types of screw surfaces can be constructed. He also gives detailed explanations of the work requiring to be done in the drawing office of an engine factory in connection with the design of screw propellers. While securing sufficient accuracy for all practical purposes, he shows how approximate methods may be substituted in many cases for exact geometrical methods. The little book may well be placed in the hands of all engineering draughtsmen and apprentices whose. training includes attendance at technical schools, as well as workshop practice.

Geographical Gleanings. By Rev. F. R. Burrows. Pp. 75. (London: G. Philip and Son, Ltd., 1906.) Price Is. 6d, net.

Mucu yet remains to be done before geography is taught and studied in schools according to reasonable methods. Everybody agrees that geography, like most other subjects, can be made a valuable educational instrument provided that it is taught by practical methods and that the teachers are familiar with its realities. Mr. Burrows describes some methods of teaching geography, and shows how the subject may be usefully approached. There is little new in his views or advice; nevertheless, the book may serve to place aspiring teachers in a position to give satisfactory lessons in geography.

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 intended for this or any other part of NATURE. No notice is taken of anonymous communications.] Chinese Observation of Nature.

I AM venturing to send you two quotations from L'Empire Chinois," by M. Huc.

(I) Refers to an instance of mutation, and seems to me to be markedly interesting on account of the date of the observation recorded, and the use made of the discovery. (II) Refers to a different matter-Polype vinaigre. Possibly this creature is well known to scientific workers, but I have failed to identify it, although I have searched all reference books at hand. Unfortunately, we have no scientific reference library, and I venture to hope that a reader of NATURE will tell us what it is!

W. HOSKYNS-ABRAHALL. 14 Woodstock Road, Redland Green, Bristol.

I.

Les Chinois doivent principalement à leur caractère éminemment observateur leurs nombreuses découvertes en agriculture, et le parti qu'ils savent tirer d'une foule de plantes négligées en Europe. Ils aiment à examiner et à étudier la nature. Les grands, les empereurs même, ne dédaignent pas d'être attentifs aux plus petites choses, et ils recueillent avec soin tout ce qui peut avoir quelque utilité pour le public. Le célèbre empereur Khang a ainsi rendu plus d'un service important à son pays. On trouve dans de curieux mémoires écrits par ce prince, le passage suivant :

Je me promenais, dit l'Empereur Khang-hi, le premier jour de la sixième lune, dans des champs où l'on avait semé du riz qui ne devait donner sa moisson jusqu'à la neuvième. Je remarquai, par hasard, un pied de riz qui était déjà monté en épi. Il s'élevait au-dessus de tous les autres et était assez mûr pour être cueilli; je me le fis apporter. Le grain en était très-beau et bien nourri; cela me donna la pensée de le garder pour un essai, et voir si, l'année suivante, il conserverait ainsi sa précocité; il la conserva en effet. Tous les pieds qui en étaient provenus montèrent en épis avant le temps ordinaire, et donnèrent leur moisson à la sixième lune. Chaque année a multiplié la récolte de la précédente, et, depuis trente ans, c'est le riz qu'on sert sur ma table. Le grain en est allongé et la couleur un peu rougeâtre; mais il est d'un parfum fort

doux et d'une saveur très-agréable. On le nomme Yu-mi, riz impérial,' parce-que c'est dans mes jardins qu'il a commencé à être cultivé. C'est le seul qui puisse mûrir au nord de la grande muraille, où les froids finissent trèstard et commencent de fort bonne heure; mais, dans les

provinces du midi, où le climat est plus doux et la terre plus fertile, on peut aisément en avoir deux moissons par an, et c'est une bien douce consolation pour moi que d'avoir procuré cet avantage à mes peuples.'

L'Empereur Khang-hi a rendu, en effet, un service immense aux populations de la Mantchourie, en propageant la culture de cette nouvelle espèce de riz, qui vient à merveille dans des pays secs, sans avoir besoin d'irrigations perpétuelles comme le riz ordinaire.

64

Huc, L'Empire Chinois," vol. ii., p. 359, second édition, 1854.

Kang-hi--1661-1721-" was indefatigable in administering the affairs of the empire, and at the same time he devoted much of his time to literary and scientific studies under the guidance of the Jesuits. Article "China,' Encyclopædia Britannica," ninth

edition.

II.

Polype vinaigre.

