APPLICATION OF ELECTRO-MAGNETIC POWER TO RAILWAY TRANSIT.
One of the most wonderful characteristics of scientific discovery is the singular way in which every advance connects itself with past phases of progress. Each new victory over the stubborn properties of matter not only gives man increase of power on its own account, but also reacts on older conquests, and makes them more productive. Thirty years ago, Davy and Arago observed that iron-filings became magnetic when lying near a wire that was carrying a current of galvanic electricity. Since then powerful temporary magnets have been made for various purposes by surrounding bars of soft iron by coils of copper-wire, and transmitting electric currents through these. In fact, it has been ascertained that iron always becomes a magnet when electricity is passed round it. The alarm-bells of the electric telegraphs are set ringing by a simple application of this principle. A conducting wire is made to run for hundreds of miles, and then coils itself round an iron bar. Electric currents are sent at will through the hundreds of miles of wire, and the inert iron becomes an active magnet. Observe the clerk in the Telegraph Office at London. When he jerks the handle that is before him, he turns on a stream of electricity that runs to Liverpool or Edinburgh, as the case may be. In either of those places a piece of iron that is twisted round with the extremity of the wire becomes a magnet for an instant, and attracts to itself a steel armature that is connected with a train of wheel-work. The motion of the armature, as it is drawn up to the magnet, sets free a spring that was before kept quiet; and this gives token of its freedom by making an alarm-bell to ring. The clerk in London awakens the attention of the clerk in Edinburgh by turning a piece of soft iron placed near to the latter into a magnet for a few seconds. He is able to do this because currents of electricity induce magnetism in iron. This, and this alone, is the secret principle to which he is indebted for the wonderful power that enables him to annihilate space when he instantaneously attracts the attention of an ear hundreds of miles away.
It has recently been announced that this electro-magnetic induction has been made a means for the instantaneous registration of astronomical observations. We have already to draw attention to another practical application of the principle. M. Niklès has just invented an arrangement of apparatus that enables him to make the wheels of locomotives bite the rails with any degree of force without increasing the weight that has to be carried to the extent of a single grain. Our readers are aware that in wet weather the driving-wheels of locomotives often slip round upon the rail without acquiring the power of moving the weight that is attached behind them. Whenever they are asked to ascend inclined planes with a weight that is beyond the adhesive powers of their wheels this result invariably follows; and the only practical escape from the difficulty hitherto has been the adoption of one of two expedients—either to increase their own intrinsic weight, so that the earth's attraction might bind the wheels down more firmly, or to let the railway be level and the load to be dragged proportionally light. In either of these cases a waste of power is experienced. Power is either expended in moving a superfluous load, or the same amount of power drags less weight even upon a level rail than it otherwise could upon an ascending one, that would have required less outlay in its construction. It therefore becomes a great desideratum to find some means of making the locomotive wheels bite more tenaciously without increasing the load they have to carry. The important problem of how to do this it is that M. Niklès has solved.
If our readers will take a common horse-shoe magnet, and slide the connecting slip of steel that rests upon its ends backward and forward, they will feel that the slip sticks to the magnet with a certain degree of force. M. Niklès' plan is to convert the wheel of the locomotive into a magnet, and make it stick to the iron rail by a like adhesion. This he does by placing a galvanic battery under the body of the engine. A wire coming from the poles of this battery is then coiled horizontally round the lower part of the wheel, close to the rail, but in such a way that the wheel turns round freely within it, fresh portions of its circumference coming continually into relation with the coil. The part of the wheel in immediate contact with the rail is thus made magnetic, and therefore has a strong adhesion for the surface along which it moves—and the amount of the adhesion may be increased or diminished at any time, by merely augmenting or reducing the intensity of the galvanic current that circulates through the surrounding coil. By means of a handle the electricity may be turned on or off, and an effectual break be thus brought into activity that can make the iron rail smooth or adhesive according to the requirements of the instant, and this without in any way interfering with the free rotation of the wheels as the friction-breaks of necessity do. Increased adhesion is effected by augmented pressure, but the pressure results from an attraction that is altogether independent of weight. The lower portion of the wheel for the time being is in exactly the same condition as a bar of soft iron placed within a coil of wire circulating electricity. But as it rises up out of the coil during the rotation of the wheel, it grows less and less magnetic, the descending portions of the opposite side of the circumference acquiring increased magnetic power in the like degree.
M. Niklès' experiments have been made with large locomotives in full operation; and he states as the result, that the velocity of the wheel's motion does not in any way affect the development of the magnetic force. He finds the condition of the rail, as regards wetness or dryness, to be quite unimportant to the success of his apparatus, and he has already managed by its aid to achieve an ascent as rapid as one in five.
THE STOLEN ROSE.
Geraldine Delisle was the year previous to the late Revolution, which in one day shattered one of the great monarchies of the earth, the reigning belle in her circle. Lovely in form and face, she wanted but to correct some trifling defects of character to be perfect. But if she had large black eyes and massive brow, and beautiful hair and white teeth—if she had a lily-white hand and tiny feet, she knew it too well, and knew the power of her charms over man. She loved admiration, and never was so happy as when in a ball-room all the men were almost disputing for the honor of her hand. But Geraldine had no declared suitor; she never gave the slightest encouragement to any one. Many offered themselves, but they were invariably rejected, until at twenty her parents began to be alarmed at the prospect of her never marrying. M. and Mme Delisle had found so much genuine happiness in marriage—the only natural state for adult human beings—that they had promoted the early marriage of two sons and an elder daughter; and now that Geraldine alone remained, they earnestly desired to see her well and happily married before they died. They received numerous offers: but the young girl had such winning ways with her parents, that when she declared that she did not like the proposer, they never had courage to insist.
During the season of 1847 Geraldine never missed a party or ball. She never tired as long as there was music to listen to, and it was generally very nearly morning before she gained her home. About the middle of the season she was sitting by her mother's side in the splendid salons of the Princess Menzikoff. She had been dancing, and her late partner was saying a few words, to which she scarcely made any reply. Her eyes were fixed upon a gentleman, who, after observing her for some time, had turned away in search of some one. He was the handsomest man she had ever seen in her life, and she was curious to know who he was. A little above the middle height, slight, pale, with great eyes, soft in repose like those of a woman, he had at once interested Geraldine, who, like most women, could excuse every bad feature in a man save insipid or unmeaning eyes; and she asked her mother who he was.