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E. N. Browne, in the August number of the Journal of different types of flora are provided by the rocks, meadows, Experimental Zoology (vol. vii., No. 1), dealing with the and swamp, and in certain parts there are areas of ling production of new hydranths by the insertion of small and sphagnum moors. Among the rare plants to be found grafts from another individual of the same species. This are Mulgedium alpinum, Rhodiola rosea, Luzula spadices, paper is particularly interesting on account of the ingenuity two species of Isoetes, and Subularia aquatica. of the methods employed. In order to determine the exact
THE Bio-chemical urnal for Septem! (iv., No. 8) origin of the regenerating material, the author makes use of Whitney's discovery that the green colour can be entirely clature of lipoid substances. He proposes to classify them
contains a paper, by Dr. Otto Rosenheim, on the nomenremoved from Hydra viridis, without killing the animal, by in three main groups, the cholesterins, the cerebrokeeping it for some weeks in a 0.5 per cent. solution of galactosides, and the phosphatides. Prof. Moore and Drs. glycerin. The artificial white hydras thus produced form
Wilson and Hutchinson contribute a paper on the bioperfect grafts with ordinary green forms, giving rise to
chemistry of hæmolysis. parti-coloured colonies in which the boundaries between the tissues of the green and white components remain clearly PROF. HALLIBURTON, in the Journal of Hygiene (vol. ix., defined.
No. 2, September), directs attention to the fact that large Irish Gardening (October) contains various seasonable quantities of flour, both in this country and abroad, are articles, notably on the cultivation of seakale and the artificially bleached. Some experiments he has performed gloxinia. A very charming bell-shaped ericaceous plant, distinctly indicate that both the starch and the gluten are
rendered less digestible by the process of bleaching, though Zenobia speciosa, is recommended for the garden by Mr.
whether the change is sufficient to be serious to children or C. F. Ball; in the variety pulverulenta it attains to the
invalids is a question on which there is at present no dimensions of a good-sized bush. It requires a peaty soil
evidence. or the nearest equivalent, and is propagated from seed or by layers.
IN the Bulletin of the Johns Hopkins Hospital for The Country Home (October) appears in an enlarged
September (xx., No. 222), Dr. Charles White discusses in
a suggestive manner the municipal management of tubercuform from the offices of the Sphere and Tatler.
losis. He points out that our struggle must be for an botanical and zoological articles are chiefly utilitarian or
immune race, not for the extermination of the last tubercle popular. The intensive cultivation of asparagus is explained by Mr. L. Terasse, and vegetative propagation of small doses in healthy resistant bodies. In municipali
bacillus. More and more we see the evidence of protection forms the subject of an article by Mr. W. M. Webb, while Mr. H. B. Buchanan gives advice on the breeding of pigs.
ties the aim should be to get rid of sources of large doses
of tubercle bacilli, and to establish resistant bodies by FOLLOWING up a line of work instituted in the United healthy lives, mainly in the children. States of America, the examination of parasitic fungi that AN account of the mathematical work of Sully Prudattack scale insects has been taken up by the Department homme is given by Prof. H. Poincaré in the Revue of Agriculture for the West Indies. Three species of générale des Sciences for August 15. Sully Prudhomme Ascomycetes, Sphaerostilbe coccophila, Ophionectria cocci
received a scientific education in his youth, but was precola, and Myriangium Duriaei are specified in the Agri- vented by ill-health from attending the École polytechnique. cultural News (September 18) as having been taken on scale insects infesting lime or citrus trees in Dominica, mathematics is evidenced by the numerous manuscripts
That he nevertheless gave a large amount of attention to St. Lucia, and other islands, and a fourth fungus is noted, left by him, including the rough drafts of a memoir on but not identified. It is proposed to experiment with geometry. It appears, however, that the manuscripts now cultures of these fungi on nutrient media which could be | in existence cannot be regarded as more than rough drafts distributed to cultivators.
