations can be traced by the eye to great distances. A considerable proportion of the area is coloured from the observations of other travellers, and especially of Schweinfurth. The routes of the expedition under Rohlfs and of other travellers are marked on the map, and show how much of the area has actually been examined.

Among the numerous points of interest presented by the volume it is difficult to select any one as superior to the others. In the former notice in NATURE the general characters of the geological systems observed (Cre. taceous, Eocene, Miocene, and the so-called Quaternary and recent) were briefly described. To enter at any length into a notice of the palæontology would take too long. At the present time when the writings of F. von Richthofen and others have called especial attention to the subaërial or Eolian formations of the latest geological times and the present day, the description of the surface phenomena presented by the desert tracts of the Sahara, coming from so keen an observer as Prof. Zittel, are well worthy of attention, and a few remarks upon them may prove interesting.

The geological portion of the work is divided into two chapters: the first, containing forty-two pages, being devoted to the Sahara as a whole; the second to the geology of the Libyan desert and Egypt. In both of these chapters considerable space is devoted to the superficial characters of the desert. The surface of the Sahara is divided by Prof. Zittel, according to its characters, into four kinds :—(1) Plateau-desert or Hammâda, occupying the largest portion of the area, a level, hard, stony surface in general, without noteworthy elevations or depressions, but passing locally into (2) mountainous desert. The so-called (3) erosion-desert consists of depressions more or less occu

remarkable and interesting of all, is the (4) sandy desert or Areg, composed of drift sand forming hills or downs (dunes).

An array of scientific names like the above, chosen from amongst the most eminent specialists of Germany, Switzerland, and France, proves that this is a work of more than ordinary geological importance. The principal author and editor, Prof. Zittel, is both a good geologist and a good palæontologist, a much rarer combination than is usually supposed.

VOL. XXIX.-No. 736

Prof. Zittel shows, on what appears to be an overwhelming amount of evidence, that the popular idea of the Sahara having been the basin of a sea in Pleistocene times is without foundation. The greater part of the area has apparently been above water ever since the Cretaceous epoch; a comparatively small tract in the north-eastern portion was submerged beneath a Tertiary sea, whilst the only part that can have been under water in post-Tertiary times consists of a tract extending from the Nile delta to the oasis of Ammon, and to the so-called "Chotts" of Tunis, and even in this tract marine conditions in late

G

geological times are doubtful. But Prof. Zittel considers that the climate must have been damper, the rainfall heavier, and freshwater denudation more active in Pleistocene days than now, to account for the erosion that has taken place, the abundance of fulgurites, and the present distribution of the fauna and flora, especially in such cases as the occurrence of Central African crocodiles in the marshes and streams of the completely isolated Ahaggar Mountains. Reasons are also given for believing that the Nile was formerly a larger river than it now is. It is probable that Prof. Zittel's views on some of these points will be contested, but it is impossible to deny that his arguments are admirably expressed and clearly reasoned out.

Some very interesting details are given about the desert sand, and a careful description of its arrangement in the form of sandhills. The sand of the Sahara is considered to have been largely derived from the decomposition of the so-called Nubian sandstone, the original matrix of the well-known silicified wood. In the Libyan desert there are some remarkable anomalies in the arrangement of the sandhills, and it is clear that they cannot have been entirely formed by accumulation through the agency of the prevailing wind as it exists at the present day. It may here be remarked that very similar observations were made, a few years since, upon the sand ridges of the Indian desert east of the Indus. Some of the sand ridges, both in Africa and India, attain an elevation of about 500 feet, and in both areas the largest appear to have undergone no change within the memory of man, although in places, in both continents, moving tracts of sand occasionally overwhelm cultivated land and buildings.

One mistake in the book deserves notice. In the comparative table of Upper Cretaceous and Eocene beds in Europe, Asia, North Africa, and North America the position assigned to some of the Tertiary stages of the Indian rocks requires correction. The lower Nari beds in especial were never supposed to be so old as Middle Eocene (Parisian), and they are now known to be in all probability true Oligocene. But trifling mistakes of this kind are to be expected: it is surprising that more should not have been observed.

trusses, suspension bridges, arched ribs, and in conclusion one on ❝details of construction," which includes a discussion of the strength of rivets and other fastenings.

