the cylinder and thus build up the picture. The fidelity of the reproduction will depend as before on the closeness of the spiral and the accuracy with which the receiving drum corresponds in speed of rotation to the transmitting drum. In practice, the drums are rotated at a speed of about thirty revolutions per minute, and the apparatus operates with such speed as to record three hundred sharplydefined chemical marks per second. Accordingly, a picture of considerable size may be built up Injecting anti-typhoid vaccine into the arm of a soldier. The use of this vaccine in the United States army has been attended with such striking success that it has now been made obligatory for all soldiers under the age of forty-five about a cylinder, which is with the electric circuit. When the cur- The vaccine-therapy method of a certain number of them into the veins of the by the endless spiral of graduated marks in the course of a few minutes. Stated otherwise, only a few min in the very early was not unnaturally amused that a discovery made by him in Massachusetts should have remained quite unnoticed in this country until an account of it was brought to New York by Marconi wireless from England. The explanation is found in the fact that the transatlantic message came as an announcement from Greenwich Observatory and therefore seemed to have official importance that the proclamation of a mere professor of astronomy could not hope to attain. The discovery itself has a high degree of interest. It concerns the nebulous rings that give unique distinction to the planet Saturn. Professor Todd describes the discovery thus: "Near the extremities of the major axes of the bright outer ring of Saturn, with the aid of a powerful telescope, I have observed a certain sparkling flocculence which I interpret to be a dissipation of the ring." Professor Todd has further explained that the discovery does not indicate any recent change in the composition of characteristics of the ring; but merely that he has been The Rings of Saturn ACURIOUS illustration of the old saying about the prophet in his own country was given recently by a newspaper dispatch from London, announcing to the New York public a discovery made by Professor David Todd of Amherst, Mass. Professor Todd By submitting them for fifteen minutes to electric currents, Mr. Lowitz has caused seeds to germinate. Wheat stimulated by electricity has grown six inches in three weeks able to observe conditions not hitherto noted. The discovery is due to the favorable position of Saturn at the present time and to Professor Todd's use of a very superior telescope having an 18-inch glass, made in 1905 by Alvin Clark & Sons. The exact significance of the observed "sparkling flocculence" may perhaps be open to different interpretations. The simplest explanation, perhaps, is that the detached particles of matter-"brickbats" Clerk-Maxwell called them-that make up the rings of Saturn come more or less into collision as they circle about, and that the observation of the sparkling at the extremities of the major axes of the outer ring and not elsewhere is merely an optical effect. Similar collisions producing sparkling flocculence doubtless occur in all portions of the rings, but their presence is obscured by the general luminescence. The new observation has chief interest, perhaps, as an additional item of evidence that the rings of Saturn are actually composed of detached fragments of matter. To be sure, no astronomer has doubted this, since Professor Peirce of Harvard showed mathematically, in '1851, that were the rings solid, they must fall of their own weight; and particularly since Clerk-Maxwell made his famous computations reducing the puzzling rings to a cloud of meteoric particles, each fragment circulating exactly as if it were an independent planet. Further evidence to the same effect was given by the spectroscope in the hands of the late Professor Keeler, then of the Allegheny Observatory, who tested with the spectroscope the flight of the mass of meteorites making up the rings. But notwithstanding the fairly dependable knowledge that had thus been gained, Professor Todd's direct observation confirmatory of the nebular character of Saturn's rings has distinct importance. Canary-Birds as Danger Signals THE danger from noxious gases is one free even in the best ventilated mines. A new method of testing the presence of these gases was tried at the Bryceville, Tennessee, mines recently, after an explosion through which more than a hundred miners were entombed. The rescuers employed by the United States government carried cages of canary-birds, and were enabled to gauge the condition of the atmosphere through observation of the birds. It is stated that the birds began to gasp for breath and drop from their perches, overcome by the inhalation of the poisonous gases, before the miners had other evidence that the atmosphere was vitiated. Men were able to enter any parts of the mine where the birds gave no evidence of suffering; but beyond the point where the birds began to succumb, only men equipped with oxygen machines could safely go. This is perhaps not surprising, for it is well known that the temperature of the bird is higher than that of the human being, and it might reasonably be inferred that the bird would require a relatively large supply of oxygen. Moreover, the matter has recently been put to an experimental test by Dr. Florence Buchanan, of University College, London, who has shown that small birds in particular consume relatively large quantities of oxygen. Her experiments were made by measuring the quantity of carbon dioxide given off in given off in a given time by different birds and animals, and making the