THE MONTH: SCIENCE AND ARTS.

Professor Janssen, the well-known astronomer of Meudon Observatory, who has done more than any man living, perhaps, towards wedding the photographic camera with the telescope, has lately published some account of a marvellous picture which he obtained of ‘the old moon in the new moon’s arms.’ At the time that the picture was taken, the moon was only three days old, and an uncovering of the lens for one minute only was sufficient to secure the image. This image is feeble, but is full of detail, plainly showing the general configuration of the lunar surface. Professor Janssen believes that this application of photography points to a means of obtaining more precise measurements of the light, and of studying the phenomena which are produced by the double reflection of the solar light between our earth and its satellite. To the uninitiated, in these days of marvellous instantaneous pictures, an exposure of one minute may seem rather a long period. But let us consider for a moment what a very small proportion of the sun’s glory is reflected to us from the moon, even on the finest nights. Professor Sir W. Thomson gives some interesting information on this point. Comparing the full moon to a standard candle, he tells us that the light it affords is equal to that given by such a candle at a distance of seven feet and a half. As in the above-mentioned photograph the light dealt with came from a moon not full, but only three days old, it will be seen that Professor Janssen had a very small amount of illumination for his picture, and the only wonder is that he was able to obtain any result at all.

It will be remembered that in the autumn of 1882, a series of observations were commenced in the polar regions, which had been organised by an International Polar Committee. Fourteen expeditions from various countries took up positions in that inhospitable area, with the intention of carrying out observations for twelve months, from which it was hoped that valuable knowledge would be gained. This programme has been successfully carried out, ten of the expeditions having returned home, many of them laden with rich stores of observations. Three remain to continue their work for another year. As to the return of the remaining band of observers—belonging to the United States—there is as yet no definite information.

On Ailsa Craig, Firth of Clyde, there is being erected, by order of the Commissioners of Northern Lights, a mineral-oil gas-work, to supply gas for the lighthouse in course of construction there, as well as to feed the gas-engines which will be used to drive the fog-signalling apparatus. The works are being erected by the patentee of this gas-system, Mr James Keith, and will cost three thousand pounds. They will be capable of manufacturing two thousand cubic feet of oil-gas per hour, of fifty-candle illuminating standard. It has long been the opinion of many that the electric light is not the best illuminant for lighthouse purposes, and this installation at Ailsa Craig, following one on the same principle at the Isle of Man not long ago, would seem to indicate that the authorities think so too.

North-east of Afghanistan there lies a piece of country called Kafiristan, which, until April last, had never been traversed by the foot of a European. In that month, however, Mr W. W. M‘Nair, of the Indian medical service, crossed the British frontier, and travelled through the little-known region for two months. An interesting account of his wanderings formed the subject of a paper read by him at a recent meeting of the Royal Geographical Society. The country is inhabited by three main tribes—Ramgals, Vaigals, and Bashgals, answering to the three chief valleys, and each having a distinctive dialect. The men are warlike and brave, but, like many other semi-barbarous peoples, leave the heavy work of agriculture to the women. The Mohammedans hem them in on all sides; but as the tribes are at peace among themselves, they are able to hold their own. Slavery exists to some extent. The people acknowledge one supreme being, Imbra, and worship at temples presided over by priests; but to neither priests nor idols is excessive reverence paid. Bows and arrows form their chief arms; and although a few matchlocks have found their way into the country from Cabul, no attempt has been made to imitate them. Wealth is reckoned by heads of cattle; the staple food is wheat; and the favourite drink pure grape-juice, not rendered intoxicating by fermentation or distillation.

Although there is every reason to believe that cruelty to animals is far less common than it was, still there are many men who are not so merciful to their beasts as they might be. Many of these offend from ignorance, and will leave poor creatures exposed to inclement weather under the belief that they will not suffer. Professor Shelton, of the Kansas State Agricultural College, has lately shown, by careful experiment, that it pays to be merciful in the matter of providing shelter for pigs; and we have no doubt that if his researches had been extended to other animals, a similar result would have been obtained. For this experiment, ten pigs, as nearly as possible alike with regard to breed, age, &c., were chosen, five being kept in a barn, and five in the open, but provided with straw to lie upon. These two families were fed twice a day with carefully weighed messes of Indian corn. In the sequel, it was found that each bushel of corn produced in the barn-fed pigs ten and three-tenths pounds of pork, whilst each bushel given to the outsiders formed only nine and seven-tenths. This result of course clearly shows that a large proportion of the food given went to keep the outdoor pigs warm, instead of adding to their flesh. If the bucolic mind will only grasp this fact, we feel sure that more attention will be given to the question of shelter for animals.

