LIGHTING SHIPS BY ELECTRICITY.-Mr. H. Wilde, of Manchester, has succeeded in lighting a ship by electricity, with results that seem to settle the question as regards practicability and completeness of effect. Any one who has been on board a vessel of war knows how dark and dismal, notwithstanding oil-lamps, the lower decks are henceforth they will be as bright as day, and even brighter in gloomy weather, for Mr. Wilde can now divide the working-current without difficulty, and introduce as many points of light as may be necessary. Instead of pairs of carbons separated by plaster of Paris, he coats the carbon separately with a film of hydrate of lime, and mounts them in couples in such a way that when the current is passing they stand at the proper distance apart for producing a perfect light. An experiment made on board the Inflexible may be taken as the commencement of a change which will very greatly mitigate the discomfort of life in an iron-clad. Four of Mr. Wilde's improved lamps were placed in one of the engine-rooms, and, according to the official Report, "when lighted up, the effect was most startling the opal shades gave off so powerful and brilliant an illumination that the engine-room, which is considerably below the water-line, appeared to be filled with daylight, and the moving parts of the engine were rendered visible.' Apart from the abundant light, there is the advantage that neither heat nor smoke is generated—a very important consideration, within the narrow limits of a ship; and it is not surprising that the Lords of the Admiralty, in whose presence the experiment " was made, were warm in their expressions of surprise and gratification." THE BLACK MILDEW OF WALLS.-In Science Gossip for August, 1878, there was an article by Professor Paley, entitled "Is the Blackness on St. Paul's merely the Effect of Smoke?" in which the author maintained that this blackness is chiefly due to the growth of an undescribed lichen, which appears to flourish only on limestone and in situations unaffected by the direct rays of the sun. Professor Leidy, calling the attention of the Academy of Natural Sciences of Philadelphia to this paper, remarked that he had himself, many years ago, noted a similar black appearance on the brick walls and granite work of houses in narrow shaded streets, especially near the Delaware River. Noticing a similar blackness on the bricks above the windows of a brewery, from which there was a constant escape of watery vapor, he was led to suspect that it was of vegetable nature. On examination it proved to be caused by an Alga, closely allied to what he regarded as Protococcus viridis, which gives the bright green color to the trunks of trees, fences, and walls, usually on the shady side. It may be the same plant in a different state, but until this is proved he proposes to name it Protococcus lugubris. It consists of minute round or oval cells, from 0.006 to 0.009 millim. in diameter, isolated, or in pairs or groups of four, the result of division, or, in short, irregular chains of from four to a dozen, sometimes with a lateral offshoot of two or more cells. THE ORIGIN OF OUR DOMESTIC ANIMALS. -Palæolithic man, who existed for so long a period in Western Europe during the quaternary age, was probably autochthonous. But at the commencement of the neolithic age, a new civilization was suddenly introduced, and a new type of man appears on the scene. Neolithic man, with his polished stone implements, brings with him a number of domestic animals-the dog, the goat, the sheep, the ox, the horse, and the pig. By studying the origin of these animals, and determining their ancestral home, light may obviously be thrown upon the source whence the neoliths migrated. Such a study has been undertaken by Professor Gabriel de Mortillet, who has contributed an interesting paper on this subject to the current number of M. Cartailhac's Matériaux pour l'Histoire de l'Homme. Neolithic man, according to Mortillet, came from Asia Minor, from Armenia, and the Caucasus. These, in fact, are said to be the only countries which could have and cereals which the neoliths brought with yielded the assemblage of domestic animals them upon their invasion of South-Western Europe during the Robenhausen period. BLASTING COAL BY COMPRESSED AIR.-At a meeting of the Manchester Geological Society, Mr. W. E. Garforth gave an account of a method of blasting coal in mines by means of compressed air, whereby the risk attending the use of gunpowder is obviated. With a portable machine of simple construction, which can be worked by two men, he gets a pressure of more than fourteen thousand pounds to the square inch. The cartridge, an iron tube, is drilled into the coal; the pipe from the compressor is connected, the air is forced in, and, in the experiments hitherto made, the cartridge bursts, and the coal falls before a pressure of ten thousand pounds to the inch is reached. When coal is brought down by firing a charge of gunpowder, half an hour or more is wasted while the smoke drifts away from the working, before the miners can resume their labor; whereas the sudden expansion of the compressed air may be regarded as beneficial. To obviate the objection that the labor of working the compressor in the heated air of a mine would be exhausting, Mr. Garforth proposes to fill receivers with compressed air above ground, or at the foot of the shaft, then transport them to the several workings, and there burst the cartridges by liberating the imprisoned air. It is said that this method is more expensive than blasting by gunpowder; but there is much in its favor; and considering the appalling loss of life of late years in coal mines, the Government Commission appointed last session to inquire into the subject will in all probability recommend that the use of gunpowder should be forbidden. HARDENED GLASS.