Geological Changes of Level

IN a most friendly notice in your last issue of the Memoirs forming the first volume of the official Report of the Challenger Expedition, Prof. Huxley takes exception to a sentence in my short Introduction. "There seems to be sufficient evidence that all changes of level since the close of the Paleozoic period are in direct relation to the present coast lines," and he asks in what possible sense this can be the case. I fully admit the criticism, and that the sentence as it stands does not explain itself.

That it is not a relation of ordinary parallelism Lyell's and D'Orbigny's maps of old coast-lines, a map published by myself in "The Depths of the Sea," and particularly the beautiful later maps of Jurassic, Cretaceous, and Tertiary France by M. Delesse, abundantly show. I have explained my idea of the relation in position between the recent deposits and those of the Tertiary and Secondary periods in "The Depths of the Sea" (pp. 472-476) at some length. I believe that the Jurassic, the Cretaceous, and the Tertiary formations are essentially marginal deposits, and that their belts of deposition form approximately a series of contour bands upon an elevation which has persisted throughout a long series of local and general oscillations, the sum of which has raised the whole through a small vertical range. Such oscillations have also, doubtless, affected the bottom of the sea, but nowhere to such an extent as to modify in any important degree the conditions of the abyssal region.

Prof. Huxley says, "There is nothing, so far as I am aware, in the biological or geological evidence at present accessible, to render untenable the hypothesis that an area of the mid-Atlantic or of the Pacific sea-bed as big as Europe should have been upheaved as high as Mont Blanc and have subsided again any time since the Paleozoic epoch, if there were any grounds for entertaining it." I think however he will admit that the following Challenger data, if they can be established, afford at least a presumption against an oscillation of such a kind, at all events in post-Triassic times, beyond which it is difficult to stretch even the imagination,

The careful researches of my colleagues, Mr. Murray and the Abbé Renard, with which I have had the advantage of being familiar during their progress, have led us to the belief that (1) the chalk of the Cretaceous period was not laid down in what we now consider deep-water, and that its fauna, consisting mainly of shallow-water forms, merely touches the upper limit of the abyssal fauna; and (2) that no beds exist in the series of known sedimentary rocks which correspond in composition and in structure with the beds now in process of formation in the abyssal sea ("The Atlantic," vol. ii. p. 299).

The hypothesis of the elevation of a mass of land equal to Europe and as high as Mont Blanc in the middle of one of the great ocean basins could in our present state of knowledge be defensible only on the supposition that it was a phenomenon of the same order as the elevation of some portion of our existing continental land, and there is now, to say the least, grave reason for doubting that any rock which is due to accumulations formed at depths over 2500 fathoms, the average depth of the basins to which Prof. Huxley refers, enters into the composition of any existing continent. The present land consists of a set of crystalline rock-axes of various ages, with a long succession of sedimentary deposits, all of which give evidence of having been laid down in water of moderate depth, piled up upon and against them. Such a hypothesis therefore, besides being without a single fact in its support, would be met by a strong adverse argument from analogy, and would be, so far, in a case than the hypothesis of the origin of species by natural selection.

worse

I thoroughly agree, however, with my friend Prof. Huxley that "the value of the great work which is now being brought before the public does not lie in the speculations which may be based upon it, but in the mass and the solidity of the permanent additions which it makes to our knowledge of natural facts," and I imagine that all of us who are engaged in that work look upon it as our first and paramount duty to present these natural facts which have been acquired as simply and as effectively as we can. Still the generalisations or impressions, or whatever they may be, of the few men selected to observe these facts are as much a part of the result of the Expedition as anything else, and I think it is also our duty to offer them to our fellow-workers for what they are worth, C. WYVILLE THOMSON

Bonsyde, Linlithgow, November 6

THERE is a typographical error in my notice of the Challenger publications, published in last week's NATURE, for which I should, of course, be disposed to blame the printer, had it not been hinted to me that my handwriting is sometimes not so clear as might be wished.

I appear (p. 2) to agree with the proposition that "the deep-sea fauna presents us with many forms which are the dried and but little modified descendants of Tertiary and Mesozoic species."