Le tsou-no-dze est un être qui, à raison de sa bizarre propriété de fabriquer d'excellent vinaigre, mérite une mention particulière. Ce polype est un monstreux assemblage de membranes charnues et gluantes, de tubes et d'une foule d'appendices informes qui lui donnent un aspect hideux et repoussant; on dirait une masse inerte et morte. Cependant, quand on la touche, elle se contracte он se dilate, et se donne des formes diverses. C'est un animal vivant, dont la structure et l'existence ne sont pas plus connues que celles des autres polypes. Le tsou-no-dze a été découvert dans la mer Jaune, et les Chinois le pêchent sur les côtes du Leao-tong; mais on n'en prend qu'un petit nombre. Peut-être sont-ils plus abondants ailleurs, où l'on néglige de les prendre faute de connaître leur propriété. On place ce polype dans un grand vase rempli d'eau douce à laquelle on ajoute quelques verres d'eau-de-vie. Après vingt ou trente jours, ce liquide se trouve transformé en excellent vinaigre, sans qu'il soit besoin de lui faire subir aucune manipulation, ni d'y ajouter le moindre ingrédient. Ce vinaigre est clair comme de l'eau de roche, d'une grande force et d'un goût trèsagréable. Cette première transformation une fois terminée, la source est intarissable; car, à mesure qu'on en tire pour la consommation, on n'a qu'à ajouter une égale quantité d'eau pure, sans addition d'eau de vie. Le tsouno-dze, comme les autres polypes, se multiplie facilement par bourgeons, c'est-à-dire qu'il suffit d'en détacher un membre, un appendice, qui végète, en quelque sorte, grossit en peu de temps et jouit également de la propriété de changer l'eau en vinaigre. Ces détails ne sont pas uniquement basés sur les renseignements que nous avons pu recueillir dans nos voyages. Nous avons possédé nousmêmes un de ces polypes; nous l'avons gardé pendant un an, faisant usage journellement du délicieux vinaigre qu'il nous distillait. Lors de notre départ pour le Thibet, nous le laissâmes en héritage aux chrétiens de notre mission de la vallée des Eaux-Noires.

"L'Empire Chinois, Huc, vol. ii., chap. x., pp.

414-415.

A Large Meteor.

ON Sunday, August 5, at 10h. 33m., I saw what I presume to have been a fine and rather early Perseid. It crossed the star λ Aquila, and the flight was recorded from about 2871° -2° to 282° -9°. The meteor was much brighter than Venus, and left a streak of 5° visible for some twenty seconds, though the full moon was shining brilliantly at the time.

I would be much interested in hearing of any other observations of this meteor. It was probably situated over the English Channel, and must have presented a magnificent appearance as seen from the counties of Somerset, Dorset, and Devon. W. F. DENNING.

44 Egerton Road, Bishopston, Bristol, August 6.

ATMOSPHERIC PRESSURE CHANGES OF LONG DURATION.

IN previous numbers of this Journal (vol. Ixvii.,

p. 224, and vol. lxx., p. 177) I described a barometric variation of short duration and worldwide in extent which behaved in a see-saw manner in an easterly and westerly direction between antipodal parts of the earth. The investigation, which included the examination of pressure changes at ninety-five stations scattered over the globe, indicated that there was a transference of air from west to east and from east to west alternately, a surge, in fact, raising and lowering the mean annual pressure values. Thus, when the pressure in any year in India

SUNSPOT CURVE

INVERTED

the East Indies, and Australia behaved alike, while the South American region behaved in an inverse manner. The present inquiry was therefore limited to these areas. For the first three a considerable amount of data is available, but this is not the case for the last-mentioned region; to mitigate this deficiency, curves for several separate stations have had to be employed in order to determine over several years the variation in operation there.

The first step taken to prepare the data for this comparison was to eliminate so far as possible the variation of short duration. This was satisfactorily accomplished by grouping the years in sets of four, and employing the mean values of each of these groups; thus the means for the years 1873 to 1876, 1880 0

18700

5

0

500

5

1890 0

5

19000

or Australia was in excess, that recorded in South America showed a deficiency.

During this inquiry it was noticed that there were changes going on which extended over a longer period of time than the short one (about 3.8 years) to which reference above has been made. In order to find out whether these long variations were similar all over the earth, or whether they also were of an opposite nature in different areas, several sets of long series of pressure observations have been carefully examined. The result of this limited survey recently formed the subject of a communication by the writer to the Royal Society,' and the following is a brief account of the results arrived at in the paper.

