Device to Locate Aeroplanes

 RHODESIAN´S REMARKABLE INVENTION

Device to Locate Aeroplanes

 Prevention of Raids

 Among the many excellent men who left Rhodesia to take part in the Great War, the name of Mr. J. M. Moubray, who held a commission in the Royal Engineers, will hold a prominent place, and indeed is today associated with one of the most remarkable inventions of the war.

 Mr. Moubray, it may be explained, has been in Rhodesia for over 18 years. A mining engineer by profession, he was at one time manager of the Bernheim mine, Mazoe, and afterwards was Assistant Engineer for the Northern Copper Co. Presently he is engaged in farming and other operations in the Shamva district.

 We believe it will be a distinct pleasure to all Rhodesians to learn of the services he has rendered to the Empire by reason not only of his excellent work in France, but also in connection with the invention known as the “listening well” method of locating aeroplanes in flight in the dark. The achievement reflects not only honour upon Mr. Moubray, but also upon this country, and its effects are not to be estimated at the moment.

 

Early Days in France

 Mr. Moubray went overseas from Rhodesia early in 1916 and, on account of his technical knowledge, was sent straight to France, receving his commission in the Royal Engeneeiers as a member of the tunneling section. During his early service, Mr Moubray was before Ypres for twelve months. There he had the misfortune to be hit by a shell, and whilst lying unconscious he was gassed. As a resn´t of his injuries he was sent home, and upon his recovery he acted as instructor at the Royal School of Mines, giving the cadets the benefits of his wide knowledge in tunneling matters of which, by the way Mr Moubray had many interesting and fascinating experiences to relate. It was during his associating to the Royal School, of Mines that he first developed his idea, which was to lead to a revolution of method to combat by aircraft. (the rest is illegible)

 

Inventions the idea was not sympathetically received at the time, but its innate merit was destined to force itself upon the attention of the War office. Eventually, practical demonstrations were made in London in the autumn of 1917, and subsequently four stations were established in London. Later Mr. Moubray was sent to France again to install his apparatus, which he did before Peronne. He had scarcely settled down to work when the Bosche came over on March 21, 1918, and in order to prevent the capture of this valuable instrument it was destroyed. Following upon this Mr. Moubray was again sent home, where he reorganised his scheme, but he was back again at Amiens about July. Again he had hardly had time to demonstrate the capabilities of the instrument when our offensive started in August, and with the rapid advance of our armies the practical utility of the machine was not fully taken advantage of. This necessitated another visit to England, where an experimental station was established at the big aerodrome at Hendon. After several demonstrations the instrument was inspected by the powers and pronounced a huge success. Indeed so important was the discovery thought to be that a special department at Woolwich was set up under Major Tucker, whose name will be remembered with gratitude on account of his wonderful invention, the Tucker microphone. By a stroke of genius Major Tucker successfully applied the microphone to the listening well, and the result is that to-day the combined apparatus is capable of almost untold possibilities. Moreover the new acoustical research department at Woolwhich is at the moment busily engaged in developing the instrument and putting experiments into practical effect.

 The Invention

We anticipate our readers remark, “what is this wonderful invention?” we make no pretence at a technical description. Briefly the apparatus consists of several listening stations arranged at fixed distances apart. These stations ascertain, to the minutest degree of accuracy, the altitude of the plane, its travelling velocity with regard to the earth, and its direction of flight. (the last part was burnt so this is a deduction)

 Each station is situated about 2,500 yards apart, so that having discovered the above essentials, it is pure mathematics to calculate how long the plane will take to cover a distance and enter another cone of sound. Having these facts, it is apparent it can be easily calculated at what precise moment the plane will occupy a given place in space. Information can then be communicated to the guns defending aircraft or searchlights, with the result that the guns can be trained upon the exact place which the plane is to pass and can be fired at the exact moment the machine reaches the spot destined for its destruction, or the defending aircraft can be directed to the spot to attack in the dark when the target is illuminated at a given moment. This of course completely does away with the necessity for a general barrage over a town and its environs, as was the case when bombing machines raided parts of England and elsewhere. One can well imagine the tremendous importance of such an invention, and regret that it was not applied during the earlier stages of the war. It must have averted great loss of life, huge damage to property, and incidentally avoided the lavish expenditure of ammunition entailed in general barrage. (the rest is burnt and illegible)

 

What of the future?

 As the result of further research the potentialities of the discovery become more apparent and vital daily. Just as the instrument records the most minute sound vibrations in the air within the cone, so conversely it is now possible to project sound into the cone from the earth.

 The tremendous importance of this will be seen by a simple illustration. Fog is the enemy of the airman. Well we will suppose that an airman is befogged and is searching for his aerodrome or landing place. A properly attuned note can be sent from earth and received on an instrument with which the aeroplane is fitted. Guided by this, the airman can effect a landing in safety at night time or in the densest fog. How many lives would have been saved and accidents averted had this almost uncanny instrument been put into practical use during the war? The reader can be left to his own imagination!

 As indicating the marvellous precision of the instrument, it may also be mentioned that the observer is in a position to know what type of aeroplane is passing within the sound cone by virtue of the frequency of the vibrations peculiar to the several types. Thus for instance, knowing the machines adopted by the enemy—without actually seeing the plane—it would be possible to direct the gunners to open fire as previously mentioned without running the risk of bringing down one of our own aircraft. As we have said before the combination of this instrument with the microphone has added a remarkable device to our aerial defences and has done much to give to Great Britain the right to the proud title of mistress of the air as well as of the seas. Rhodesians will feel a glow of pride at the fact that in winning this place the Old Country owes a deep debt of gratitude to a gentleman and a Rhodesian of such pre-eminent talent and ability as Mr. Moubray. We feel it is a privilege to be in a position to give even his inadequate description of this wonderful invention, and believe that the country would give a correct measure of credit to the gentleman to whom it is full due.