As few things can be much wetter than the inhabitants of the ocean abysses, this opinion seems to be, to say the least, eccentric. But "dried" should have been printed "direct," which was the word denoted by my graphic symbols. T. H. HUXLEY 4, Marlborough Place, Abbey Road, N.W., November 7

Correspondence of Phenomena in Magnetic Storms THE Astronomer-Royal having lately received from the Observatory of Zi-ka-wei, in China (latitude 31° 12′ north, longitude, from Greenwich, 8h. 6m. east), lithographed copies of the photographic traces of the declination and horizontal force magnets, extending from August 11 to 14, and from August 17 to 20 of the present year, has placed them in my hands for comparison with the Greenwich records. Some particulars of this comparison are herewith annexed. Greenwich time is used throughout.

A general examination of the two sets of curves shows that the disturbances were usually greater in magnitude at Greenwich than at Zi-ka-wei. Comparing the curves in detail, it is found that on August 11, at 10.201 a.m., after a quiet period, the declination and horizontal force magnets at Greenwich both made a sudden start, which was the commencement of a magnetic disturbance, lasting until midnight. An apparently equally sudden start (from a quiescent state), in both declination and horizontal force, is shown on the Zi-ka-wei curves, occurring in declination at 10.12 a.m., and in horizontal force at 10.20 a.m. (as nearly as the small scale on which the curves are drawn will the west declination and increase the horizontal force at both allow measures to be made). This first motion was to decrease places. A bold motion in the two Zi-ka-wei curves at 11.30 a.m. (increase of declination, decrease of horizontal force) has corresponding decrease of horizontal force at Greenwich, not accompanied, however, by much motion in declination. And of numerous fluctuations occurring at Greenwich between noon and midnight of the same day, some appear to correspond with

motions at Zi-ka-wei, whilst others do not.

12.

A calm state follows at both places, until near noon of August On this day at about 11.40 a.m. the magnets at Greenwich made a further start, and until 4 p.m. the movements were large. A corresponding start is also shown in both the Zi-ka-wei curves (commencing, according to the register, some minutes sooner than at Greenwich), the movements following being similarly large. Afterwards, until 6 a.m. of August 13, considerable oscillation was nearly continually shown at Greenwich, there being especially a large change of declination between 7 and 9 latter time at Zi-ka-wei, and the changes are throughout much p.m. (August 12); but there is no strongly-marked motion at the Later on August 13 further oscillations occur at both places, but the separate motions are in no particular accordance. The period of disturbance seems definitely to come to an end at both places at 6 a.m. on August 14.

smaller than at Greenwich.

A bold increase of

A period of quiet is broken at Greenwich on August 18, at 1.45 p.m., by a sharp though small movement both in declination and horizontal force (increase of both). There is a corresponding sharp increase (after quietude) of horizontal force at declination and decrease of horizontal force at Greenwich at 7 Zi-ka-wei, but no change of declination. a.m. of August 19 is accompanied by a similar decrease of horizontal force at Zi-ka-wei, but with little change of declination. paratively small change at Greenwich. The magnets become Bolder changes occur at the latter place at noon, but with comquiet at both places at or near midnight of August 19. ka wei curves appears to be that, after a quiet period, the first The general result of this comparison of Greenwich and Ziindication of disturbance, if sudden (it need not be large) occurs simultaneously or nearly so at both places, but that during the

Approximately stated to be 10.30 in my previous letter (NATURE, vol. xxii. p. 361), and so quoted by Mr. Whipple (p. 558) The time above given is more exact.

continuance of disturbance the oscillations of the magnet eem to be so locally modified that it becomes difficult to trace corre. spondence: some movements appear to correspond, and some not. A strongly-marked bend in the trace at one place may appear, as it were, stunted in that at the other place, or may not be perceptible at all. The disturbances appear to die out at pretty much the same time at both places. All this confirms very much what Mr. Whipple has already pointed out as regards Melbourne (NATURE, vol. xxii. p. 558).

