SCIENCE AND ART. TELEPHONE AND TELEGRAPH.-M.J.Coudray, telegraphist, of Montreux, in a little brochure, describes a remarkable electric phenomenon that lately came under his observation. Two years ago, at the instance the proprietor of the Hotel des Alpes, at Territet-Chillon, he placed that establishment in telephone communication with a châlet on the hill-side, about 500 mètres above the hotel. The conducting wire was insulated in the usual way by glass, and the circuit completed through the earth. When he applied his ear to the telephones, M Coudray often heard crepitations, similar to the sounds observed in telephones the conducting wires of which run parallel and close to the wires of a telegraph. But as the telephone in question is at right angles to the telegraph. which runs on the railway by the lake side, and is separated from it by a distance of 80 to 100 mètres, there being no other wire in the neigh borhood, M. Coudray ascribed these crepitations at first to the possible contact of the telephonic wire with the branches of trees, whereby a thermo-electric current was induced. He soon, however, saw reason to abandon this theory, for one morning in the month of May last, being at the Hotel des Alpes, he put his ear to the telephone and heard the sound of messages which were being sent through the post-office wires on the railway, 100 mètres distant, so clearly that he was able to distinguish the purport of two, one of which was being transmitted from Montreux to Geneva, the other from Ouchy to Monthey, in the Valais, but in order to read messages it is necessary that there should be only one going at the time, and the very moment of its passage should be seized by the listener. This is a conjunction that rarely occurs. When two or more messages are in course of transmission the result is merely crepitation, and not intelligible words. M. Coudray's explanation of the phenomenon is as follows:-The electric circuit, as is well-known, is completed by the earth-that is a current sent from A to B through a wire returns from B to A by the earth. If an isolated piece of wire be placed on any part of the ground traversed by a current and connected with a telephone, an infinitesimal, albeit sufficient, current is derived from the earth to actuate the telephone. Physicists and electricians have hitherto denied the existence of terrestrial currents, holding, rather, that the earth, acting as a reservoir of electricity, balances the electricity at the two extremities of the wire; but M. Coudray thinks the facts he had observed prove that electric currents circulate in the soil just as if it were a metallic botly. The second of his conclusions is, that the secrecy of telegraphic messages, whenever there is a telephone in the neighborhood of the wires, cannot be considered inviolable. In practice, however, the difficulty of distinguishing them will probably be a sufficient bar to impertinent curiosity.- London Times. OBSERVATIONS OF THE AURORA.-An interesting report on systematic observations of aurora, at 132 Northern stations, under Herr Tromholt. at Bergen, during 1878-9, has been lately published. The stations were situated between 71° 7′ and 55° 3′ N. lat. It appears that there were but very few evenings on which the aurora was not observed somewhere (though the year was a minimum one). Herr Tromholt also concludes that polar light is often a pretty local phenomenon, and developed at but a little height above the earth's surface. Unfortunately the data as to height are but scanty; the best give o'24, 0'25, and o'15 of a geographical mile above the earth. As to frequency, the following figures are given : 71° to 68°, 100; 68° to 65°, 30'6; 65° to 62°, 18'2; 62° to 59°, 126; 59° to 55°, 7.6. The region affected by an aurora is found to be generally by no means large. Only thrice was aurora observed on the same day at different stations, and it is a question if it was the same aurora in each case. Herr Tromholt thinks he has found a connection between frequency of aurora and phases of the moon, but a longer series of observations as to this is desirable. A comparison with the magnetic variations at Upsala led to no result: as also a comparison with meteorological phenomena. Herr Tromholt has never perceived aught of noise accompanying aurora. Cer COLOR BLINDNESS.-At the last meeting of the Ophthalmological Society a report was presented by a committee of sixteen members recently appointed by the Society. No less than 18,088 persons have been examined, of whom 1657 were females. The average percentage of color defects among these latter was 4, that of the males being 4'76, the pronounced cases only among males being 3'5 per cent. tain classes of persons show an exceptionally high percentage of color defects. The most striking in this respect are deaf-mutes, among whom every fifth child is defective. The average is also higher than normal among members of the Society of Friends, especially among those belonging to the poorer classes. It is distinctly high among Jews, and the forms of color-blindness occurring among these are very pronounced. The secretary attributes color defects in some cases to a congenital physical defect, either in eye or brain, occurring as an accidental variation from the normal structure. When once existing it is capable of being transmitted to descendants. In other cases he thinks that they may arise, more especially the slight forms, from defective education in colors in infancy. This might account for the superiority of the female sex in respect to colors. It would also account for the high percentage exhibited by the deaf and dumb, and to some extent for that of members of the Society of Friends. It would also be compatible with a