In his exposition of these subjects the author manifests a power of clear and precise statement; and the treatment of the more difficult problems of the first part is perhaps as profound as could be attained without a knowledge of the general theory of elasticity. The numerous illustrations serve sufficiently well in Part I., where they consist chiefly of diagrams; but in Part II. they are on too small a scale for the complicated structures illustrated: and in clearness of detail are far below the standard reached in recent English books on the same subjects. Analytical methods are preferred throughout; and generally speaking geometry is used merely to illustrate results previously obtained in a symbolical form. Thus graphical statics is quite subordinate in Part II.; stress diagrams are introduced, but there are not sufficient instructions in the text to enable a student, who has not studied the subject independently, to construct them for himself.

In the extended treatment of a parabolic rib of uniform stiffness (pp. 101-120) the author follows very closely the lines in Rankine's "Civil Engineering," with some further consideration of the additional terms depending on change of temperature.

There is no acknowledgment in regard to this and other parts of the work where Rankine's influence is clearly apparent. But as no preface is given to the present volume, perhaps other portions of the great subject of applied mechanics are in course of preparation by our author; and till the completion of his work he is postponing the statement of his obligations to those who have gone over the ground before.

We have referred to the apparent excess of symbolical reasoning: but none of this is due to the introduction of investigations better left to treatises on pure mathematics and theoretical mechanics.

Difficulties special to the subject of the work, such as the equations of the "neutral axis" (so-called) for all the different modes of loading and supporting a beam, the theorem of three moments, the moments of inertia of complicated forms of section, the deflection of struts, are however treated with the fullness of detail required by ordinary students.

Such investigations constitute the best feature of the book. The detailed application to problems such as occur in actual practice is but slightly touched on; perhaps for this we are to look to the "Examples," of which some few are worked out in the text; appended to the several chapters, moreover, are close upon 400 proposed for the

LETTERS TO THE EDITOR

[The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts. No notice is taken of anonymous communications. [The Editor urgently requests correspondents to keep their letters as short as possible. The pressure on his space is so great that it is impossible otherwise to insure the appearance even of communications containing interesting and novel facts.] Meteors

HERE, November has generally been unpropitious for astronomical observations. However, during favourable intervals I have seen many brilliant meteors; from twenty to thirty on an average every night. They were principally seen with the face to the north, and glancing from shoulder to shoulder; but not a single Andromede did I see. I had the pleasure of seeing altoge her about a score of Leonids before the 12th and after the 19th November. Leo Minorids and Arietids were plentiful, and a goodly number of Geminids were seen; but the richest field for meteors during the month was in the neighbourhood of the Plough. November 6, at 4.30 a.m., a large meteor passed from y Ursa Majoris right down to the horizon. From 4.35 to 5.15 three veritable Leonids proceeded from the Sickle; one da hed down to the right-hand, and another from the top of the Sickle to the left over the Lion's back. They were very large. November 10, at 8 p.m., a brilliant meteor started from a point nearly half way between Aldebaran and Saturn, and disappeared at a point down more than half way to the horizon. At 9.30 a very bright one appeared at a point about 1° above Castor and above Jupiter to the north. At 11.25 an exceedingly large and brilliant meteor burst out from below Menkar (in the Whale), and went down at right angles to the very horizon, leaving a long, bright streak behind. November 11, a large one, at o. 15 a.m., dropped down to the horizon from Ursa Majoris. At 0.55 a.m. a very large one proceeded from to the right of a Lacerta and disappeared at y Cygni. November 18, at 1.40 a.m., a very large reddish meteor burst out from the top of Ursa Major's head, and passed right above Vega, and disappeared about 4° beyond it in a strange sparkling explosion. At 1.55 a.m. a very brilliant meteor dashed out about 2° above a Arietis, went through the Square of Pegasus, leaving a beautiful stream of blue fire behind, and lasting a few seconds. About 5.30 another large blue meteor passed from the centre of Leo's back through a point 4° above Denebola, and ended in a beautiful explosion 15 beyond. On the night of November 22 there was a fine display of (generally) large meteors from Taurus to Ursa Major; many of them proceeded from the Lion's Head. During the month a great number of meteors passed from some point in Scorpio, under Jupiter and Mars, right into the Lion's Head. They were all large and bright. During the last half of the month some fine displays of morning meteors were seen. 4 a.m., November 29, I observed a very large and swift meteor. It blazed out from a point about 8° above Denebola, and dashed with great velocity up the heavens, passing 4° above 8 Leonis and over the Lion's Head, and exploded about 5° beyond, leaving a stream of the most beautiful blue light in its wake that I ever witnessed. DONALD CAMERON

Mossvale, Paisley, December 3

At

As your columns frequently contain notices of meteors, I may mention that I observed one of unusual brilliancy last night (November 28) at 10.50. It appeared in the constellation Taurus, and, following the line of the ecliptic, disappeared about five to ten degrees above the eastern horizon. The meteor was visible for not less than fifteen seconds, had a brilliant train or cone of light of from two to three degrees in length, and outshone Jupiter, near which it passed. From the slow, angular movement of the meteor I feel certain that the train was not an F.R.S.E. optical impression, but a real luminous object.