M. Dechevrens, in some remarks which accompany the sheet of curves, notes that the disturbance of August 11-14 is the greatest experienced since the establishment of photographic registration at Zi-ka-wei in the year 1877, and he considers that the changes then observed (those of vertical force included, of which he gives no curves) are similar to such as would be produced by a powerful magnet placed in a certain defined position. It may perhaps be here pointed out that the results given by the Astronomer-Royal in his paper, "First Analysis of One Hundred and Seventy-seven Magnetic Storms" (Phil. Trans. for 1863) appear to give no support to a theory of this kind, and indeed seem conclusively to show that at Greenwich the observed disturbances cannot be accounted for in any such way.

It should be added that M. Dechevrens reports also that strong earth currents were experienced on August 11 and 12 on the submarine telegraph lines connecting Shanghai with Nagasaki and with Hong-Kong, as well as on the land lines in Japan, so much so that correspondence was frequently interrupted, but that no interruption appears to have been experienced on the occasion of the generally smaller magnetic disturbance of August 18. WILLIAM ELLIS

Royal Observatory, Greenwich, November 6

Meteor

A VERY large and brilliant meteor was observed here at 6h. 41m. p.m. G.M.T., on November 8. Its size was at least equal to one-fourth of that of the full moon, and it lit up the whole garden for about a second and a half. It was pear-shaped. The colour was white, and left behind it a pale red train. Its path was from a point half-way between a and & Persei to 3° above Ursa Majoris. The sky was rather bazy at the time. Stonyhurst Observatory, November 9

Condition of Jupiter

S. J. PERRY

On the evening of the 2nd I had a fine view of Jupiter with my 6-inch Cook's equatorial. The general appearance of the planet was remarkable for the bright colouring of the belts and of the red spot, a circumstance strongly noted by a gentleman who was observing with me, and who had not seen the planet for some time.

I could not however trace the usual white ring round the red spot. Below the red equatorial belt was a row of four or five small irregularly-shaped spots, nearly black in tint, and resembling sun-spots seen under a low power.

These dark spots seem now affecting Jupiter's surface in several parts, and are certainly not usual to it. About 9h. 26m. Satellite I. was occulted. I watched it gradually coming to contact, and at last it seemed to advance on the face of the planet, at least one-half of its diameter appearing to project thereon. It then faded out gradually.

September 3, 1879, at 9b. Sm., with the same instrument Satellite III. reappearing after occultation, was slightly (but certainly) projected on to the disk of the planet. It will be interesting to notice whether the present condition of Jupiter will be accompanied by more than ordinary displays of aurora, of which symptoms have already appeared.

Guildown, November 6

J. RAND CAPRON

P.S. Since writing the above accounts reach me of aurora at Brighton on the 3rd and in the Orkneys on the 4th instant.

Vox Angelica

MANY of your readers may be acquainted with the nature of the Vox Angelica stop on a good organ. It consists of two ranks of pipes of small scale and delicate quality of tone, one of which is tuned slightly sharp, so that a wavy (hence called Unda Maris) sound is produced. Now it is possible to obtain very similar effects on an ordinary Estey American organ. Given the viola and violetta stops to be drawn out, wrap a band of india-rubber

Any

(an ordinary clastic band does very well) round the neck of the viola stop so that it cannot return completely home, on moderate pressure, and allowing a fraction of an inch to intervene between its true final position when inactive; beats will be heard of intensity depending upon the deviation from complete occlusion of this stop. The nearer the viola stop is to occlusion the more rapid the beats; but it is undesirable to obtain rapidity, as the lower notes are too prominently out of tune in this case. body can, by experiment, determine the proper amount of deviation to be employed, and having done this the effect is remarkably good. On an Estey, the two stops mentioned are the only admissible ones for such an experiment, from consideration of overtones. No doubt some of your readers may adopt a more elaborate and convenient method of regulating the deviation than by elastic bands, after some experiments. It may seem a paradox to obtain beautiful concordant effects by the use of discordant vibrational relations, but it is undeniable that on a first-class organ the Voix Celeste, or Vox Angelica, or Unda Maris, is a most beautiful stop, and is capable of producing perfect con sordini effects. GEORGE RAYLEIGH VICARS