greater prevalence of color defects among the poor. The third factor, which is by no means an unimportant one, is intermarriage. He is strongly of opinion that among Jews, and to a less degree among Friends, intermarriage during generations has strengthened the defects existing among them not only in number but in degree. THE TURQUOISE IN PREHISTORIC TIMES.Under Pliny's name of Callais, M. Damour some years ago described a greenish mineral, apparently a variety of turquoise, which had been found, worked into ornamental forms, in some of the dolmens of the Morbihan, and had evidently been employed for purposes of personal decoration in prehistoric times. M. Cazalis de Fonduce has had occasion to examine a large number of objects worked in this material, and found not only in various parts of France, but also in Portugal. Thus M. Ribeiro obtained no fewer than 214 beads of callais in his exploration of the artificial grotto of Palmella. M. Cazalis de Fonduce has collected all the facts connected with the subject, and has contributed an interesting paper to the last number of M. Cartailhac's Matériaux pour l'Histoire de l'Homme. He believes that the callais, or turquoise, must have been imported into Western Europe from the East, probably toward the close of the Neolithic period; at any rate, it was largely used at the commencement of the Bronze age. It is difficult to speak definitely as to the ethnical characteristics of the prehistoric people who used this material, but it is suggested that they may have been the Ligurians, the Indo-European precursors of the great Keltic invasion. VISIBLE CIRCULATION OF THE BLOOD.-To Düter, of Greifswald, is attributed the first visible demonstration of the circulation of blood in the human body. In this operation, the patient's head being fixed in a frame having a contrivance for supporting a microscope and a lamp, his lower lip is drawn out and fixed on the stage of the microscope by means of clips, the inner surface being uppermost, and having a strong light thrown upon it by a condenser. This arrangement being complete, all the observer has to do is to bring the microscope to bear on the surface of the lip, using a low power objective, and focussing a small superficial vessel at once he sees the endless and wonderful procession of the blood corpus cles through the minute capillaries, the colorless ones appearing like white specks dotting the red stream. The various amounts Now, to com PHOTOGRAPHIC PHOTOMETRY.—A promising application of photography to precise measurement of phenomena of light has been recently tried by M. Janssen. The method is advantageous in that photography reveals the action of the extremely weak luminous and the ultraviolet rays; but the chief advantage lies in the permanence of the results as against the fugitive nature of ordinary photometric comparisons, which, too, require the simultaneous presence of the two light sources. of metallic deposit on the photographic plate cannot well be weighed, so M. Janssen measures by the degree of opacity produced. His photometer consists of a frame with sensitized plate, before which is passed at a known rate of uniform motion a shutter having a slit. If this slit were rectangular, a uniform shade would be produced on the plate; but by making it triangular he obtains a variation of shade, decreasing from the side corresponding to the base of the triangle to that corresponding to the apex. It is further proved that the photographic deposit does not increase as rapidly as the luminous intensity. pare the sensibility of two plates differently prepared they have merely to be exposed successively in the frame under like conditions, and the points where they show the same opacity being compared to the points of the triangular slit corresponding to them, the ratio of the apertures at those points expresses the ratio of sensibility. Thus the new gelatino-bromide of silver plates are proved to be twenty times as sensitive as the collodion plates prepared by the wet process. Again, to compare two luminous sources, they are made to act successively on two similar plates in the photometer, and the points of equal shade in the plates indicate, as before, the relation sought. M. Janssen has compared the light of the sun and some stars on these principles, preparing from the former" solar scales" (with uniform degradation of shade), under exactly determined conditions as to sensitive layer, time of solar action, height of the sun, etc. Circular images of stars are obtained by placing a photographic plate a little out of focus in the telescope, and a series of these, got with different times of exposure, are compared with the scales obtained from sunlight. M. Janssen will shortly make known some of his results. LOCALIZING BY THE EYES.-At the recent meeting of the Physical Society, Professor Helmholtz, of Berlin, gave an account of the factors which enter into our ability to fix the position and distance of an object by the eyes. That the binocular effect is not all-powerful is shown by the fact that single-eyed persons can estimate distance about as well as those with two eyes. A person suddenly blinded, however, has to acquire the new art of judging by one eye. This consists, according to Professor Helmholtz, of two elements, namely, the appearance of the objects with respect to other bodies, and the parallel of motion. The outlines of the more distant objects are always covered by those of the nearer ones where they cross, and hence the difficulty of recognizing that the image projected by a convex lens or a concave mirror is nearer to the observer than the lens or the mirror. Further, the object which projects a shadow upon any surface is always situated before that surface. These two elements go to make up the appearance of the objects, and they are really overpowered by others, for example, stereoscopic combinations. This is demonstrated by Dove's pseudoscope, an instrument composed of two rectangular prisms, and showing to each eye a reflected image inverted from right to left. The parallax of motion is seen as a shifting of the object, especially if it is near, on moving the head from side to side or up and down. This element also overpowers the stereoscopic combination of the images of the two eyes. MISCELLANY. BEACONSFIELD UNDER STRESS OF FEELING.