of ideas which Prudhomme had further developed and conThe most striking point in a description of fungus siderably modified after writing them. Prof. Poincaré maladies of the sugar-cane, prepared by Dr. N. A. Cobb, concludes that it would be undesirable to publish them and published in Bulletin No. 6 of the division of patho- in extenso, and he therefore devotes the concluding portion logy and physiology in connection with the Hawaiian of his paper to a general account of their salient features. Sugar-planters' Association, is the attribution of parasitism Under the title of “ The Gambler's Ruin " (Annals of to the phalloid fungi Ithyphallus coralloides and Clathrus Mathematics, X., 4), Prof. J. L. Coolidge discusses certain trilobatus. The mycelium of Ithyphallus found
problems connected with games of chance which have not attached to cane trash and the roots, while the mycelium hitherto received complete treatment. It is pointed out that of Clathrus passed in among the roots of canes where while the problem of determining the odds that one player disease was abundant, so that the author classes them with
may ruin another has been worked out thoroughly for the species of Marasmius as sources of root disease. With
case where the amount staked at each turn is the same, the the view of identifying the mycelium of these Phalloideæ, a case where the stakes are varied, whether they be limited special study was made of their sphæro-crystals.
or unlimited, has been less fully discussed. The author IN . connection with visit of German systematic considers the systems proposed at Monte Carlo and botanists, Dr. E. Issler prepared an account of vegeta- elsewhere, and gives a deductive proof that no such system tion conditions in the Central Vosges Mountains, which is
can have more than an easily calculable chance of success. published in Engler's Botanische Jahrbücher (vol. xliii.,
He concludes with the quotation from Sir Hiram Maxim's part iii.). The formations distinguished in the montane
book :-" Je me rends parfaitement compte du désagréabk region are spruce, beech, mixed fir woods, and the vegeta
effet que produit sur la majorité de l'humanité, tout ce qui tion of the forest streams. It is a curious fact that the se rapporte, même au plus faible degré, a des calculs ou beech in many places ascends higher than the conifers, raisonnements mathématiques." the reason being that the upper tree limit, at the low A SYSTEMATIC study of the influence of the surroundaltitude of 4000 feet, is determined by the wind, which the ing medium on the lines of the spark spectrum has been beech is better able to withstand. In the subalpine region undertaken by Dr. H. Finger at the suggestion of Prof.
Konen, of Münster, and his principal results are streams, formed in the drainage area before any definite marised in No. 17 of the Verhandlungen der deutschen line of principal stream has been settled.” Accounts are physikalischen Gesellschaft. A comparison has been made given of places and objects of scientific interest visited between the spectra of more than twenty metal electrodes during excursions, and among these is a record of an in air and in water, the spark being produced by an excursion to Shepton Mallet and Vallis l'ale, which is induction coil of 40 cm., having a capacity of 0.02 micro- well known for its romantic scenery and geological unfarad in parallel with its spark gap. The spectra in air conformities. The report contains the accompanying illusand in water were pliotographed on the same plate, a tration, reproduced by permission of the council of the concave grating of radius 180 cm. being used. The spectra Geological Society, of the classic section showing Oolite in water show no air lines, but a large proportion of them resting upon Carboniferous Limestone, which was pictured show a more or less extended continuous spectrum with by Sir H. de la Beche. Short papers by Messrs. L. the lines of water vapour reversed. Some lines are un- Richardson and C. Cpton, and a report by the Rev. H. J. changed, while others are broadened on one or on both sides, Riddelsdell, on the progress made in connection with the lines belonging to the same series being modified in the flora of Gloucestershire, complete the issue.
No trace of the spectra of salts in solution Le Radium for August contains a very useful table of in the water has in any instance been detected.