Woodville House, Rugby, November 3

Solids and Liquids at High Temperatures

SOME years ago I made an investigation much simpler but somewhat similar to that referred to by Prof. Carnelley in NATURE, vol. xxii. p. 435. An account of the experiments then made was communicated to the Royal Scottish Society of Arts, 1874-75. One of the results of that investigation was that while we do know something about the temperatures at which different forms of matter change from one state to another when a "free surface" is present, yet we are utterly ignorant of the temperature at which that change will take place when no "free surface" is present. It will be necessary here to explain that a "free surface" is any surface of the body under examination at which it is free to change its state. A surface of water, for instance, in contact with its own vapour is a "free surface" for the water passing into the gaseous state. The surface of a piece of ice in water, again, is a "free surface" at which the water may freeze or the ice may melt. And what are known as the freezing, melting, and boiling points of water are the temperatures at which these changes take place when such "free surfaces" are present. As to what the freezing, melting, and boiling points are when these "free surfaces" are absent, we have at present no knowledge whatever. All we know is that the freezing point is lower, and the "melting" and "boiling points" are higher, than when "free surfaces" are present.

The first of these points is too well known to be referred to here. The last point was illustrated in the paper referred to by an experiment in which water was heated in a metal vessel under atmospheric pressure to a temperature far above the "boiling point, when the water exploded and violently ejected itself from the vessel. The superheating of the water was accomplished by carefully excluding all "free surfaces" by bringing the water into as perfect contact with the metal of the vessel as possible.

Many experiments were also made to get direct and thermometric experimental illustration of the existence of ice at a temperature above the "melting point," but no satisfactory illustrations were got, on account of the great difficulty of getting quit of "free surfaces." Of course so long as there existed a "free surface" at the surface of contact of the ice with the thermometer, the temperature at that part could not rise above the "melting point." It was however shown by indirect evidence that ice may exist at a temperature above the "freezing point" by referring to the well-known and beautiful experiment of passing a beam of light through a block of ice. When this is done with the aid of proper apparatus it is seen that the heat of the ray is absorbed by the ice, and that melting takes place at different points inside the block. Now the presumption is that the heat is absorbed at all points inside the block, but as the melting only takes place at certain points the heat absorbed where there is no melting must raise the temperature of the ice at those points above the "melting point," and the heat there absorbed by the ice will be conducted to the "free surfaces," where it is spent in melting the ice.

Now though I was perfectly prepared to find that Prof. Carnelley had succeeded in heating the inside of a block of ice to a temperature above the "melting-point,' I certainly did not expect so high a temperature as his experiments indicate to be

possible. But what is still more puzzling is how Prof. Carnelley succeeded in burning his fingers with the ice. Our previous knowledge would lead us to suppose that the outside surface of the block of ice was a free surface, and that therefore it would be impossible, however high the temperature of the inside of the block, to heat the outside above the "melting point," as we should expect the ice to melt or to sublime at the outside, and keep the temperature at o° C.

These expectations being disappointed, we naturally look to the decreased pressure under which Prof. Carnelley's experiments were made for an explanation of this most unexpected state of matters. Now it is very evident that when dealing with pressures of about one atmosphere, and with temperatures of 120° and 180° C., that pressure, as pressure, has nothing whatever directly to do with the "melting point" of the ice. While this is the case, it is equally evident that it has a most important influence on the surroundings of the ice. At the pressure of 4'6 mm., at which the experiments were made, no water would be present, there would be nothing but ice and water-vapour. Here then appears to be the great teaching of Prof. Carnelley's experiments. They show that the surface of ice bounded by its own vapour is not "free surface." This result is so very unexpected that much consideration will be necessary before we can re-arrange our ideas to meet the new facts.

a

We might imagine that nothing could be more free than the surface of a body bounded by nothing but its own vapour, yet Prof. Carnelley's experiments seem to say it really is not so, and not being a "free surface," we of course know nothing whatever of how high the temperature will require to be before the ice will melt under these conditions.