In the case of the variation of short duration, India,

1 "Barometric Variations of Long Duration over Large Areas." By Dr. William J. S. Lockyer. Read June 21, 1906.

1874 to 1877, &c., were determined. The curves here shown are all composed of such means, and are formed by connecting the points plotted on squared paper; the same scales are employed throughout.

Fig. 1 illustrates the series of curves, all drawn on the same scale, for the Indian, East Indies, and Australian areas. Bombay and Madras represent the pressure changes of the first, Batavia the second. and Adelaide, Melbourne, Sydney, and Perth are types for Australia.

An examination of these curves leads one to the following conclusions:

First, the Indian curves are very alike, and suggest a variation of an oscillatory nature, the maxima or minima occurring about every ten or eleven years. Second, the amplitude of these curves, that is, the difference between the maximum and minimum

values, has decreased considerably of recent years, and has nearly obliterated the eleven-year variation. Going further afield, the curve for Batavia (East Indies) is very similar to that of Bombay. Coming

SUNSPOT CURVE 1500

CORDOBA

COYA

SAN JUAN

SANTIACO

CURITYBA 27-04

SAMERICA 000

18600

as before, and curves drawn for five stations. Three series of observations represent the Argentine Republic stations Cordoba, Goya, and San Juan, while Santiago (Chili) and Curityba (Brazil) are also used, as they are stations situated more westerly and easterly respectively. Curves representing barometric changes at these places are all given in Fig. 2, and are drawn on the same scale. Although they extend over different periods of time, there is sufficient overlapping in all cases to allow one to draw conclusions as to the general kind of variation over this area.

to the Australian continent, it will be noticed that the eleven-year variation is well indicated in the Adelaide curve, but the amplitudes are much greater. Particular attention is directed to the maximum about the years 18761878, because in the curves for Melbourne, Sydney, and Perth this becomes quite insignificant. fact, it is the dropping out of

In

this maximum which gives the STAMERICA Australian curves quite a different appearance from those of India, although in many other respects they closely resemble the indian changes.

The Australian curves thus indicate two principal maxima about the epochs 1868 and 1887, with an intermediate subsidiary maximum about 1878; the principal maxima are thus nineteen years apart. The curve given at the bottom of Fig. 1 is drawn to represent in a general

AUSTRALIA

INCHES

002

<-001

0-00

-001

-002

003

+002

+001

0.00

-001

-002

-0-03

002

- 001

0.00

manner this variation, and to serve SAMERICA as a comparison to the other curves which follow.

An examination of the South American pressures was next undertaken. Here, as I have said before, the data are not too numerous, but I think they are sufficient to demonstrate a long variation that is in operation and the epochs of the minima.

As was done in the case of Fig. 1, a curve is here drawn at the foot of the South American curves to show the general nature of the variation in this region. Two principal maxima are very obvious about the years 1874 and 1893, while there seems to be an indication of a subsidiary maximum the mean of which is about the year 1883. We are here in the presence of a barometric change of long duration the principal maxima of which are also about nineteen years apart, so far as these observations inform us.

The question now arises, How does this South American variation compare with those shown to exist in India and Australia? This can be easily answered by comparing the curves brought together in Fig. 3.

The first point of importance is that the South American and Australian curves have principal maxima about nineteen years apart, while situated between them is another maximum of a sub

maxima and

The same method of four-year means was employed

sidiary nature. The second is that the epochs of these maxima in these two widely separated areas are not coincident. Further, we are not here in the

presence of a barometric see-saw, or opposite pressure variation, because the Australian maxima do not occur simultaneously with the South American minima; there seems to be a general time-difference of phase amounting to about six years, the epochs of the Australian maxima preceding those of the South American region. If a see-saw did exist, then the inverted South American curve should represent the Australian variation. That this is not so will be seen by comparing the two lower curves in Fig. 3.

It will thus be seen that the South American pressure type is closely similar to that existent in Australia, but unlike that in operation in India.

The magnitudes of these changes of pressure from year to year are by no means insignificant. The following table shows in compact form approximate measures of the amplitudes of the curves in the cases of both the short and long variations. The third and fifth columns of figures represent, in percentages of the annual variations, the amplitudes given in the second and fourth columns of figures:

The brief summary at the foot of the table indicates an approximate mean value of the percentages for each region. In the case of Australia, for example, the fact is made apparent that the amplitude of the variation of short duration amounts to as much as 35 per cent. of that of the mean annual variation, while the variation extending over nineteen years reaches nearly 25 per cent. Such large pressure changes must therefore play an important part in producing variations in the seasonal weather from year to year.

