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Interesting Particulars Concerning the Magnet: Browning

The action of the magneto-electric machine can be well understood by a beautiful piece of apparatus known as Browning's magnetic exploder, of which we here have a representation. It consists of four powerful steel magnets, with an armature or coil placed between their poles. This armature can be rapidly turned by means of the handle which is seen projecting in front of the machine. With this tiny arrangement--only a few inches in length--the magnetic spark can be sent through miles of wire to explode a distant mine. Supposing that the renowned Guy Fawkes could have had the use of such an apparatus as this, he would not have found it necessary to grope with a lantern among his powder barrels. He would merely have had to connect wires from the machine with an explosive fuse--and then he could have retired a mile or two away--the pressure of a button while turning the handle being quite sufficient to blow Lords and Commons into the air. More than once I have considerably startled an audience by firing small cartridges, previously placed round the lecture hall, by means of Browning's exploder. The machine forms a capital means of demonstrating the old discovery of Faraday, that a magnet can furnish an electric current.

Another wonder due to magnetism is the telephone of Professor Graham Bell. The telephone differs from the telegraph in the fact that it transmits actual speech--not mere signals, as in the latter instrument. It is interesting to glance back at the many systems of communication which have been adopted in past years, and which are now, except under rare conditions, altogether superseded by the use of electricity either in the telegraph or telephone. Perhaps the oldest manner of telegraphing signals from one place to another was by beacon fires, placed in elevated positions, so that they could be seen for many miles. After these came the semaphore, consisting of shutters placed in a frame, these shutters being open and shut for long or short periods, and being made thereby to signify different sentences. (An arrangement such as this has lately been suggested for the use of an army in the field when the weather is too dull to use the heliograph, an instrument which will presently be described.) These semaphores, placed some miles apart on high towers, were first established in France at the close of the last century. Later on, this system was impoved upon in England by the use of a pole, having two arms, like our modern railway signal, but all these plans have been eclipsed by the more expeditious and convenient electric telegraph.

The electric telegraph as well as its great rival, the telephone, require wires to connect them together before communication can be established by their aid. But very often people are placed in such positions that the laying of a wire would be an absolute impossibility. In the late Zulu and Afghan campaigns, for instance, our soldiers were frequently so placed that, although they could make cut each other's positions, they had no means of bridging over the distances which separated them, either by a telegraphic wire or by any other means. In spite of all this, such detached camps were able to communicate with one another, and the agent they employed for the purpose was the sun.

You all know that with a piece of looking-glass you can on a sunshiny day direct a ray of light in nearly any direction you choose, by inclining the glass at the right angle. Naughty boys have sometimes been known to do this on purpose to annoy anybody who may be within aim. But idle and insignificant as the occupation may seem, it has given birth to an instrument called the heliograph, which has been and is likely to be of immense importance to our troops. It consists of a little mirror, so swung upon pivots that it can be readily pointed in any direction. There is a hole at its back made by scraping a little of the silver from its surface. Through this hole the operator can observe whether he is directing his flashes to the right quarter. The flashes so sent are some of them long and some short, and by different combinations of these longs and shorts all the letters of the alphabet can be spelt out by the heliograph. The instrument has been successfully worked over a distance of ninety miles, but of course this was in an exceptionally clear atmosphere. When the sun is absent, the same system of shorts and longs can be worked by means of the shutter frame already spoken of, At nights, lamps are used to give effect to the flashes, and in foggy weather, sound is made to take the place of sight, and the longs and shorts are represented by long and short blasts on a penetrating foghorn.