The Direction of Aerial Highways.

Kaipara and Waitemata Echo, 6 November 1914, Page 2

The Direction of Aerial Highways.

Amongst the eastern tales which M. Antoine Galland brought from i'onstantinople about two hundred years ago, there was one about a mountain of lodestone, which destroyed ships by attracting and drawing out all the iron nails. This was before the days" of manufactured electricity and of electromagnets, and no one knew of the existence of magnetic waves which might be used to transmit signals, and help vessels instead of injuring them, but it did include the germ of a truth which has only begun to he appreciated, and even as yet but little utilised. To-day the influence of magnetism supplies not only the magnetic needle, by which a guide for direction is provided, but it ' also enables shore stations to send out time signals, checking r.he chronometer, and insuring cor-, rect determination of longitude.

It is possible, says a writer in the " Scientific American," that there may yet be developed such a

rontrol of niegnetic lines of force is will enable air routes to be di-

rected in a manner even more definite than the lanes in which transatlantic steamers are operated.

One of the greatest difficulties which appears in the way of longdistance aerial journeys, assuming the practicability of continuous Mi^ht, is that of maintaining the deHiiod direction, in the midst of flouds and fog, and in the darkness i-.i' the night. The vibration of the machine and the difficulty of taking observations of position, even in clear weather, render it most •.it'birable that some positive and direct guidance be furnished, not limiting the machine to such a close line as to involve possible collision with others, but indicating definitely the route along which progress should be made.

Hertz has indicated the practicability of directing magnetic waves, and Tesla has proposed definite trains of electrical waves, and it seems as if further work along these li'ies might result in the de\elopment of a method of indicating air routes, independently of any observations of the compass or of celestial bodies. The existence of a definite train of waves through space, say from New York to London, which would immediately indicate to the airman the fact that he was in the right road, probably by the response of a sensitive detector, would permit him to dispense with any other effort to direct his machine except to keep it \vithin the path of magnetic effect, iml to watch for any material dei iation from the path. Such a method would be wholly apart from tny attempt to transmit energy by means of waves ; that is, sufficient energy to be capable of use as propelling power, but it would enable Lhe response of the detector to assure the navigator that he was proceeding in tho dityuV path to his destination, in whichever direction he might be headed.

]t is not improbable that the successful introduction of such directive regions would later lead to the supply of motive power through space, and thus remove one of the chief practical difficulties to longdistance aerial travel, the limitations of fuel supply. Each development in such work leads on to the next, and the surest way to attain such a result as a stream of directed radiant energy over a determined rente would seem to be the provision, at first, of a guiding line, which might later become

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