the principal minerals containing uranium and thorium, Part iii., vol. xvi., of the Proceedings of the Cotteswold prepared by M. B. Szilard, of Madame Curie's laboratory. Naturalists' Field Club maintains the high standard of It occupies seven pages of the periodical, and gives the style and illustration which distinguishes this publication. name, the composition, the percentages of uranium and of
A large part is concerned with the record of excursions thorium, the localities in which the mineral is found, and chiefly to places of geological or antiquarian interest, and its crystalline form. In addition, a map of the world, in is illustrated by no fewer than nine plates of photographic which the localities are shown, is given. reproductions. Of the papers published, the longest is on MR. HAROLD MOORE, of Woolwich Arsenal, read a paper “ The Lower Severn : Valley, River, and Estuary from the on the Brinell method of determining hardness at the InterWarwickshire to the Bristol Avon," by Mr. T. S. Ellis. national Association for Testing Materials. We note from The principal aim of the author is to show that the
an abstract in Engineering for October 8 that the author's generally accepted views of river development associated results show that the thickness of the test specimen has with the name of Prof. W. M. Davis are not applicable no influence on the result provided that the depth of the to the district with which he deals, and by inference to impression made by the ball does not exceed one-seventh other districts also. His position is indicated by the follow the thickness of the specimen. A safe rule to be adopted ing sentence :-“As I believe, we cannot have a right is that the distance of the centre of the impression from conception of the development of rivers unless we keep our the edge of the specimen should not be less than 2.5 times minds free from all idea of original lines of streams or of the diameter of the impression. For calculating the hardany principal line as the initial condition. In my view, ness number, 30° should be chosen as the standard angle a river system is evolved not into, but from a network of of impression, this giving a diameter of impression equal
to one-half the diameter of the ball. The hardness number recorded and illustrated by MM. Quénisset and Antoniadi then becomes the mean pressure per unit area when the
in the October number of the Bulletin de la Société
astronomique de France. Numerous canals were observed, diameter of the impression is one-half the diameter of
the Solis Lacus was seen to be divided, and important the ball. 'In practice it is convenient to employ a known changes in the colour and visibility of various regions were load, and measure the diameter of the impression obtained. closely followed. M. Antoniadi is confirmed in his opinion The hardness number is then calculated from the formula that these changes are caused by the passage of Martian
clouds across the various features, and, from the yellowish 16PD--2
tinge which colours the indistinct areas, he confirms the (2d)"
opinion expressed by Prof. W. H. Pickering in 1905, that where P is the load in kilograms, D is the diameter of the these Martian clouds are probably yellow. ball, d is the diameter of the impression, and n is a Solar OBSERVATIONS : A Novel SPECTROSCOPE.-In order coefficient determined by making two impressions with the to continue his solar observations, Mr. W. M. Mitchell same ball and different loads, and applying the formula found it necessary, at the Haverford College Observatory,
to devise a large spectroscope which might be used in log P, - Ing P
conjunction with a small equatorial. The telescope at log d, - log d
Haverford is of 10 inches aperture and 12 feet 6 inches A REVISED impression of Sir Robert S. Ball's little
focal length, and cannot, therefore, carry a large, and work “ Time and Tide" has just been issued by the
consequently heavy, spectroscope of the ordinary type.
Acting upon a suggestion from Prof. Hale, he has erected Society for Promoting Christian Knowledge.
a spectroscope which is mounted upon, and is parallel to, A CHEAP edition of “Extinct Animals,” by Sir E. Ray
the telescope tube, and finds that the device answers Lankester, K.C.B., F.R.S., lias been published by Messrs.
very satisfactorily. The beam from the 10-inch objective
is reflected on to the slit of the spectroscope by a 90° Constable and Co., Ltd. The original edition of the work prism, and, passing through the slit, is again reflected was reviewed in Nature of November 2, 1905 (vol. Ixxiii., | by a similar prism on to a 3-inch collimating lens of No. 1879).
39 inches focal length. Thence it passes to a grating and
back through the 3-inch lens to the eye-piece, the grating We are in receipt of a new catalogue of books and
and lens being slightly tilted. A negative lens placed papers (more than 1400 in number) dealing with ornith- between the 10-inch objective and the first reflecting prism ology which Messrs. John Wheldon and Co., of Great gives a larger image, which in Mr. Mitchell's observations Queen Street, W.C., have for disposal.
was of 3.2 inches diameter. The spectroscope tube is
constructed of wood, saturated with hot paraffin before The October classified list of second-hand scientific assembling to obviate subsequent warping. instruments offered for sale or hire by Mr. Charles Baker, With this instrument Mr. Mitchell gets a resolving of High Holborn, has reached us. The catalogue, which power of 70,000 in the third-order spectrum, and was able contains upwards of 1300 items, will be sent free of charge An interesting observation on May 11 showed that at one
to observe visually the Zeeman effect in sun-spot lines. upon request.
end of a spot “ bridge ” certain lines were doubled, whilst MM. A. HERMANN ET Fils, of Paris, have published a
at the other end, the farthest from the centre of the spot translation into French, by Dr. Paul Lemoine, of Prof.
group, the same lines were triple; other lines were double James Geikie's “ Structural and Field Geology," which
in both regions. A list of lines, recorded as bright in a was reviewed in these columns on July 6, 1905 (vol. Ixxii., hromospheric outburst on January 21 7h. to gh. G.M.T.,
is also given, and Mr. Mitchell urges the necessity for p. 223). M. Michel-Lévy has contributed a preface. The more laboratory work in connection with chromospheric price of the French work is 15 francs.