-M. de Luynes has recently communicated to the French Society of Encouragement, in the name of M. de Labastie, further information on the progress which the industry in hardened or tempered glass has recently been making. He showed to the meeting numerous specimens, which presented the most varied and accurate forms. There were tubes for lamps, both gas and oil, goblets of various forms, mortars and pestles, etc. As to the latter, M. de Luynes reminded the society how frequently accidents happened with them; the least fall breaks them, whereas with hardened glass they stand any amount of hard usage. He also showed capsules for pharmacy and chemistry, of all sizes and shapes, plates of glass, crystal, and enamel, coffee and tea cups in white enamel. He finished by making a striking experiment. Ordinary glasses were placed in a basket with drinking glasses of the same shape in hardened glass; after several shakings the ordinary glasses were all broken, while all the hardened glasses were intact. Thus it would seem that all the difficulties of the question have been solved. But, what is more important, the processes of manufacture have been simplified and combined with the ordinary operations of glass-blowing, so as considerably to diminish the expense and give more regular forms and more perfect execution. Objects made with the liquid material, when they are still red, are thrown directly into the tempering bath, and are not again heated to the melting point, as at first, which often causes a change in their form. Bottles, drinking glasses, lamp glasses, and other concave objects containing air are received on a curved tube, a sort of siphon, which at the moment of immersion allows the air to escape, while the liquid enters the cavity without difficulty. All these improvements have been adopted at the glassworks of Choisy-le-Roi, and it is confidently expected that in a very short time objects in hardened glass will be quite as cheap as those made in the ordinary way. FIRE-PROOF COMPOSITIONS.-Various combinations of ammonia and borax have been suggested in Paris for rendering textile fabrics inflammable. Here is one applicable to all kinds of goods: Sulphate of ammonia (pure), January, 8 kilos; carbonate of ammonia, 2.5 kilos; boracic acid, 3 kilos; borax (pure), 1.7 kilos ; starch, 7 kilos; water, 100 kilos. It is simply necessary to steep the fabrics in a hot solution composed as above until they have become thoroughly impregnated, after which they are drained and dried sufficiently to enable them to be ironed or pressed like ordinary starched goods. A second composition to be used for theatrical scenery (or the mounted but unpainted canvas to be used for this purpose), and also for woodwork, furniture, door and window frames, etc., is to be applied hot with a brush like ordinary paint. It is composed of boracic acid, 5 kilos; hydrochlorate of ammonia or sal ammoniac, 15 kilos; potassic feldspar, 5 kilos; gelatine, 1.5 kilos; size, 50 kilos; water, 100 kilos; to which is added a sufficient quantity of a suitable calcareous substance to give the composition sufficient body or consistency. Another composition, applicable to all kinds of paper, whether printed or not, including securities, books, etc., is formed of sulphate of ammonia (pure), 8 kilos; boracic acid, 3 kilos; borax, 1.7 kilos; water, 100 kilos. The solution is heated to 122° Fahrenheit. If the paper be in sheets or printed, it is simply immersed in the solution, spread out to dry, and afterward pressed to restore the glaze destroyed by the moisture. The above compositions insure a high degree of incombustibility. The proportions of the several ingredients are given as examples only, and may be varied as found necessary in practice. VARIETIES. CHRISTIAN AND PAGAN ROME.-Christians, in the early stages of their intercourse with a world still pagan to its very core, were withdrawn from the feelings and associations of the common life with which, externally, they were in contact. Shut out in a great degree from public affairs; debarred from the courts of law, excluded from many of the ordinary amuseor, at least, infrequent in their attendance; ments and popular festivities, most of which were tainted with idolatry, or with the moral corruptions which underlay it-the primitive Christians, by a happy necessity, were long life with the new conditions which it involved; thrown back upon each other and upon a family and although afterward, when paganism lost its hold upon the world, and when the new religion succeeded to the social, as well as the civil and political, privileges of the old one, the Christian returned