— Those who closely watched the health of the deceased gentleman during the last fifteen years particularly cannot fail to have noticed the struggle which has been maintained by the mind against, and to some extent at the expense of, the body. While Mr. Disraeli sat in the House of Commons his life was an almost continuous effort. His imperturbable bearing, his habit of emotional self-restraint, his almost uniformly placid style of delivery-artistically, and always as the result of purpose, never involuntary, varied by lighter and brighter passages of elocution were the fruits of effort. The statuesque posture, the motionless face, the abstracted or seemingly indifferent manner which the superficial observer mistook for indications of a constitutional lack of sensibility, were, in truth, tokens of the intensity of the emotional nature they disguised. Lord Beaconsfield was a man of profoundly deep feeling and a highly sensitive temperament, but with an indomitable will, habituated to self-control, the customary expressions of such feeling as he possessed were interdicted. For example, in place of movements of the ordinary excito-motor type, the noble Lord's physicial habit was in the later-middle period and toward the end of his career in the Commons characterized by slight and seemingly automatic but really conscious acts of the slightest kind often repeated. It was very curious and profoundly interesting to study these movements from the psychological standpoint. Under ordinary circumstances, Mr. Disraeli would sit for long stretches of time during the violent or terribly irritating attack of a political opponent with nearly closed eyes, as though asleep. When the onslaught waxed furious, he would, as though with all-engrossing intent, fix his gaze at the toes of his boots, moving them slowly so as to bring all points under observation. If the taunts or reproaches hurled at him were of so grievous a nature as to make any other man furious, he would straighten himself and brush some particle of dust from the front of his buttoned frockcoat or from the sleeve of his left arm. Then he would examine his nails, and as a climax, when few statesmen so assailed could avoid some token of emotional restlessness, he would perhaps take out his single eyeglass, and fixing it firmly, look for an instant at the clock in the front of the gallery opposite Mr. Speaker, dropping the glass with one quick elevation of the eyebrow this lastmentioned trick being the only part of a series of actions which, though familiar to his observers, was never a mere matter of habit. Probably--and it is worth noting in reference to the recent incident of his approaching the Ministerial bench in the House of Lords after the division at the close of the Candahar debate -the noble Lord was less a man of habit in the true sense of the term-that is, as implying the relegation of large classes of actions to the sub-consciousness, to be performed automatically-than the average brain-worker. The fact is interesting as throwing light on the type of his physico-mental constitution, and as illustrating the character of strain which the life and enterprise of the deceased statesman imposed on his mind-power. It was practically too late when Mr. Disraeli became Earl of Beaconsfield to prolong a valued life by the means adopted. Speaking now freely, we believe the deceased statesman would have lived longer if he had not thus late retired to a scene of comparative quiet upon which he ought, in the interest of his health, to have entered when the queen urged him to do so some years before. As it was, Lord Beaconsfield was deprived of his accustomed mental stimulus at the precise moment when he most needed it, and, although his immediate personal feelings were those of relief, the physical ease was purchased at too great a price. Street, at 4.30, on the morning of Tuesday, the 19th inst. His illness had always been more serious than his physicians admitted, there being a visible want of recuperative power in the system, but for the three or four days preceding Monday the soft spring weather benefited him so much that even the doctors had hope. On Sunday, however, the bitter east wind was again raging, the thermometer fell to 40°, and in the evening of Monday Lord Beaconsfield sank into a state of partial coma, or heavy sleep, from which he never wholly revived. Just before he died, however, he "raised himself from the pillows, threw back his arms, expanded his chest, and his lips were seen to move, as if he were about to speak," the whole action producing in those who watched him a conviction that he thought himself again in the Commons, rising to some great effort of debate. Then he sank down, the difficult breathing ceased, he drew a few regular inspirations, and so, as calmly as if in sleep, he died. He had throughout little hope of recovery, but he feared death as little as any other opponent ; his mordant humor broke out at intervals, and, though usually silent, he sometimes conversed with all his old clearness and incisiveness upon public affairs. He was a childless man, almost a kinless one, but his oldest friends were about his bedside; the man he liked best, Lord Rowton, was with him to the last; and what he would have preferred to all things, Europe was listening for tidings from his room. His death, like his life, was far from an unhappy one.