These experiments of Prof. Carnelley's are so interesting that we wait with impatience a full description of them. His results indicate something new with regard to the influence of a liquid on its melting solid. I observe that Prof. Carnelley's results are doubted by most of your correspondents, but for the present we must accept them when Prof. Carnelley distinctly states that the temperature of the ice was taken by means of a thermometer in contact with the ice. JOHN AITKEN

Darroch, Falkirk, N.B., October 30

Wire Torsion

IN the letter in NATURE, vol. xxii. p. 604, which we wrote at the request of Major Herschel, who asked for information regarding the connection between tensional and torsional strains of a brass wire, we mentioned that there were many papers scattered through the Proceedings of learned societies dealing with the fluidity of metals. There is one communication to which we might specially have referred, as it deals in particular with the torsional yielding of wires under tension, and this is a paper on "Torsion," by Prof. G. Wiedemann, in the Annalen der Physik und Chemie, No. 4, vol. vi., 1879, pp. 485-520, and of which a translation is given in the Philosophical Magazine, vol. ix., January 1880, pp. 1-15, and February, pp. 97-109. The first part of this paper gives a detailed account of experiments which show :-(1) That a brass wire often subjected to a particular torsion, either in one or in both directions, becomes killed" for any less torsions, that is, follows Hooke's law for its temporary torsions; (2) that a wire under tension acquires greater torsional set from a given torsional couple than when the wire is unextended; (3) that a wire under even considerable tension may be killed by torsion in alternately opposite directions, that is, it will obey Hooke's law for any tension or torsion less than the stresses actually applied originally. Prof. Wiedemann in the second part of his paper considers the wellknown "agitation effects," and enters on an explanation of the phenomenon based upon molecular allineations referring to the magnetisation theory of Weber and Kolrausch which is based on the same idea.

The strains in Prof. Wiedemann's wires were however much ess than in those used in Major Herschel's experiments. JOHN PERRY

London, November 8

W. E. AYRTON

compound itself." After that it is shown that this is not the true heat of formation of the compound, as many important corrections have to be made. On referring to Berthelot's "Essai de Mécanique Chimique" I find the following:-"The heat of formation of an organic compound from its elements is the difference between the sum of the heats of total combustion of its elements and the heat of combustion of the compound with formation of identical products."

Can any of your readers inform me whether Thomsen or Berthelot first enunciated this law?

Another point is, that Berthelot apparently makes no reference to the corrections for the heat absorbed in dissociating the molecules of the elements, &c. A. P. LAURIE

Edinburgh, November I

The Yang-tse, the Yellow River, and the Pei-ho IN replying to the letter of your correspondent (NATURE, vol. xxii. p. 559) on the subject of my recent paper on these three rivers, I have to thank him for his very probable explanation of the excessive estimate made by Sir George Staunton of the amount of sediment discharged by the Yellow River.

The estimate given in my paper of the water-discharge of the River Plate is ipso facto an assumption made by Mr. George Higgin from Mr. Bateman's calculation of the minimum flow of that river, which he found to be 670,000 cubic feet per second. It might have been better, however, if I had added Mr. Higgin's qualifying remark that such an estimate of the mean volume of water was very much under the mark" (NATURE, vol. xix. P. 555).

The anomaly of the surface current varying in velocity with the same average depth of water has not been unnoticed by myself, though I am unable to give a satisfactory explanation of the difficulty. H. B. GUPPY Woodlane, Falmouth, November 6

The Thresher

WHAT is the "thresher"? It is generally assumed to be the fox-shark (Alopias vulpes), but in a recent number of Land and Water-which I have only just seen-Mr. Frank Buckland says that he believes it to be "the gladiator dolphin or sword grampus" (Orca gladiator). This he infers from a drawing of Lord A. Campbell's, of which he gives a copy. The tail, he says, is not that of the fox-shark. But as it is heterocercal it cannot be that of a grampus or any other Cetacean. Whatever it is I suppose that there is no doubt that it throws itself out of the water ("high as the masthead" [of a trawler] one of Mr. Buckland's correspondents avers). Does it do so more than once? Once, many years ago, between Sydney and New Zealand, I saw, what they said was a fight between a thresher and a whale, but there was nothing to be seen beyond a splashing of the water. Last year off Lisbon I witnessed a similar event. Does the sword-fish also attack the whale? Lord A. Campbell, in the letter accompanying his drawing, estimated the length of his thresher at upwards of thirty feet;" this is twice the length given by Yarrell.