to his place in public life, and to the duties and relations which are connected with it, the better tone at once introduced continued to maintain its ground, and established a higher law of life and morals, which has never since been entirely lost. It must not be supposed, however, that in the midst of the early fervor of primitive profession the amenities, and even the frivolities, of life entirely disappear from the picture. There is a curious evidence of this in the miscellaneous objects which have been discovered in the catacombs, and to which, in the absence of written records, we have to look for light on the habits of life that prevailed among the Christian population of Rome; and the Christian community of Rome may be taken as including some elements, at least, of almost every contemporaneous people and race to whom the Gospel had been made known. The objects of use in every-day life found in the Christian cemeteries resemble in most particulars the ordinary pagan remains of the same class. We further find some direct evidences of the pursuit among Christians of the lighter occupations and amusements. Then, as now, Christian children had their toys and playthings. Jointed dolls of ivory or bone, bronze or terracotta mice, glass fishes, etc., are found in the little loculi, whose dimensions, and occasionally inscriptions, touchingly bespeak the tender age of the departed, as though the parent had found a melancholy consolation in hiding away along with the dear deceased the ornaments or playthings which had lost their use in the death of the possessor. Masks have been occasionally discovered; but it may be doubted whether they were intended for use in scenic representations. Dice, too, although but rarely, appear, as though games of chance were not altogether without their votaries; nor were Christian ladies entirely so spiritual as to refuse the use of mirrors and the other appliances of the toilet-combs, tweezers, pins, bodkins, toothpicks and earpicks, vinaigrettes, etc. Ornaments, as well as objects of necessary usebuttons, buckles, and bullæ, bracelets, armlets, necklaces, rings, and ear-rings-are still to be seen in the Christian Museum of the Vatican. Even the little vanity of false hair was not unknown among the ladies of Christian Rome. Boldetti mentions that in not a few instances it is found in the tombs. It is more pleasing to discover those pledges of family affection which we ourselves love to preserve; and although there are many more solemn and more sacred memorials of these primitive times, we know none more touching than a little object in ivory--an egg engraved with companion portraits of a husband and wife, and marked with the Christian monogram. In these and many similar indications we are brought into contact with one of the lighter aspects of the domestic life of the little Christian community, mixed up as it was with the pagan world of Rome. -Edinburgh Review. HEDGEHOG AND VIPER.-The common hedgehog is generally described as a mortal enemy to snakes of all kinds, and it has been supposed that he enjoys an immunity from the effects of the bites of the venomous species. M. Samie with a circumstantiality which reminds one of the reports of prize-fights in Bell's Life during the palmy days of the ring, relates all the particulars of a combat which he excited between a hedgehog and a viper (Vipera aspis). The hedgehog attacked the snake as soon as he was aware of its presence, seizing it in the first place at the hinder part of the body, and continuing his assaults until his formidable enemy was reduced to a helpless state, when he com. menced eating it at the tail end; afterward,. proceeding to the head, he carefully detached and devoured the lower jaw. The viper was still alive. The most interesting point brought out by this experiment of M. Samie's is the mode in which the hedgehog defended himself against the dangerous weapons possessed by his adversary. When bitten, the viper at first turned to strike its assailant, when the hedgehog immediately drew forward over his head that mass of spines which forms the front part of his defences; and when the snake struck open-mouthed at its persecutor, its attack was foiled by this formidable cheval-de-frise. Several times the same manoeuvre was repeated, until the snake's mouth was so severely lacerated that it no longer attempted to use its fangs, but sought safety in vain in flight. The hedgehog frequently rolled himself up for a time after having made an attack upon his victim. M. Samie's results are interesting, but it is clear that he has not the fear of antivivisectionists before his eyes.-Actes Soc. Linn. de Bordeaux, 1873, p. 257. EARLY DAYS OF VICTOR HUGO.