carbide and calcium hydride respectively, and this not only prevents the burning away of the carbons, but actually increases their length slightly during operation.

A 750-volt dynamo supplies the three arcs in series, and there is means to regulate its pressure between 500 and 750 volts. Two choking coils (to prevent high-frequency currents from flowing back to the dynamo) and an adjustable resistance reduce the voltage at the terminals of the three arcs to between 250 and 350 volts. A current of from 3 to 4 amperes is employed.

FIG. 2.-The microphone and megaphone.

The diagram (Fig. 1) shows the connections of the microphone and the oscillatory circuit. The principal oscillatory circuit consists of an inductance and variable condenser, connected in parallel with the arcs A. An intermediate oscillatory circuit B, consisting of an inductance and variable condenser, is utilised to couple the principal circuit with the aerial, and ensures that multiple waves generated in the main circuit are not transmitted to the aerial, the result being that only a single wave is emitted. The aerial circuit

consists of an inductance coupled with the circuit B and a variable condenser. A variable selfinduction is also used in the aerial.

In the microphone circuit are nineteen carbon microphones connected in series, and so arranged that they are all acted upon by the voice simultaneously by means of a megaphone. The microphone and megaphone (drawn to different scales) are seen in Fig. 2; the large end of the megaphone covers the microphone. The microphone cells are connected between the variable inductance of the oscillation transformer and earth, as shown at C. This has the double advantage of avoiding sparking, such as always occurs in the microphones when they are placed directly in the aerial circuit, and does not limit the energy which can be taken by them. The station has two complete microphone equipments, with a changeover switch, so that each can be used for a short time and the other microphone allowed to cool, as naturally very large currents are employed.

The transmitting coils consist of flat spirals of copper strip, and the condensers are of the glassplate type. Arrangements are provided for very exact tuning by means of variable air condensers. The wave-length of transmission can be varied between wide limits; in the official tests a wavelength of 985 metres was used.

HIGH EXPLOSIVES IN WARFARE.

AT the present time explosives are playing such a prominent part in the war that the interest and attention of the most peace-loving citizen are necessarily aroused by the terrible results undoubtedly produced, or are more morbidly affected by the tales of the alleged marvellous effects which are yet to be experienced. A few notes on the most important explosives being used in war may therefore be of special interest just now.

The explosives which can be advantageously employed in warfare are by no means the most powerful which the chemist can produce, or which may even be used in civil engineering or mining operations. The military high explosive must be sufficiently insensitive to shock to prevent its being exploded when struck by projectiles, or when submitted to the shock of being fired from a gun as the charge of shell, else it might prove as dangerous to the user as to the enemy. Thus the nitroglycerine class and many other explosives are excluded.

For many years gun-cotton, containing a considerable amount of moisture, was largely used for naval and military purposes. In the moist state it is extremely safe, but can be easily detonated when a small primer of dry gun-cotton is fired in contact with it. The explosive effect is great, and it provided an excellent and safe explosive for military mines and purposes of destruction, and as a charge for torpedoes. It was not, however, suited for use in shells.

The high explosives chiefly being used in the present war for shell-filling are picric acid, trinitro

toluol, and ammonal. Picric acid, with or without the admixture of various ingredients, has been in use at one time or another in most countries under the names of melinite, lyddite, shimose powder, etc. Until picric acid came into use, black gunpowder formed practically the only explosive used as a bursting charge for shells, and the use of picric acid was a great advance from the destructive point of view, as its explosive power was very much greater. Picric acid, although sufficiently insensitive to shock, has the property of readily attacking metals and forming picrates, which are much more sensitive and liable to explosion. This involves special precautions in dealing with it, and is an undoubted disadvantage.

Ammonal is a mixture consisting of ammonium nitrate, trinitrotoluol, charcoal, and aluminium in fine powder. It is very safe, and is more powerful than picric acid, but owing to the hygroscopic character of ammonium nitrate, its chief constituent, it has specially to be protected from moisture, which reduces and, if in sufficient quantity, destroys its power of explosion. It is largely used by the Austrians.

Trinitrotoluol is undoubtedly now the most widely used high explosive for military purposes under the names of "Trotyl," "Tritolo," "Tolite," "Tritol," "Trilite," and "T.N.T.," according to the nation using it.

"T.N.T.," as it is called in the British Service, has attained its position by virture of its merits. It is used in a state of great purity; it is chemically stable and without action on metals. It is unaffected by water, and can be fused and run into shells in the molten state. It is less sensitive to shock than pieric acid. Hard blocks of suitable size and shape are covered by electro-plating them with a coating of copper, which prevents the blocks from being broken and having their edges chipped. In this form "T.N.T." is used for demolishing bridges, etc. Although not quite so powerful as picric acid, its other advantages make it at present perhaps the best available explosive for military use.