Professor Cohn, writing from Breslau to Nature, calls attention to the circumstance that just two hundred years ago there was made in the Netherlands a scientific discovery of the greatest importance. In the year 1683, Leeuwenhoek gave notice to our Royal Society that by the aid of his microscope he had detected in the white substance adhering to his teeth ‘very little animals moving in a very lively fashion.’ ‘These,’ says Professor Cohn, ‘were the first bacteria which the human eye ever saw.’ The descriptions and drawings given by this first observer are so correct, that even in these days, when the Germ theory of disease has brought forward so many workers in the same field, armed with much improved appliances, the organisms drawn by the hand of Leeuwenhoek can be easily recognised and compared with their fellows of to-day. These drawings have indeed never been surpassed till within the last ten years, a fact which speaks volumes for their accuracy and value.

The buildings occupied by the International Fisheries Exhibition at South Kensington are, in 1884, to be devoted to a no less important object, albeit it is not likely to be so popular with the masses. This Exhibition will deal with matters relating to Health and Education. It will include the food-resources of the world; the best means of cooking that food; the costumes of the world, and their bearing upon health; the sanitary construction of dwellings; and many other things that every one ought to know about, but which very few study. With the Prince of Wales as President, assisted by a Council including the names of Sir Cunliffe Owen and Mr Birkbeck, the success of the scheme ought to be assured.

In Cannon Street, London, an experimental section of roadway of a novel kind has lately been laid down. It is the invention of Mr H. F. Williams, an engineer of San Francisco, where the system has been most successfully employed for the past seven years. Indeed, the roads so prepared are said to be as good as when first laid down, allowing for a reasonable amount of wear and tear. The process is as follows. First of all is provided a good dry concrete foundation; upon this are laid blocks of wood, grain-end uppermost, measuring eight inches by four, with a thickness of an inch and a half. Each block, before being placed in position, is dipped halfway into a boiling mixture of asphalt and Trinidad bitumen; this glues the blocks to the foundation and to one another, at the same time leaving a narrow space all round the upper half of each piece of wood. This space is afterwards filled in with boiling asphalt. Above all is spread a half-inch coating of asphalt mixed with coarse grit, the object of which is to prevent that dangerous slipperiness that is common to asphalt roadways in moist states of the atmosphere.

At Brooklyn, the sanitary authorities seem to have a very sensible method of dealing with milk-dealers in the matter of adulteration. They invited the dealers to meet in the Common Council Chamber, when it was explained to them by an expert how they could determine by various tests whether the milk purchased from the farms is of the required standard. At the conclusion of this conference, it was hinted that the licenses of such dealers as were thenceforward detected in selling adulterated milk would be peremptorily revoked.

At the end of December last, the first of four large silos on Lord Tollemache’s estate in Cheshire was opened in the presence of a large number of farmers and scientific agriculturists. It had been filled with dry grass, chopped into inch-lengths by a chaff-cutter, and pressed down with a weight equal to fifty-six pounds on the square foot. The appearance of the ensilage was that of dark-brown moss, having a pleasant aroma; but, as in other experiments of the kind, the top layer was mouldy and spoiled. Lord Tollemache stated that he found that animals did not seem to care for the fodder when first offered them, but that they afterwards ate it with evident relish. Several samples of ensilage were exhibited at the late Cattle-show in London, and it is noteworthy that almost without exception the pampered show-animals, when a handful was offered them by way of experiment, took the food greedily. On Mr C. Mackenzie’s farm of Portmore, in Peeblesshire, a silo was opened in December, the contents of which—pressed down while in a moist condition—were found to be excellently suited for feeding purposes.

It is worthy of notice that the past year brought with it the fiftieth anniversary of the lucifer-match, which was first made in this kingdom by John Walker of Stockton-on-Tees in 1833. The same year, a factory was started at Vienna; and very soon works of a similar character sprang up all over the world. In 1847, a most important improvement was made in substituting the red amorphous phosphorus for the more common variety. This modification put an end to that terrible disease, phosphorus necrosis, which attacked the unfortunate matchmakers. The strong agitation which this disease gave rise to against the employment of phosphorus, naturally directed the attention of experimenters to other means of striking a light; and although phosphorus in its harmless amorphous form still holds its own, it is probable that its presence in lucifer-matches will some day be dispensed with. We need hardly remind our readers that the universal adoption of the electric light would greatly curtail the use of matches, for that form of illumination does not require an initial spark to set it aglow.

Some artillery officers in Switzerland have been putting their snow-clad mountain flanks to a curious experimental use, for they have been employing one of them as a gigantic target for their missiles. A space on this snow-covered ground measuring two hundred and thirty feet by ninety-eight feet—which would represent the area occupied by a battalion of infantry in double column—was carefully marked out, its centre being occupied by flags. At a distance of about a mile, the artillery opened fire upon this mapped-out space until they had expended three hundred shots. The ground was then examined; and the pits in the snow when counted showed that seventy-eight per cent. of the shots had entered the inclosure. Had a veritable battalion occupied the ground, there would have been few, if any survivors.