With regard to the origin of these long barometric changes, it is interesting to note that the Indian pressure curves resemble in general the inverted curve representing solar activity as deduced from the area of sun-spots. This fact has for many years been known, and was pointed out by Brown, Hill, Eliot, Blanford, Douglas Archibald, and others. It will be seen from the curves, however, that the

re

semblance was far more striking before the year 1880 than after it.

Since the Australian curves are allied to but somewhat modified forms of the Indian variation, it seems possible that this modification may be due to some terrestrial cause.

Mr. H. C. Russell, who is a strong advocate of a nineteen-year cycle of weather in Australia, has been led to discard solar action and to consider the moon as being the prime mover or origin of this cycle, a suggestion which he put forward in 1870, and again in 1896.

The present discussion of the barometric pressures seems to indicate that the family likenesses between the Australian and Indian curves, here shown in Fig. 1, and between the Indian curves and the inverted sun-spot curve, are sufficient to suggest for the Australian nineteen-year variation a solar origin with a terrestrial modification without having to appeal to lunar action.

WILLIAM J. S. LOCKYER.

SIR WALTER LAWRY BULLER, K.C.M.G., F.R.S.

SIR

IR WALTER LAWRY BULLER, who died on July 19 at Pontdail Lodge, Hampshire, will be remembered long in the scientific world on account of his accurate and sumptuous works on the ornithology of New Zealand. He was a son of the Rev. James Buller, of Canterbury, in the Southern Island, and was born in 1838. He was proud of being a New Zealander, and passionately devoted to all that concerned Maoriland. At the age of twenty-four, and for ten years subsequently, he filled the post of Resident Magistrate and Native Commissioner and Judge of the Native Land Court of New Zealand. Few had so intimate a knowledge of the Maoris as he possessed. In 1865, during a critical period of the Maori War, when Sir George Grey, the Governor, determined to take a personal hand in the contest in his endeavour "to quicken the slow dragging on of the military operations,' "Sir Walter served as a volunteer on his staff, and had the honour of being mentioned in despatches.

From an early age Sir Walter was a close observer of the birds of his native country. Fired no doubt by the example of (among others) Mr. Potts, an enthusiastic student and recorder of the habits of the birds of Canterbury, he, it would seem, very early conceived the ambition of making himself the authority on the birds of New Zealand. He was only thirty-four years old when, during the years 1872-3, the publication of his "History of the Birds of New Zealand, a quarto volume illustrated by coloured plates by Keulemans, placed him at once in the undisputed position of ornithologist par excellence of the colony. In bringing this splendid work to its successful birth he was greatly aided by the wide experience of his friend Dr. Bowdler Sharpe. The persistent exploration of the recesses of the country and his own continued study of its avifauna soon showed him that he had made but a contribution to the history he had undertaken. After fifteen years he brought out a second edition, in two costly folio volumes, also profusely illustrated by Keulemans, which attained a success which few bird books have ever met with. For seventeen years more Sir Walter continued gathering in the aftermath of his already great harvest, the results of which he had determined to issue as a supplement in two volumes, which, superbly illustrated like their predecessors, were only quite recently distributed.

Early in the year Sir Walter Buller was taken seriously ill, and only a few months ago the writer was permitted, during what was hoped by the sufferer himself and his friends was a true convalescence, to see him, alas! for the last time. He was dictating from his couch the concluding pages of the final volume of his supplement "to get them off his mind." Unfortunately, a relapse supervening he was removed into the country to the home of Mrs. Madocks, the daughter to whom the supplement is "affectionately dedicated," "his constant companion during its preparation, and the contributor of some beautiful photographs of New Zealand scenery to its pages." It was hoped that the change would restore the patient sufficiently to enable him to take a long, curative sea voyage. These hopes have been disappointed, and this distinguished ornithologist's life closed at the comparatively early age of sixty-eight years, with the last page of the work on which he laboured so enthusiastically for half a century.

Sir Walter Buller published many natural history papers, especially in the Transactions of the New Zealand Institute, on other subjects besides his favourite birds. He was elected to the Fellowship of the Royal Society in 1879, and the honorary degree of D.Sc. was conferred by Cambridge in 1903 in recognition of his scientific work.