The destructive effect of an explosion is caused by the almost instantaneous conversion of the solid explosive into gases, at a very high temperature, with consequent sudden exertion of an enormous pressure. From the purely disruptive point of view, the composition of the gas produced is not necessarily of importance, the determining factors being the volume of gas, the heat produced, and the velocity of detonation. When however an explosion takes place in a confined space, then in addition to the disruptive or shattering damage, the components of the gas produced may have an injurious effect on anyone having to breathe it.

In the case of explosives for use in civil life, as in mining work, care is taken by adjusting the composition of the explosive that the gases produced shall not have a deleterious effect on the miner. In military operations this consideration does not arise; indeed, it may be maintained the more deadly the effect of the fumes the better.

Picric acid and “T.N.T.” are definite chemical

bodies, but owing to insufficiency of oxygen are not completely converted into gas on explosion, a considerable amount of carbon being set free. This accounts for the black smoke which is seen when these bodies are exploded.

In the earlier determinations, when explosives which contained insufficient oxygen for complete oxidation of the carbon and hydrogen were fired in a closed bomb, and the resulting gas analysed, it was found that its composition was affected by the density of loading. The higher the density of loading the higher the pressure, accompanied by increase of carbonic acid and decrease of carbonic oxide. Methane, which was absent or only in very small quantities at low densities of loading, increased steadily as the pressure increased. It was, however, recognised that the composition of the gas so found did not necessarily represent the composition at the moment of explosion, for the analysis was made some time after and when the gas had cooled. Consequently reactions had probably been taking place during the process of cooling. Finally, it was thought that the formation of methane was not a real result of explosion, but was due to secondary reactions during the cooling stage. The experimental difficulties of catching and fixing the gases at the moment of explosion were overcome by detonating the explosive in its own volume in a lead or porcelain bomb placed inside a larger evacuated steel bomb. The explosive had in this way to do work in bursting the smaller bomb, and the rapidity of cooling of the gas was thus so greatly increased that secondary reactions practically did not take place. When fired under these conditions, which correspond closely to those which exist when a shell explodes, the gases from ammonal, picric acid, and "T.N.T." were found to contain only small quantities of methane. In addition to carbonic acid, nitrogen, and hydrogen, ammonal contained about 24 per cent. and picric acid and "T.N.T." nearly 50 per cent. of the poisonous carbonic oxide. It is thus evident that where shells burst in confined spaces, in addition to the damage caused mechanically, those persons breathing the fumes may be fatally poisoned or seriously affected physiologically.

It has been suggested that the ingredients of shell charges may contain deadly poisons, but it seems improbable that any poison intentionally added to the contents of a shell would retain its toxic properties after the shock and heat of explosion. As seen above, the gases from the explosives now in use may be sufficiently poisonous under certain conditions.

The subject of explosives seems often to create a state of credulity, and to generate extravagance of statement on the part of the non-expert writer rarely effected by other matters. The unknown sometimes becomes truly appalling under his imaginative pen. Even inventors have been known to make wild statements in regard to their explosives! One should only accept with very many grains of salt the sensational statements which have appeared in some quarters as to the weird and deadly effects of recently-invented ex

plosives. It is well, therefore, not to have exaggerated ideas of the power of explosives or to be unduly scared by the threat of explosives dropped from Zeppelins. The destructive effect of the large charges which can be fired from the huge howitzers used in the present war is terrible, but explosives have their limits.

While without doubt the damage done locally from the explosion of a large quantity of any explosive which might be dropped by a Zeppelin would be appalling enough, yet, judging from the effects of the accidental explosion of a couple of tons of nitroglycerine during manufacture, its area would be comparatively restricted, and the horrifying suggestions mooted of the coming total destruction of cities by explosives dropped from the sky may be ascribed to the imagination of the over-credulous. W. MACNAB.

PROF. INGRAM BYWATER.

ON December 18 there died in his house in

Onslow Square the greatest Greek scholar of our time. Ingram Bywater was remarkable for the fact that he was imbued with the scientific spirit, and pursued the investigation of Greek thought--what may be called "the Greek thing" -in the true scientific method. He was in close sympathy with scientific men engaged in other branches of investigation, of the methods and results of which he had a remarkable understanding and appreciation.