We regret to learn that astronomical observations are A new edition (the eighth) of “Quantitative Chemical
to be suspended at the Haverford Observatory, and, conAnalysis," by Clowes and Coleman, has been published sequently, Mr. Mitchell's observations cannot be continued. by Messrs. J. and A. Churchill at 10s. 6d. net. The work
THE AURORA OF SEPTEMBER 25.-In No. 4361 of the has been revised and enlarged, but the size of the page Astronomische Nachrichten (p. 287, October 7) Herr having been increased the thickness of the volume re- Torvald Köhl records that a fine display of the aurora mains as before.
was observed at Odder, Denmark, on September 21, and
adds that a similar display was observed in Stockholm on MESSRS. CONSTABLE AND Co., Ltd., have sent
September 25. cheap edition of “ Time and Clocks," by H. H. Cunyng- SEPTEMBER METEORS.—The appearance of a magnificent hame, C.B. A review of the first edition appeared in fireball on September 27d. 7h. 2om. is recorded by Herr the issue of NATURE for January 17, 1907 (vol. lxxv., Köhl, who observed it at the Carina Observatory, Odder, No. 1942).
in No. 4361 of the Astronomische Nachrichten. Herr Köhl finds from his meteor-catalogue that he observed
similar apparitions on September 27-28 in ten different OUR ASTRONOMICAL COLUMN.
years between 1870 and 1909. He also has records of Mars.-The advisability of watching Mars closely, at
meteors December 12-13 for eleven years between this period of favourable opposition, and seasonal changes 1875 and 1908. on the planet itself, is illustrated by a brief message com- HYDROGEN LAYERS IN THE Solar ATMOSPHERE.-In the municated to the Astronomische Nachrichten (No. 4362, Comptes rendus for September 20 (No. 12, p. 521) MM. P.- 303, October 9) by M. Jarry Desloges. Whilst the Deslandres and d’Azambuja review the work which has planet was; being observed at gh. 15m. on October 6, a been done in separating the various layers of calcium projection was seen on the terminator in the neighbour- vapour in the sun's atmosphere, and describe the results hood of Electris. ' This projection lasted for ten minutes of similar researches on the hydrogen and iron vapours only, whilst a similar one observed by Messrs. Lowell and recently carried out at Meudon. Slipher, on May 25, 1903, endured for only thirty-one The image, obtained by using the centre of the Ha line, minutes ; the latter was ascribed to a cloud of dust some differs from the Mount Wilson photographs, and shows 300 miles in length.
the details, exactly, of the K, calcium images, the same In No. 4361 of the same journal M. Jonckheere dark filaments and the same bright areas. The authors announces the discovery, on September 28, of a canal | suggest that the Mount Wilson images were produced by which is probably a new one, and extends from Cyclopum mistures of the different parts of the Ha line, and that Lucus to Hephæstus; the same observer records a further the sinuosities in the edges of the various sections might observation of the new land “Stella on October 7.
produce this effect. In the dispersion used at Meudon A large number of observations of different features are
I mm. = 6 Å.
water-channels, dense crops of the erect plumose awns of PERGY SLADEN MEMORIAL EXPEDITION
Aristida seeds, forced beneath the surface by their hygroIN SOUTH-WEST AFRICA, 1908-9.' scopic movements, were commonly seen. So unusual a II.
supply of food had tenipted into the vicinity of the town
springbok, gemsbok and other antelopes, while ostriches IN the latitude of Loanda (8.90 S.), behind a dry; sparsely had reappeared after an absence of many years. Very
populated coastal belt about 150 miles wide, lies a large Welwitschia plants were found in abundance about mountainous zone, for the most part densely forest-covered eight miles to the south of Mossamedes in the direction
of Cape Negro, the locality in which it
discovered by Welwitsch. The plants had coned freely, but almost without exception the cones, severely attacked by a fungus (probably a Cladosporium), were in a state of decomposition-no doubt another consequence of the excessive atmospheric humidity earlier in the season. A large number of young seedlings were found. The Damaraland localities previously referred to, in which no Welwitschia seedlings have been found within recent years, are about forty miles from the sea.. But even in these southern latitudes normal seed-reproduction seems to occur on the coast. A recent letter from Dr. Hintrager, Acting
Governor of German South-West Africa, contains the interesting statement that “ wenige Kilometer nordöstlich von Cape Cross' die Welwitschia noch häufig und in fast allen Alterstadien, also auch in jungen Pflanzen vorkommt.” It is not improbable that a condition of its seed-germination in nature is a degree of atmospheric humidity which is constantly realised
near the sea though now usually absent Fig. 1.-A glade in the Bauhinia forest showing a Baobab just before the beginning of leal-fall
from desert places inland.