Edinburgh, November 29

A FINE meteor was observed here by me at Ioh. 38m. last night, Wednesday, November 28. Bursting into sight near

Ursa Majoris, it passed in a course almost parallel to, but about 2 north of, a line joining a, d, e, $, and 7 Ursa Maj., its light expiring near A Bootis. Length of path = 40°. No train was observed; the only variation of uniformity of light being at

about half way of its passage, where it slightly paled for an instant and then as quickly recovered. Duration about four seconds. Brilliancy three or four times Venus at its brightest. Colour resembled that of magnesium light. W. WICKHAM Radcliffe Observatory, Oxford, November 29

LAST night, about 10.30, I saw a magnificent bolide shoot across the sky in a northerly direction. It came from the middle star in Orion's belt, and disappeared at a point almost in a line with "the Pointers" in the Great Bear, and at a distance below the lower of the two stars almost equal to the distance between them. Its path was perceptibly arched, but not to any great extent, and, as far as I could judge, it was not parabolic. When the bolide first appeared, it seemed a mere luminous point moving with great rapidity, and without a tail. But about half way it suddenly grew large and brilliant, a tail shot out, and the path behind it remained luminous and distinct. I could compare the bolide at this point to nothing so much as to a red-hot cannon ball emitting sparks of fire. It was accompanied by no sound, and was gone in half a dozen seconds. During its passage the streets seemed to be lit up with the electric light. It was apparently so close that I should think a few miles would ́ have made a very : ensible difference in its apparent position in the heavens. J. B. OLDHAM

Stockport, November 29

north-west, near the fire, not so bright as

LAST night at 11h 2m. I saw in the horizon, one of those slow-moving balls of an ordinary meteor, and leaving no train. This seemed the size of a cricket ball; but I have seen one the size of a cheese-plate. A few flashes of lightning occurred soon after. From the slowness of the motion the phenomenon seemed to be wholly atmospheric. It was in sight for about three or four seconds. It instantly suggested an incandescent vortex whorl; but I cannot say whether the appearance confirmed the idea or not, for I do not know how such a meteor would look. Its red light might be due to its proximity to the horizon, perhaps 8°. Hence there is no dependence to be placed upon my impres ion that the light was the result of friction rather than of electricity. I have seen probably a dozen in the course of my life, always in the west or north-west, and always about the same height from the horizon, but never annular. HENRY H. HIGGINS

Rainhill, December 4

"Anatomy for Artists "

MAY I add a few more words on the subject of Mr. Marshall's book, and in answer to his letter in NATURE? Mr. Marshall says the reasons that led him to adopt the plan of omitting reference letters to his illustrations of the bones "still remain sound." Turning to p. 30 of the book to learn those reasons, I find he says that "The numerous minute points which demand the attention of the anatomist and the surgeon necessitate such aids; but the art-student's mind should be left unincumbered by such unnecessary details."

I cannot see that this is a reason; I wanted references to what is described in the text-to the necessary, not the unnecessary details.

Secondly, Mr. Marshall says, "The pure form of the bones, represented on so small a scale, in black and white, would have been seriously marred by such references." If this be "sound," may there not be more and equally sound reasons for opposing it? I think there are; and if Mr. Marshall will turn to p. 136 of the bock, I will try to show him how his plan works. The student reads there that "All the bones of the hand are visible in the skeleton, on its palmar aspect (Fig. 58), carpal, metacarpal, and phalangeal;" he turns to Fig. 58, but where is it? It is mentioned in a list of figures under three illustrations. He has to make up his mind which of the three is 58, recalls that it is the palmar aspect, and goes on. He has no clue, let Mr. Marshall observe, by which to know which are the carpal, metacarpal, and phalangeal portions of the hand for which he originally looked at the palmar aspect of it. He hopes he may come to that; and, reading on, finds that the eight carpal bones are "in the carpus ; but then, which is the carpus? He does not know, and is not told. Never mind, he thinks, he will find that out by the description of the single bones, and, beginning with the first-mentioned, he reads that the semi-lunar bone

. . occupies the centre of the first row, and is crescentic