comparison general by reducing the results to a unit standard of weight. It was found that the canary consumes a quantity of oxygen relatively almost twenty times as great as the quantity consumed by a man. oxygen supply required by small animals, and in particular the mouse, was found also to be very high. As might be expected, the pulse rate of these small creatures is excessively rapid, that of the canary averaging one thousand beats per minute. The Dr. Buchanan, some time since, called attention to the fact that carbon monoxide, the most dangerous of the gases formed when explosions or fires occur in mines, neither affects the sense organs nor produces pain, and therefore may cause the death of a miner who has had no warning of its presence. She credits Dr. Haldane with first suggesting that a mouse or small bird in a cage should form as much a part of a miner's equipment as a safety-lamp. She calculates for a man at rest, and seven to eight times as long for a man at work, to be disabled as for a mouse; and the small bird is even more sensitive. A practical application of these scientific experiments has now been made, as we have seen. If the test was really as definitive as the reports seem to show, it may be expected that canary-birds will become a part of the regular equipment of all mines where the intrusion of noxious gases is a possibility. The oxygen-making machine, with which the rescuers in mines are now equipped, does not differ in principle from those long in use, but has a very important practical modification that does away with the cumbersome helmet and air-tight suit similar to a diver's suit, which has hitherto been necessary. The essential modification of the new equipment consists of an apparatus adjusted to the mouth and nostrils, which permits breathing from tubes connected with an oxygen-generating tank carried on the miner's back, and which obviously permits unrestricted action of the arms and body. It is an interesting question whether a modification of the same apparatus may not be applicable in the case of the submarine diver. In any event, the apparatus should be provided for use in an emergency on submarine boats, somewhat as life preservers are supplied to the ordinary sea-goer. Growing Plants by Electricity NOT long ago, Mr. Emile Lowitz gave a demonstration before an audience at the Royal Botanic Society's Gardens near London of the effect of electricity upon the germination of seeds. An ordinary dynamo supplied the current, and the electricity was directly applied through zinc and copper plates placed in the ground on either side of the seeds. The seeds were thus submitted for ten minutes to a current of eighty volts; then for five minutes to two thousand volts. When a seed thus treated was placed under a microscope, it could be observed that the embryo had begun to germinate. To produce in this way an effect that ordinarily requires days or weeks has obvious. scientific interest, and suggests equally obvious advantages for the market gardener. The electric current has further utility in that it destroys any germs of plant disease or embryos of grubs or other injurious insects that may be in the ground. It is even possible to destroy the insect pests on trees by this method. It has for some time been known that the growth of the developing plant could be markedly influenced by the electric current. In his Royal Botanic Garden demonstration, Mr. Lowitz showed wheat that had grown six inches in three weeks and other prodigies that owed their development to stimulus with the electric current. Similar demonstrations have been made at various places, but experiments conducted at Dahlen, Germany, have peculiar interest because the comparative tests took into account the normal electricity of the atmosphere. The plants tested were the ordinary garden vegetables, such as spinach, cabbage, and lettuce. Plants grown in the open, neither artificially stimulated with electricity nor protected from the electricity of the atmosphere, were taken as the standard. Another group of plants was subjected to intensified atmospheric electricity induced by currents from overhead wires. This increased the yield by from fifteen to forty per cent. The beneficial effect of overcharging the atmosphere with electricity being demonstrated, a question arose as to what would be the effect of reducing the normal electricity in the atmosphere. A test was made by growing dwarf French beans under a wire cage, so arranged as to take the natural electricity from the atmosphere by conducting it to the ground. Plants grown under these conditions showed a yield of about fifteen per cent. below the normal. It appears, then, that the normal presence of atmospheric electricity is a factor in plant growth that hitherto has been largely overlooked. The matter has a high degree of popular interest because any amateur gardener who has the most elementary knowledge of electricity may string wires across his garden. plot and thus force the growth of his vegetables and fruits. It is reported, for example, that the ripening of strawberries may thus be hastened by several days. As to the practical application of the current, it is found that the morning and evening hours are best; in spring and autumn, say from 7:30 to 9:30 A. M., and for two hours before dusk. It is not necessary to apply the electricity during bright sunshine; and it is useless to apply it during a rain. Foggy weather, however, is very favorable. The ease with which the electricity may be applied should give the method general popularity among market gardeners; and the prospect of securing earlier and better vegetables from his garden plot and hotbeds should make obvious appeal to the amateur. |