Besides being a busy City man, Sir Walter held many public offices. He acted as Commissioner for New Zealand at the Colonial and Indian Exhibition of 1866, on the executive council of the Paris Exhibition in 1889, and for five years on the governing body of the Imperial Institute. He was created K.C.M.G. in 1886. A large donor to many museums at home and abroad, he received decorations from many foreign States in recognition of his generosity.

F.

THE YORK MEETING OF THE BRITISH ASSOCIATION.

THE HE seventy-sixth meeting of the British Association may be described as a very successful one. The Association was founded in York in 1831. It visited York again in 1846, and also in 1880. On the present occasion the citizens, who are proud of the connection of their ancient city with the association, welcomed the members with the greatest cordiality and hospitality. The meeting was favoured with exceptionally good weather, and as the programme left little to be desired, those who visited York on this occasion carried away with them very pleasant memories.

The old city looked its best. Socially, the meeting was everything that guests and hosts alike could have wished. The attendance at the meeting was 1959; that at the meeting in 1831 was 359.

We gave in our last number Prof. E. Ray Lankester's presidential address, as well as the names of the distinguished foreign men of science who attended the meeting, a number of whom received honorary degrees at Leeds University on Saturday, August 4.

The exhibition building proved very satisfactory; it would, in fact, be difficult to find a building better adapted for such a rendezvous. The reception room was adequate in all respects, and the great hall, handsomely decorated, had the appearance of a new building. Shrubs and bamboos | with a well-judged sprinkling of Lilium speciosum relieved the eye, and hanging baskets at intervals depended from the galleries. The best thanks of

citizens and visitors alike are due to the local secretaries, Mr. Charles E. Elmhirst and Mr. Henry Craven (Town Clerk of York), as well as to the acting secretary, Mr. Fred. Arey, whose experience in such matters proved invaluable

The two evening discourses in the great hall of the exhibition buildings were delivered by Dr. Tempest Anderson and Dr. A. D. Waller, F.R.S., the subject of the former being "Volcanoes," while that of the latter was "The Electrical Signs of Life, and their Abolition by Chloroform.' Large and attentive audiences packed the building, and showed every sign of interest in the subjects laid before them. The photographs of the late eruption of Vesuvius and its results were specially attractive.

The various sections were attended by large audiences, and offered so many subjects of interest that it is difficult to say which proved the most generally attractive. In many of the sections the presidents, in their opening addresses, dealt with the advance of science during the period of twentyfive years which has elapsed since the last meeting of the society in York.

on

At a meeting of the General Committee August 1, the report of the Council was read. Action has been taken by the Council in accordance with the recommendations made in the following resolutions from Sections A and H :

From Section A.-(1) The Committee, being of opinion that the completion of the Geodetic Arc from the South to the North of Africa is of the utmost scientific importance, and that the establishment of a Topographical Survey is of an importance that is at once scientific and economic, respectfully request the Council to make representations in such form as they think fit to urge upon the British South Africa Company the desirability of taking advantage of the present favourable opportunity for joining up the triangulation north and south of the Zambesi, and also to urge upon the Governments of the South African Colonies the immense practical and economic importance of commencing the topographical survey.

(2) The Committee desire to draw attention to the importance of a Magnetic Survey of South Africa, and respectfully request the Council of the Association to approach the Cape Government with a view to urging on them the great advantages which would accrue to Science and to South Africa if the Government would further support and assist the Survey which has already been partly made by Prof. Beattie and Prof. Morrison, and for the continuation of which a Special Committee of the Association is being appointed to cooperate with these gentlemen.

A grant of 300l. from the Special South Africa Fund has been made by the Council to Sir David Gill, for the purpose of completing the connection between the Rhodesian and Transvaal triangulations along the thirtieth meridian of East longitude.

From Section H.-(1) That it is desirable that the Governments of the South African Colonies be urged to take all necessary steps to collect, record, and preserve the knowledge and observations of men, such as missionaries, administrators, and others, who were living in intimate relations with the native tribes before the advance of civilisation began to obscure and even obliterate all true traditions, customs, and habits of the South African peoples; such steps to be taken without delay, especially in view of the old age and growing infirmities of most of the men referred to, and of the danger that with their deaths the knowledge which, if carefully recorded and preserved, would form a most valuable contribution towards the history of the aboriginal population, would irrecoverably lost; and that the Council be recommended to communicate with the South African Association and suggest the appointment of a committee to deal with the

matter.

be