Bywater was born in 1840, and after early days spent at University and King's College Schools, became a scholar of Queen's College, Oxford; then, in 1863, fellow and tutor of Exeter College. On the death of Jowett in 1893 he was appointed by Mr. Gladstone Regius Professor of Greek. It was chiefly through Bywater's influence that Exeter College was led to offer in 1872 a fellowship in the competition for which biology was to be the chief subject. Huxley and Rolleston acted as examiners on behalf of the College, and I had the good fortune to be the successful candidate. My college rooms were adjacent to Bywater's, and we became constant companions and friends. We often discussed-when the college slumbered-the life and learning of the world and our own special studies in a tobacco-parliament of two during the small hours of the night. I learnt more from him than I can say, and not only enjoyed his wise and humorous discourse and his freedom from pedantry, but formed a warm regard for his fine spirit, his wide learning, and his intellectual veracity. When my fellow-student Moseley-who had not competed for the Exeter fellowship owing to his appointment as naturalist on the Challenger expedition-returned from his travels, Bywater proposed that the college should elect him also to a fellowship, which was done.

In 1885 Bywater married the second daughter of Mr. C. J. Cornish, of Salcombe Regis, widow of Mr. Hans Sotheby, a former fellow of Exeter College. The work of her nephews, Charles and Vaughan Cornish, is well known to scientific

naturalists. Bywater was singularly happy in his marriage, and after the death of his wife in 1908 never recovered his strength and vivacity. He resigned his professorship, but still gave his services to the University in connection with the Bodleian and the Press. He lived among his books in his London house, where after my own departure from Oxford in 1898 I was his neighbour and constantly with him as in the old days at Exeter College.

He had a most unfavourable opinion of the study of Greek as conducted under the examination and scholarship system at Oxford. "It is not Greek which they study," he said, "but an arbitrary and unreal creation of the examination system and the traditions of college tutors." He complained that when he was professor even those more serious students among the undergraduates who might have profited by his teaching were by college directors of study kept away from his class-room, as they were in earlier days held back from the lectures of Max Müller. Bywater published in 1880 a remarkable piece of research and discovery relating to the fragments of the Greek philosopher Heracleitus, which led to his election as corresponding member of the Royal Academy of Sciences of Berlin. He devoted many years to the criticism of the text of the "Ethics and the "Poetics" of Aristotle, and in 1899 the Clarendon Press published his magnum opus, containing his recension of the text of the "Poetics" with an introduction, translation, and commentary. the young college tutors had the power of directing their pupils "not to waste their time" with listening to this great and original investigator, and, instead, to work up their Greek in the examination classes of the colleges; and they exercised it! Such is the mischievous result of the English university dry-rot-the examination system.

But

Only a month ago when my friend had temporarily rallied from the illness which has now ended fatally, he discoursed to me in his characteristically cautious yet vigorous style of German (more especially Prussian) arrogance and intrigue and the boasted "Kultur" of the Germans. He said that the quality of their abundant work, never very high, had deteriorated since 1870, and contrasted their grasping and pretentious attitude at the International Conference of Academies Vienna, where he represented the British Academy, with the charm and refinement of the leading Austrian delegate, Prof. Suess, the geologist, now also gone from us, who, he declared, justified his name by the sweetness of both his nature and his behaviour. E. RAY LANKESTER.

SCIENCE IN WARFARE.

in

WE reprint from the Daily Mail of December 18

a communication to that journal from a Belgian man of science showing how the Germans are utilising science for their operations in the newly conquered region in Belgium.

Here is a great lesson for us, for our Government cares too little for the nation's need for

science, which is as important for peace as for war purposes.

METEOROLOGY AND THE SCARBOROUGH RAID.

It is by no means surprising that for their raid on the three British coast towns the Germans should have profited so accurately by climatic conditions. When they first entered Belgium their army corps were immediately followed by the full staff of their observatories. On August 16 the astronomers and meteorologists attached to the Aix-la-Chapelle army corps took up their quarters at Liège, and on August 25 they were all at the Brussels Observatory at Uccle, where, on September 1, they were replaced by astronomers and meteorologists from Berlin.

Immediately on arriving at the Brussels Observatory the Germans turned out the Belgian staff. They made use of the Belgian instruments but supplemented them by the very up-to-date instruments they had brought from Berlin. On September 3 they began hunting for a Belgian hydrogen factory where they could obtain hydrogen for filling their testing balloons, by means of which they make their observations for predicting fogs. They used these balloons for forecasting the weather, particularly for the great German attack on Antwerp.

There is abundant evidence that the German men of science followed the same course with regard to the German raid on Scarborough, Hartlepool, and Whitby. They are admirably equipped for forecasting fog forty-eight hours ahead wherever they are. The German Army meteorological stations have certainly been transferred to Ostend and Zeebrugge. may not be as important as submarines, but these observation stations can render almost as effective aid in Germany's work of destruction as these engines.