On April 27 I left Mossamedes with
the intention of crossing the Huilla to an elevation of 4000 feet. Within this zone is the plateau and reaching the Cunene River. I was accomhistoric locality of Golungo Alto, where Welwitsch lived panied by Mr. H. G. Mackie, H.B.M. Consul in Angola, for two years, and in which a large part of his rich to whose kind support the success of this part of the collection was obtained. Here he discovered Gnetum journey was very largely due. The light railway, at africanum in 1855.
present working to the 107th kilometre, leaves Mossamedes A few inilcs to the south-east of Queta, a station on in a northerly direction and crosses the broad beds of the the railway within the forest zone and not far from its periodical rivers Bero and Giroual, in which, near the sea, eastern edge, is situated the Government experimental plantation (Granja San Luiz), under the energetic direction of Mr. J. Gossweiler, to whom I am indebted for valuable advice and assistance during my residence there from April 1-12. The forests are here very dense and the undergrowth thick and very varied in character. After an cessful search of some days' duration, Gnetum was eventually found on April 7 in a very dense and dark forest on the coffee and rubber estate of Montobello (2600 feet), some thirty miles to the west of Granja San Luiz and ten miles south west from the railway station of Queta. It was very abundant within a strictly limited area and its occurrence is clearly “ sporadic,” as described by Welwitsch. It may be noted that the native name “N-coco” given by Welwitsch is now applied indifferently to various plants of climbing habit; of Gnetum itself the natives seem to have no special knowledge.
Leaving Loanda on April 16, I arrived on April 21 at Mossamedes, where the third section of the journey commenced.
Fig. 2.-Cunene marshes opposite Fort Roçadas, looking north. Quite exceptional rains had recently fallen here, as in so many other districts to the south, and a few tropical and subtropical crops are cultivated. So the gently rising plains behind the town resembled a waving far inland as the present railhead, the rainfall is small and cornfield rather than a desert. They supported a thick, inconstant and, in normal seasons, the country is pracuniform growth of a tall Aristida (? A. prodigiosa, Welw.), tically waterless. At about 80 km., however, the typical among which there flourished a considerable number of desert vegetation mingles with shrubs and a few dwarf small annuals. In sandy places, especially in shallow, dry. tices, which are found in greater luxuriance on the lower 1 The fir-t article appeared in NATURE of October 14.
i Lat. 219 S.
slopes of the Chella Range. The railhead is situated in The country at its foot is thickly studded with small an open forest of stunted trees, among which Acacias, Baobabs and away to the east the open Acácia and a Bauhinia and the Baobab are prominent, with wide, Bauhinia forest again prevails, and undoubtedly merges grass-covered glades. This formation extends to the lower farther south into the thorn-bush of Ovamboland and the slopes of the Chella Range becoming denser as it ascends | Acacia park-formation which extends fat to the south of until, near the summit, it effects a junction with a Okahandya and Windhuk. Savannah, the characteristic species of which include a I take this opportunity of acknowledging the effective number of Proteaceæ and other southern forms. The support which has been very kindly given to the objects western face of the Chella Range rises sheer to of the expedition by Their. Excellencies Sr. Capt. H. 3000 feet from the forest which clothes its base, above de Paiva Couceiro, Acting Governor-General of Angola ; which the bedding planes of its grey, lichen-covered sand- Herr Regierungsrath Dr. Hintrager, Acting Governor of stone are plainly visible. Except for its great extent, the German South-West Africa ; and the Hon. W. F. Helywhole range bears a striking resemblance to Table Moun- | Hutchinson, G.C.M.G., Governor of Cape Colony. tain as seen from Table Bay. Opposite Capangombe there
H. H. W. Pearsox. is a gap, the entrance to a kloof up which winds a steep footpath to the top through an increasingly dense, dripping forest, with a magnificent undergrowth of maiden-hair and
MODERN METHODS OF ILLUMINATION.1 other ferns. Near the summit a tall Euphorbia with the habit of E. grandidens occurs in great abundance. A GREAT change has come over the methods of lightLeaving the Boer village of Humpata (6000 feet) on
ing within the last few years. We have now at our May 10, we approached the Cunene along the now well- disposal means of lighting which would have seemed inknown track down the valley of the Caculovar. On credible a few years ago. Step by step with these descending the eastern slopes, which are less steep than developments has taken place the progress of education the western,
we passed through the same changes of and the increase of printed matter, with the result that flora, in the reverse order, as those already observed we use our eyes to-day far more than in the past. Our
main object, therefore, should be to corsider the subject of illumination from the point of view of the impression received through the eye. After emphasising this aspect of illumination, Mr.