October 30

FRANCIS P. PASCOE

Since the above was written I see that Dr. Günther, in his new work on Fishes, says: "Statements that it (the fox-shark) has been seen to attack whales and other large cetaceans rest upon erroneous observations" (p. 322).

"STUDENT" should refer to Newcomb's "Popular Astronomy" with respect to the larger telescopes. For results he must refer to the publications of the Royal and Astronomical Societies, the Washington Observatory, &c.

PAUL LAFARGUE.-We regret we have no further details on the labours of the U.S. Fish Commission in increasing the food supply of the country.

ILLUSTRATIONS OF NEW OR RARE ANIMALS IN THE ZOOLOGICAL SOCIETY'S LIVING COLLECTION

I.

THE sagacious founders of the Zoological Society of London made it a special rule that no dividends or gifts of any kind should be distributed amongst the

members. On the contrary, every Fellow has to contribute an annual sum towards the maintenance of the Society's establishment, unless he prefers to pay a life-composition in lieu thereof. Moreover, the Society are so fortunate

of liors, tigers, elephants, and other well-known animals must always be kept up for the delectation of the ordinary public, and for the maintenance of the best possible living series of animals, it is also thus in their power to acquire animals of specially scientific value, in which the casual observer would take little interest, and which would, therefore, be quite ineligible except in a scientific point of view. This course of action has been adopted for many years, more especially since the foundation of the office of "Prosector"> to the Society. For these special acquisitions not only delight the eyes of the intellectual observer while they live, but furnish the prosector with subjects for his studies when dead. Those who are acquainted with the Proceedings and Transactions of the Zoological Society of London will be well aware of the amount of work that has thus. been accomplished as regards the anatomy of many of the rarer birds and mammals.

FIG. 2.-The Japanese Wolf (Canis hodophylax). rom their income a sum sufficient to meet the annual | expenditure, they are able to devote the surplus to new buildings in the Gardens, and to the acquisition of new and rare subjects for, the menagerie. While the supply

1.

It is, however, by no means by purchase only that rare animals are added to the Zoological Society's collection. Numerous friends and correspondents in almost every corner of the earth are in constant communication with the Secretary, of the Society, and are ever endeavouring to obtain specimens that may be acceptable to the collection. In fact the donations have of late years become so numerous that they have not unfrequently rivalled in number and interest the objects acquired by purchase. Taking the acquisitions from these two sources together, there are always a considerable number of objects in the Society's collection that specially invite the attention of the observant naturalist. Amongst these rarities there are at the present moment the following, of which illustrations are given, drawn upon wood by Mr.. J. Smit, an artist constantly employed by the Zoological Society.

The musk-deer (Moschus moschiferus) was well known to the older writers on zoology as the animal that has from long periods of time supplied the "musk" of

commerce. This scent is still much in vogue in the East, but in Western Europe has been long superseded by more refined perfumes, though it may be remarked that one of the fashionable dealers in Bond Street still keeps a stuffed musk-deer in his window, and is doubtless ready to supply the product in question.

The musk-deer was until recently usually associated with another group of mammals to which it has really very little affinity. Dr. Gray and other systematists united it with the Chevrotains (Tragulus) of India and tropical Africa

a group of ruminants remarkable for their small size and hornless heads, and presenting somewhat of the appearance of diminutive antelopes. M. Alphonse Milne-Edwards of Paris was, we believe, the first naturalist to show that this allocation was unnatural. In his excellent essay on the Chevrotains, published in 1864, M. Milne-Edwards proved conclusively that these little-understood animals constitute a peculiar family of ungulates quite distinct from either the Bovidæ or Cervidæ, and in fact in some respects approaching more nearly to the pigs (Suida). The correctness of these observations has been since fully demonstrated by Prof. Flower, Mr. Garrod, and other systematists.

The musk-deer therefore remains unique in its own group, and constitutes a special division of the Cervida