NOTES.

They

M. C. E. GUILLAUME, the director of the Bureau des Poids et Mesures at the Pavillon de Breteuil, Sèvres, has made it known that the Institute of France has started a hospital, using for the purpose the funds at its disposal, and the voluntary contributions of its members. In Great Britain there are about thirty Associés Etrangers and correspondants of the institute, who have been notified of the action of the institute, and they have responded generously to the appeal of their French colleagues.

WE learn from Science of the death at sixty-four years of age of Dr. D. E. Salmon, chief of the U.S. Bureau of Animal Industry from 1884 to 1906.

WE regret to announce the death, at seventy-one years of age, of Mr. A. R. Hunt, of Torquay, fellow of the Geological and Linnean Societies.

WE regret to see the announcement of the death on November 10, at seventy-five years of age, of Prof. N. C. Dunér, secretary of the Swedish Royal Society of Science, Upsala, associate of the Royal Astronomical Society, and author of astronomical works of prime importance.

IT is announced that, owing to continued ill-health, Dr. E. F. Bashford has resigned the post of general superintendent of the Imperial Cancer Research Fund, which he has held for the past eight years, and that his resignation has been accepted by the executive committee.

THE Royal Geographical Society has arranged two On lectures to young people for the new year. January 4, Mr. C. Carus-Wilson will lecture on the earth's unstable crust; and on January 8 the Rev. T. T. Norgate will take as his subject the theatres of war, illustrated. The meetings will be held in the Kensington Town Hall, High Street, Kensington, at 3.30 p.m. Application for tickets should be made to the chief clerk, Royal Geographical Society, Kensington Gore, S.W.

Ar the fifth annual general meeting of the Society of Engineers (Incorporated), held on Monday, December 14, the awards of premiums made in respect of papers published in the journal of the society during 1914 were announced as follows:-The president's gold medal to Mr. A. S. E. Ackermann for his paper on the utilisation of solar energy; the Bessemer premium, value 51. 5s., to Mr. A. S. Buckle for his paper on cylinder bridge foundations in the East; the Clarke premium, value 51. 5s., to Mr. S. M. Dodington for his paper on mechanical appliances for the painless killing of animals; the premium, value 31. 38., for members of affiliated societies, to Mr. R. H. Cunningham (Crystal Palace Engineering School) for his paper on irrigation in India; a society's premium, value 21. 2s., to Mr. James Tonge for his paper on uses of the hydraulic mining cartridge. Mr. Norman Scorgie was elected president of the society for 1915.

THE Royal Institution has circulated an illustrated brochure which explains for popular purposes the nature and objects of the institution. The institution was established under a charter of George III. in 1800, and enlarged and confirmed by an Act of Parliament in 1810. The objects of the foundation are "to prosecute scientific and literary research; to illustrate and diffuse the principles of inductive and experimental science; to promote social intercourse among lovers of science, men and women; and to afford them opportunities for collective and individual study." It is not necessary to insist upon the value to the world of the scientific work accomplished in the laboratories of the Royal Institution, when the names of a few of the great men who have worked there are recalled: Davy, Faraday, Tyndall, to say nothing of living men of science. The hope may be expressed that there will be no diminution of the usefulness and popularity of the institution in view of the war, but that its influence may become increasingly powerful as the years pass.

A DISTINGUISHED traveller and servant of the Empire has passed away in Archibald Ross Colquhoun, who died on December 18. He was born in 1848, and his earliest civil service was in the Indian police. From this he passed to the public works department, and then became secretary to a Government mission to Siam, and the Siamese Shan States. Later he was Deputy Commissioner of Upper Burma, but before this, in 1881-82, he made an important journey from Canton to Bhamo, investigating the possibilities for a Burma-Chinese railway route, and also acted as a special correspondent in the French war in Tongking (1883-84). Afterwards, having left Government ser

44

vice in the East, he came into contact with Cecil Rhodes, served with the South African pioneer force, and became administrator of Mashonaland in 1890. In later years he travelled extensively and wrote much on South Africa, on the Far East, on the Pacific and the Panama Canal schemes, and on other topics. Some of his books are important contributions to the study of great political questions, such as The Key of the Pacific (on the Panama Canal routes), "China in Transformation," "The Mastery of the Pacific," and "The Afrikander Land." He was closely associated with the work of the Royal Colonial Institute, and was editor of its journal, and among various honours he received the gold medal of the Royal Geographical Society.