— The Spectator. Realities of WAR.-A popular writer thus describes a battle: "We have been fighting at the edge of the woods. A moment ago the battery was a confused mob. We look again, and the six guns are in position, the detached horses hurrying away, the ammunition chests open, and along our line runs the command, Give them one more volley, and fall back to support the guns.' We have scarcely obeyed when boom boom! opens the battery, and jets of fire jump down and scorch the green trees under which we fought and struggled. The shattered old brigade has a chance to breathe, for the first time in three hours, as we form a lane and lie down. What grim, cool fellows those cannoneers are! Every man is a perfect machine. Bullets splash dust into their faces, but they do not wince. Bullets sing over and around, they do not dodge. There goes one to the earth, shot through the head as he sponged his gun. That machinery loses just one beat, misses just one cog in the wheel, and then works away again as before. Every gun is using a short fuse shell. The ground shakes and trembles, the roar shuts out all sound from a battle-line three miles long, and the shells go shrieking into the swamp to cut trees short off, to mow great gaps in the bushes, to hunt out, and shatter, and mangle men until their corpses cannot be recognized as human. You would think a tornado was howling through the forest, followed by billows of fire, and yet men live through it-aye, press forward to capture the battery. We can hear their shouts as they form for the rush. Now the shells are changed for grape and canister, and the guns are fired so fast that all reports blend into one mighty roar. The shriek of a shell is the wickedest sound in war, but nothing makes the flesh crawl like the demoniac singing, purring, whistling grape-shot, and the serpent-like hiss of canister. Men's legs and heads are torn from bodies, and bodies cut in two. A round shot or shell takes two men out of the rank as it crashes through. Grape and canister mow a swathe and pile the dead on top of each other. Through the smoke we see a swarm of men. It is not a battle-line, but a mob of men desperate enough to bathe their bayonets in the flame of the guns. The guns leap from the ground almost as they are depressed on the foe, and shrieks and screams and shouts blend into one awful and steady cry. Twenty men out on the battery are down, and the firing is interrupted. The foe accept it as a sign of wavering and come rushing on. They are not ten feet away when the guns give them a last shot. That discharge picks living men off their feet and throws them into the swamp, a blackened, bloody mass. Up now, as the enemy are among the guns! There is a silence of ten seconds, and then the flash and roar of more than 3000 muskets and a rush forward with bayonets. For what! Neither on the right nor left, nor in front of us is the living foe! There are corpses around us which have been struck by three, four, and even six bullets, and nowhere on this acre of ground is a wounded man! The wheels of the gun cannot move until the blockade of dead is removed. Men cannot pass from caisson to gun without climbing over rows of dead. Every gun and wheel is smeared with blood; every foot of grass has its horrible stain. Historians write of the glory of war. Burial parties saw murder, where historians saw glory." NATURÆ PENETRALIA. A SLUGGISH little stream, that loiters slow Of small red bitterns, sitting patiently, With mighty limbs outstretched and half-shut eyes, H. C. I. THE march of democracy is not limited to mankind alone; the uprising of nouvelles couches is not confined to the peoples of the earth; the undermining of the upper classes is not restricted to humanity. The dismantling of aristocracies is no longer a merely mortal operation; it has sapped away the bases of other privileges than those of princes; it has exterminated other prerogatives than those of blood; it has suppressed other rights than those of birth. The revolutionary spirit is swelling beyond politics and parliaments; its action is stretching outside societies, and is reaching above nations; it is pervading nature herself, and is even permeating matter. The subversiveness of our time extends to metals as well as to men; under its dissolving action-alas that we should have to say it !-steel has ceased to be a gentleman. Until this nineteenth century steel had retained its exalted place. It had been assailed by gunpowder, and it had been NEW SERIES.-Vol. XXXIV., No. 2 debilitated by the gradual diminution of duels, but it had held its own; its superb traditions had not yet faded; the knightly sword was still its accepted expression, still its representative idea. It is true that steel-though used in Asia from all time-though seen, perhaps, in imperial Rome, and though introduced into Spain by the Arabs in the ninth century-had only been seriously known to Europeans since the First Crusade ; it is true that the swords of Greece, of Spain, of Germany, of Gaul, contained no sign of it: but for the last eight centuries the world had learned to associate the sword and steel together, and to instinctively regard them as implying the same conception. To-day, that stately unity has disappeared. The sword has been dethroned; and steel, meanly forsaking its former self, repudiating its lineage, its alliances, and its traditions, has gone in for demagogy. And we are the sad spectators of its fall. What a superb career it has renounced! ΙΟ |