In another experiment, snow was employed as a means of defence against artillery. A wall sixteen and a half feet long, and five feet high, was built of snow having various thicknesses, but backed by half-inch wooden planking. This wall was divided into three sections, having a thickness respectively of four and a half feet, three feet, and twenty inches. Against the thickest section, twelve shots were fired from various distances; but in no case was penetration effected. In the three-foot section, shots pierced the snow as far as the woodwork, where they were stopped. In the twenty-inch section, all the shots fired went completely through the wall. It would seem from these experiments that snow, when available, can be made a valuable means of defence. But, unfortunately, in the published account of the experiments, the calibre of the guns employed is not given; we should, however, assume them to be field-artillery of a very light type.

A new use for the ubiquitous dynamo-electric machine is reported from Saxony, and one which seems to fulfil a most useful purpose—namely, the ventilation of mines. At the Carola pits, Messrs Siemens and Halske, the German electricians, have inaugurated this new system. At the pit bank, a dynamo is stationed, which is coupled up by shafting with the engine. By means of copper conductors, this machine is connected with another dynamo, two thousand five hundred feet away in the depths of the mine. This latter is connected with a powerful centrifugal fan. The cost of working these combined machines is six shillings and threepence per day, which means threepence for every million cubic feet of air delivered.

A new employment for the electric light has been found in Bavaria, where a Committee has reported upon its use as a head-light for locomotive engines. The colour and form of signals can be distinguished by the engine-driver on a cloudy night at a distance of eight hundred feet. The light burns steadily, and is not affected by the motion of the engine; but a special form of arc-lamp is employed, the invention of H. Sedlaczek of Vienna. The lamp is so constructed that it moves automatically when the engine traverses a curve, so as to light the track far in advance. The dynamo is placed just behind the funnel, and is easily connected with the moving parts of the machinery by suitable gearing.

The new patent law which came into operation on the first of January will without doubt give a great impetus to invention in this country, for many a man too poor to think of employing a patent agent, and paying down nearly ten pounds for a few months’ protection, as he had to do under the old conditions, can easily afford the one pound which is now the sum fixed for the initial fee. Moreover, a would-be patentee can obtain all necessary forms at the nearest post-office, and can send in his specification through the same medium, without the intervention of the ‘middle-man.’ Of course the law cannot be perfect enough to please every one, and a few months’ practice will probably discover many points in which it can be improved. One curious provision has put certain manufacturers in a quandary, for it rules that no article must bear the word ‘patent’ unless it is really the subject of a patent specification.

A powerful antiseptic and deodoriser can be made by mixing together carbolic acid and chloride of lime, which, when combined, contains sufficiently active properties to correct fermentation. A weak solution is used as a dressing in some gangrenous affections, as it does not cause irritation. The smell, if objected to, can be disguised by oil of lavender.

Fruit may be preserved in a fresh condition for many months by placing it in very fine sand sufficiently thick to cover it, after it has been well washed and dried and then moistened with brandy. A wooden box is the best receptacle to use, and it should be kept well covered and in a warm place.

According to some French gardeners, vines and other fruit-trees infested with ‘mealy-bug’ should have their bark brushed over with oil in November when the leaves are all off, and again in the spring when vegetation commences. This mode of treatment is usually very successful when it is applied to young and vigorous trees.

At a recent meeting of the Edinburgh Field Naturalists’ Club, a paper was communicated by Mr John Turnbull, Galashiels, locally known as a clever microscopist, in which he explained a new and simple method of obtaining beautiful impressions of the leaves of plants on paper. The materials necessary to take these impressions cost almost nothing. A piece of carbonised paper plays the principal part in the process; but it is of importance to have the carbonised paper fresh, and it should be kept in a damp place, for when the paper dries, the pictures that may be printed from it are not so effective. The leaf or plant to be copied is first of all carefully spread out over the carbonised paper on a table, or, better still, a blotting-pad. Next take a piece of thin tough paper and lay it on the leaf. Then, with the tips of the fingers, rub over the thin paper so as to get the plant thoroughly inked. This done, place the leaf on the paper on which the impression is to be taken. A smooth printing-paper gives the clearest copy. The thin paper is now laid on the plant as before, and the rubbing continued. Of course, care must be taken to keep the plant in position, for if it moves, the impression will be faulty. However, the matter is so very simple that anybody should succeed. Impressions taken in this way have all the delicacy of steel engravings and the faithfulness of photographs. His discovery is likely to come into favour for decorative purposes. The headings of letters on the margins of books might be very tastefully adorned with truly artistic representations of plants. The wood-engraver also will find it will serve his purpose as well as, if not better than, photography. Specimens that have been copied by Mr Turnbull’s system, when examined with the microscope, are found to be perfect, even to the delicate hairs that are scarcely visible on the plant to the naked eye.