Some interesting particulars of the voyage of the Danish gunboat Fylla to the arctic regions have been published. This vessel was sent out by the Danish government on an exploring and surveying expedition, which has occupied four months, during which time the coast of Greenland has been explored to a very high latitude. Besides this work, many meteorological observations have been made, whilst dredging and trawling for specimens have been steadily pursued. Amongst the valuables so collected, and which have been divided into sections Botanical, Zoological, and Mineralogical, each under the care of a professor, is a meteoric stone weighing about two thousand pounds. Details of the expedition will be published at Copenhagen.
There are at present two large waterways in Africa upon which the attention of many nations is fixed—namely, the Nile and the river Congo. The interest regarding the first is of a military character, with which these pages have little to do; but with regard to the Congo there is much to claim our attention. Mr H. M. Stanley has recently addressed the London Chamber of Commerce upon the subject, and has given a most interesting account of his personal experiences among the tribes inhabiting the valley of the great river. He describes the natives as being peaceful and anxious to trade with more civilised nations. The International African Association, of which Mr Stanley is a member, was formed some years ago under the auspices of the king of the Belgians, to put down slavery in this region, and to secure a system of free trade for the commerce of the world. Traders of all nations are invited by the Association to bring their goods to the river Congo, which presents, including its affluents, a navigable river of three thousand miles. When cordial relations between traders and natives have been established, the Association will consider the object of its existence to have been gained, and will be dissolved. The sole hindrance to the successful carrying out of the programme seems to be the presence of Portuguese settlers at the mouth of the river, which they claim to have discovered about four hundred years ago. They regard this discovery as an excuse for levying a heavy toll on every vessel ascending the river.
A clever system, by which shafts can be easily sunk in watery soils and quicksands, the invention of Herr Poetsch, was recently described in a paper read before a French Technical Society. The space where the shaft is to be sunk is marked out by a series of hollow iron tubes, which are driven into the ground, and form a ring round the site. In these hollow tubes are introduced smaller tubes, pierced with holes, through which a refrigerating liquid is forced in a continuous current until the ring of tubes is bound together by a wall of ice. By this means, the intrusion of sand and water is prevented while the sinking of the shaft is being accomplished. At a colliery in Prussia, belonging to Messrs Siemens, this plan has been successfully adopted. Indeed, it is difficult to see how the coal, which was overlaid by a quicksand, could have been won by any other means.
A novel method of street-paving has been tried with some success in Berlin; but as its trial only covers twelve months of traffic, it can hardly be held to have proved its superiority over other systems. The material is asphalt, but not treated in the usual manner. Bricks impregnated with the compound, under which treatment they lose their natural brittleness and become elastic, and capable of resisting heavy pressure and damp, are laid in rows just like the wood-blocks used for a similar purpose in this country. The new paving is said to last well and to afford a sure foothold to horses. There is certainly an opening for improvement in our present systems of paving.
Mr Hiram S. Maxim, whose name is well known in connection with a system of electric lighting which was introduced by him a few years back, has invented a machine-gun which has lately been exhibited in London, and which gives some remarkable results. This gun has a single barrel only, which is protected from undue heating by a water-jacket. The cartridges are supplied to it in a continuous canvas belt, not unlike the belt carried by sportsmen. The recoil of the gun at each discharge is utilised in bringing forward the next cartridge, forcing it into position, cocking the hammer and pulling the trigger, so that the gun when once set going is automatic. If its attendant were killed in action, the weapon would in fact go on firing its complement of cartridges until the last one was expended. The rate of discharge can be regulated from once a minute to the astonishing maximum of six hundred per minute. The same system of belt-feeding has been applied by Mr Maxim to ordinary rifles fired from the shoulder; and it is probable that the attention of our War authorities will be called to the matter.