Gaster proceeds with a surnmary of whiteli Huilta
recent developments in electric lightThalia
carbon filament glow-lamp could be R Alexander
made to yield more efficient results by bringing it to a higher temperature, i.e. running it at a pressure higher than that ordinarily utilised, but such a gain in efficiency has only been found
possible at the expense of life and Tiger Bey
Within the last few years we have PERCY SLADEN
seen the development of lamps with
filaments made of other and more reMomonal Arnedition
fractory materials, such as the Nernst South West Africa 1900
lamp, and the various metallic filaHection 3
ments, such as osmium, iridium, tanplachways Kaoko lelad
talum and tungsten, &c. The two lastRoute
named lamps, of course, now play a Olamboland Kilom a
great rôle in electric lighting.
In addition, attempts have been made to improve carbon filaments in the
C'nited States by the graphitising prothe other side. Passing the Huilla Mission- cess of Mr. Howell, by the aid of which a consumption of the scene of the botanical labours of Fathers Antunes and 2.5 watts to 3 watts per candle was attained. Another Dekindt-we arrived on May 13 at Chibia (4500 feet), interesting attempt in this direction is the Hopfelt lamp, where the proteaceous flora thins out and gives place in which the carbon filament burns in an atmosphere of again to the open, dry forest, in which the Bauhinia and mercury vapour, with, it is stated, a consumption near Acacias in turn predominate. Henceforward the surface, , 1.5 watts per candle. The Helion lamp, again, is believed frequently broken by tumbled heaps of gneiss and iron- to utilise a filament mainly composed of silicon ; it is stone, 50 feet to 500 feet high, slopes gently down to the claimed to run for 1000 hours at I watt per candle, and Cunene. From Gambos (4100 feet) the water-supply, after even in the open air, without requiring to be enclosed in an the end of the rainy season (April), is meagre and its evacuated globe ; but it has not yet come upon the market. quality bad, and the whole district is fever-stricken. The Perhaps the best known metallic filament lamps in use at temperature becomes very high after mid-day, and whirl- the present day are those utilising the metal tantalum winds of great violence spring up very suddenly, and carry and those described by various names, but generally columns of dust and other light objects to great heights. believed to contain as the main constituent the metal Three hours by waggon from Houmbe brought us to the tungsten. Tungsten lamps are burned at a consumption Cunene marshes, which are here conñned to the right approaching 1 watt per candle-power, and are generally bank of the river. Owing to the unusually late rains stated to have a life, under good conditions, of 1000 burnthey were still nearly two miles wide, and it was with ing hours. One great difficulty, however, has been the great difficulty that a crossing to Fort Roçadas on the manufacture of lamps of moderate candle-power for high opposite bank was effected. This stronghold is placed upon voltages, and capable of being used in any position ; very the high calcareous cliff forming the left bank of the river. recently, however, lamps having as low a candle-power as Its neighbourhood, the scene during recent years of many 25 or 30, and for pressures extending to 200 volts to 260 engagements between the Portuguese and the trans-Cunene Ovambo tribes, has become so extremely unhealthy that
1 Abstract of a series of four Cantor lectures delivered by Mr. LED
Gaster before the Royal Society of Arts and published in the Journal of the it will in future be manned entirely by native troops: Society for August 6, 13, 20, 27; September 3, 10.