-Victor Hugo was born in 1802, and in his parentage we find a twofold influence which has affected his character: from his father, who was a General of the Republic, and an ardent admirer of Napoleon, he drew his Democracy and his hero. worship; from his mother, the daughter of a ship-builder at Nantes, the Royalist fervor of his early opinions, the devotion to throne and legitimacy which produced "Louis XVII." and “Le Sacre de Charles X." His first years were years of wandering, as the exigencies of the service demanded. General Hugo and his family removed from Besançon to Marseilles, from Marseilles to Paris, and thence into Italy, where the young imagination of the little Victor was nourished in the very land of poetry and of beauty. His earliest recollections were of the "silver sparkle" of the Adriatic, the Bridge of St. Angelo, with its imposing statues, and Naples, glistening in the sunshine, fringed with azure sea. General Hugo was appointed Governor of Arellino, but before long was summoned to Spain by King Joseph, and the children were sent with their mother to Paris for education. They were lodged in the ancient convent of the Feuillantines, whose chestnut alleys and tangled vines were the delight of the three boys. Victor showed a great aptitude for study. At nine years old he taught himself Spanish in a few weeks, with the help only of grammar and dictionary, and spoke it passably, only hesitating as to the pronunciation. The family of General Hugo joined him at Madrid in 1811, and already the feeling for architecture which afterward so strongly distinguished the man was taking root in the mind of the boy; a deep impression was made upon him by the towers of Angoulême, which he drew long after from that early memory of travel. The boy was placed with his brother at the College of Nobles; the Spanish solemnity, the rigid monastic severity, of this institution, where the French children were naturally looked upon as intruders, chafed their expansive natures; and it was with joy they prepared to follow their mother back to Paris. The affairs of Napoleon were going ill in Spain; General Hugo judged it prudent to place his family in safety. The restoration of the Bourbons found them once more at Les Feuillantines, where they were joined by the General, now deprived of his command, and occupying himself with the future of his children. During these school-days at Paris it was that Victor Hugo essayed his first verses. A chivalrous and dreamy character stamps them; the child repeated in his lines the beliefs of the mother; her passionate love for royalty and hatred of the revolution breathe in these early and faltering stanzas. The Academy would have crowned his poem on "The Happiness Afforded by Study" had they not considered it impossible such verses could have been written by a lad of fifteen. His earliest prose work, Bug Jargal," also dates from this age, and was written in a fortnight, as the fulfilment of a wager among some young students of the College Louis-le-Grand.-Biograph. PROTECTIVE MIMICRY IN BIRDS.-Birds offer a few undoubted cases of mimicry, the most perfect being that of some species of Mimeta, a genus of brown orioles, which mimic Philedon, a genus of honeysuckers. The latter birds, it may be remarked, are the largest of their family, and are very noisy and pugnacious; they are also very plentiful, and will band together to drive away crows and even hawks that intrude among them. We may presume, therefore, that they are generally unmolested, and it would thus be of use to any weaker bird to be mistaken for them. The orioles, though nearly as large, are decidedly weaker birds, and are far less numerous, and thus correspond to the general character of mimicking species. In the island of Bouru, one of the Moluccas, there is a peculiar species of Philedon (P. bouruensis), and in the same island a peculiar species of Mimeta (M. bouruensis), which are so much alike that in a great French work, the "Voyage de l'Astrolabe," the oriole is figured and described as a honeysucker under the name of Philedon bouruensis! the two birds belonging to families at least as distinct as thrushes and crows. The manner in which the imitation is effected is very curious. The Philedon bouruensis, as in almost all the species of the genus, has a large bare patch of black skin round the eyes; this is copied in the Mimeta bouruensis by a patch of black feathers. The narrow scale-like feathers on the crown of the Philedon are imitated by a dark line on the broader feathers of the Mimeta. On the neck of the Philedon the feathers are recurved, showing their pale under-surfaces and forming a kind of ruff or cowl which has given to them the name of friar-birds, and this is represented by a pale band in the Mimeta; and lastly, the bill of the Philedon has a protuberant keel at the base, and the Mimeta has the same character, though it is not found in the allied species. The colors of this pair of birds are simply brown, darker above and lighter below; but in the adjacent island of Ceram there is another species, Philedon subcornutus, which has a great deal of ochre-yellow in its plumage, and this is exactly imitated by the corresponding Mimeta forsteni, both being confined to this single island. If it could be thought that the resemblance in the one case might be accidental, and that their occurring in the same island was also a coincidence, the occurrence of another pair in another island renders this explanation inadmissible; but to any one who has comprehended the general principles of mimicry, it will be clear that these are of exactly the same nature in the case of these birds, and can be explained only in the same way. — Science for All. RONDEAU. A ROSE fell from her hair last night, A rose. THEO. MARZIALS. |