THE organised methods employed by Germany in commerce, and the means necessary to meet them successfully, were referred to by Sir William Ramsay in an article contributed by him to NATURE of November 12 (p. 275). Sir William deals with the same subject in further detail in a paper just issued by the Institute of Industry and Commerce (Aldwych Site, Strand, W.C.) The German military organisation has its counterpart in their commercial organisation; there exists an Imperial Council the proceedings of which are kept quiet, but which takes into consideration all obtainable statistics, and so far as possible legislates, or endeavours to legislate, on the basis of these statistics. Where fiscal duties are found to be required, such a council puts them on; where there is an advantage in taking them off, they are removed. Where cheap transit is possible they give it; for the railways are the property of the State. In referring to these matters at the annual meeting of the Society of Chemical Industry in 1903, Sir William Ramsay said:"Is it to be expected that any country can fight such a combination as that without adopting, at all events, something of their methods, or without studying their methods, and without combining together, if not to imitate them, at least to thwart them? There is a military campaign against us, and we must defend ourselves." Sir William points out that it will be necessary, if the future German State is allowed to retain the power of waging an industrial war, to combat it by the action of the organised British nation, that is, by the State. Once that conquest is achieved, we should do well to remember that commerce should be co-operative and not competitive; that it is to our interest not only that we ourselves should prosper, but that others should also prosper; that, indeed, our own prosperity is bound up in the prosperity of our fellow-creatures.

THE Philadelphia meeting of the American Association for the Advancement of Science will open on Monday, December 28, when the retiring president, Prof. E. B. Wilson, of Columbia University, will introduce the president of the meeting, Dr. C. W. Eliot, of Harvard. Addresses of welcome by the provost and the governor-elect will be replied to by President Eliot, after which retiring President Wilson will deliver his address on "Some Aspects of Progress in Modern Zoology." There will be two public lectures, complimentary to the citizens of Philadelphia

and vicinity, one on Tuesday night, at 8 o'clock, being by Dr. D. C. Miller, "The Science of Musical Sounds.". On Wednesday night, at 8 o'clock, Dr. W. H. Nichols will lecture on "The War and the Chemical Industry." The titles of the addresses by the retiring presidents of the sections are as follows:Physics Recent evidence for the existence of the nucleus atom, A. D. Cole; Botany: The economic trend of botany, H. C. Cowles; Anthropology and Psychology: The function and test of definition and method in psychology, W. B. Pillsbury; Mathematics and Astronomy: The object of astronomical and mathematical research, F. Schlesinger; Agriculture: The place of research and of publicity in the forthcoming country life development, L. H. Bailey; Education: The American rural school, P. P. Claxton; Engineering: Safety Engineering, O. P. Hood; Geology and Geography: The relief of our Pacific coast, J. S. Diller; Physiology and Experimental Medicine: The classification of nervous reactions, T. Hough; Social and Economic Science: Social and economic value of industrial museums, J. G. Wall; Zoology: The research work of the Tortugas Laboratory of the Carnegie Institution of Washington, A. G. Mayer; Chemistry: Fermentation, C. S. Alsberg.

66

Ar a good old age-eighty-six-the famous Swiss guide, Melchior Anderegg, has passed to his rest. Born near Meiringen, at which place he died, he was bred and lived, except when undertaking some longer excursion, in the Oberland. He was introduced, if we remember rightly, to the Alpine fraternity by the late T. W. Hinchliff, who described, in his delightful Summer Months among the Alps," excursions with him across the Strahlegg Pass in 1855 and up the Altels in the following year. Melchior's "great ascents" were rather more than twenty, for his employers, among whom we may number the Walkers, father, son, and daughter, A. W. Moore, H. B. George, F. Morsehead, C. E. Mathews, and Leslie Stephen, belonged to the old guard of Alpine climbers and did not consider the charms of an expedition enhanced by needless perils. The more notable of those ascents were Mont Blanc by the Aiguille and Dôme du Goûter, and by the more difficult route from the Brenva glacier; the Col de la Tour Noire, a most laborious pass, near the Aiguille d'Argentière, and the Roththal Sattel, one yet more dangerous, under the Jungfrau; the highest peak of the Grandes Jorasses, the Dent d'Hérens, the ParrotSpitze of Monte Rosa and its culminating peak by a new route up the Grenz glacier, but probably there were very few of the more noted peaks and passes of the Alps with which Melchior was not acquainted. Besides this, he was an expert wood-carver, and small statues of friends from his chisel have more than once been exhibited in England. Melchior deservedly won the affection of all who had travelled in his company. He was one of nature's gentlemen, and the late C. E. Mathews, whose companion he had been for thirty-four years, truly says in his "Annals of Mont Blanc" that he was "perhaps the greatest all-round guide whom the love of mountaineering has ever produced. . . . It is with a peculiar pleasure and