How few of us realise the fact that there are among the sixty-three hitherto known elements of which this world is composed, no fewer than fifty metals. A large number of these are so rare that they cannot be said to have much importance; but frequently the so-called rare metals are, as knowledge advances, stepping over the boundary-line which separates them from metals having a commercial value. Of these, aluminium and magnesium hold a foremost place. But now another metal, iridium, often found associated with platinum and gold, is coming into use. (Possession of or dealing with iridium has hitherto been forbidden by Russian law, because it was found that gold was adulterated with it. When gold so treated was afterwards worked at the Mint, the individual particles of iridium indented the rollers, played havoc with the machinery generally, and entailed great loss on the government.) It was discovered a few years ago that this hard and intractable metal can be readily fused by the addition of phosphorus, the resulting material retaining all the hardness of the original metal. Hitherto, iridium has been used almost solely for pen-points. There are now, however, many uses found for it, among which we may mention draw-plates for wire, the wearing parts of various philosophical instruments, and contact-points for telegraphic apparatus.
An improvement in the art of glass-blowing has been introduced at the works of Messrs Appert, at Clichy, of which it may be said that it is remarkable that it was not adopted many years ago. Glass-blowers are by reason of their occupation subject to various diseases of the lips and cheeks, while the hot atmosphere in which they are compelled to work renders their frames peculiarly liable to other disorders. Instead of using the breath from the lungs to distend the bubble of molten glass, Messrs Appert have adopted the method of storing air under pressure for that purpose. The results are satisfactory in every way. The workman’s health is greatly improved, and so is the quality of his work, while the rapidity of production is naturally much increased.
The prorogation of parliament means not only the release from work of the members thereof, but is also a welcome relief to that class of newspaper readers who care little for acrimonious debate. During the recess, space is found for much interesting matter that would otherwise be lost, and those with hobbies, useful and otherwise, have opportunity for airing their knowledge and their grievances. For instance, we usually find in the newspapers many interesting letters on natural history; and the doings of particular birds, beasts, and fishes form the subject of much curious correspondence. The old question whether the ubiquitous sparrow is the friend or foe of the farmer has once more been raised. The evidence on this point is very conflicting, and leads one to assume that the sparrow is mischievous or useful according to local circumstances. One correspondent calls to mind a curious collection of the contents of the crops of various birds which was shown by a Frenchman at the Great Exhibition of 1851. This exhibit clearly showed that the bulk of the food was insectivorous, the grain being a minimum. On the other side of the discussion, we may refer to a paper lately read at a Farmers’ Club in Chester in which it was alleged that sparrows’ crops had been found with an alarming amount of wheat in them, and operations for reducing the numbers of the feathered pilferers were advocated. Still, the evil may be counterbalanced by the good.
It has lately been proved by direct experiment at Marseilles that the lower animals can be inoculated with the virus of cholera obtained from a human patient, and that death ensues with the same symptoms as are exhibited by mankind. It is believed that this fact will offer a sure method of diagnosing a case of true cholera, a guinea-pig or a dog serving as a necessary victim. Another curious observation has been made respecting this dread disease. The gastric juice and the bile tend to act as destroyers of the microbes. These secretions are most abundantly brought to bear during a meal, but hardly at all when liquid nourishment alone is taken into the stomach. It would therefore appear that there is much less risk in drinking contaminated water with food, than if it were merely taken alone to quench the thirst.
Mr James M. Share, R.N., sends us from South Africa a description of a leak-stopper which he has invented, and which, from its simplicity and cheapness, should command the attention of shipowners. It is founded on the old system of hanging a sail over a ship’s side to stop the inrush of water when from a collision or other cause a ship’s side suffers injury. Mr Share’s stopper consists of a strong canvas sheet rolled up upon an iron stove-pipe. By suitable gearing, the contrivance can be dropped overboard in any required place, when the sheet unrolls and covers the leaky place. It will therefore be seen that the invention aims at doing in a ready and workman-like manner that which has been done in haphazard fashion from time immemorial. We have particular pleasure in calling attention to this invention from the circumstance that its contriver does not intend to patent it, but offers it freely as a useful contribution to the means of saving life at sea.