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Aviation History
1915
1915 - 0304.PDF
THE HASLER APRIL 30, 1915. REVOLUTION. CIRCUMFERENCE AND CUTTING SPEEDS INDICATOR. THOSK whrwe duty it i» to test the *peed of engines occasionally will be interested in the instrument, teen in the photograph, which is being introduced by the Hasler Telegraph Works, of 26, Victoria Street, Westminster, S.W. By the old method it was necessary to hold the watch in one hand and the revolution counter in the otbc r, and if the latter was not applied for a full minute there was a certain amount of calculating to be done. With the Hasler instrument, however, it is all done automatically in one operation, and the time taken is only five seconds. The actual period over which the speed is taken can be absolutely determined, as the instrument does not operate until the knob at the top is pressed, when clockwork, in the interior of the mechanism, engages the indicating mechanism, so starting the instrument, and releasing it after three seconds. During this period the indicating mechanism is in direct Communication with the driving shaft of the instrument, so that an exact record of the speed is provided in a shorter unit of time than would lie possible with tachometers based on the centrifugal or magnetic principle. To use the instrument the pointers are set to xero by means of the button at the back, the friction point placed in the countersunk hole in the moving shaft and, when the speed is rcquiud to be taken, the knob at the top of the dial pressed, the speed then being recorded on the dial as soon as the clockwork stops. The large dial indicates up to 1,000r.p.m., while the smaller dial enables speeds up to 10,000 r. p.m. to be taken. In addition to the faction jxiint which forms an integral part of the instrument, two removable " points" are provided for use where a countersunk hole is not available, for instance. There is also a friction disc by the aid of which it is possible to ascertain quickly and accurately circumference and cutting speeds of any rotating disc. Other important features of the instrument are :— It is anti-magnetic it has an uniform dial graduation, on which any number of revolutions up to 10,000 can be read with equal ® ® MODERN ; the driving shaft can be rotated in either direction ; the accuracy of the instrument is independent of the variable stresses of the springs or friction of the bearings ; it is not affected by vibration or change in temperature ; it can be pressed on the moving body firmly without affecting the time element; the pointers remain on the figures arrived at until re-set. It is well made and beautifully finished, and is priced at £6 in a velvet-lined case. ® © WARFARE-A DISCUSSION. WHAT IS THE MOST TllKKK was a time, and not so very long ago, when the attitude of the general public towards matters aeronautical was tending to be one of • shoulder-shrugging character, due chiefly to a narrow and limited knowledge of the subject. The air work which is being put in daily by aircraft in the great war is, however, rapidly opening the eyes of the public to the usefulness—nay, even vital necessity, of the fifth arm. That the former apathetic attitude is now fortunately changing into one of keen and intelligent interest was very evident from • debate which took place on Wednesday of last week, at a meeting of the Union Society of London in the Inner Temple Lecture Rooms, King's liench Walk. The subject of the motion was " That Aeroplanes and Seaplanes have shown themselves to be the most useful factor in modern warfare, and 'gasbags'the most useless." Hoth the opener of the debate, Mr. £ A. Glen, and the opposer, Mr. Edison Thomas, revealed a knowledge of military aeronautics that is most encouraging to meet with, outside aeronautical circles. Mr. Glen commenced his opening speech with a few preliminary remarks about the hi->lory of aviation, including a brief review of the formation of the Royal Flying Corps, and pointed out how the love for sport in all its various branches appeared to have developed qualities in the British pilot which rendered him superior to those of other nationalities. Coming to the usefulness of aircraft, the opener divided into seven main headings the various ways in which aeroplanes had proved their utility: (1) For scouting, (2) as imple ments fur driving away enemy scouts, (3) for range finding, working with artillery, (4) for conveying messages, 5) as destroyers of objects of military value, (6) for the location and destruction of submarines and mines, and (7) as convoys to transport columns. Under the fourth heading, Mr. Glen called attention to four different ways in which aeroplanes were proving useful in conveying messages : (a) Sending artillery results by wireless (b) as bearers of long despatches', where the aeroplane had been found to be quicker than the field telegraph, (c) for maintaining communication between troops, and (d) for dropping leaflets to inhabitants of besieged towns. Of the instruments employed by aeroplanes for carrying out the particular branch of their service, referred to under the 5th heading, the opener mentioned machine guns, explosive bombs of various weights, incendiary bombs and flechettes. Mr. Glen pointed out that, compared with the utility of the aeroplane, the advantages of lighler-than air craft are few, while their attendant disadvantages are numerous. Of the former, mention was made of the greater carrying power of a Zeppelin, its hovering power, the steadiness of its platform (for shooting and bomb-dropping), its capability of travelling by night, and the silence of its engines, whilst the dis- EFFECTIVE FACTOR? advantages of lighter-than-air craft were enumerated under seven headings: (1) Vulnerability from above, anddefencelessness against anything above them, since it has been found unsafe to mount guns on top of a Zeppelin owing to the leakage of gas ; (2) they are weather-shy ; (3) their speed is less than that of the aeroplane ; (4) they have less manoeuvring power. (In this connection the opener pointed out, that it is interesting to compare aircraft rela tively with the ships of Drake's fleet when he secured his victory over the Spanish Armada. It was due mainly to the mobility of the smaller ships, which were able to out-manceuvre the larger, but more sluggish, ones of the Armada.) (5) Cost of construction ; (6) need for huge quantities of gas ; and (7) limit of altitude. In opposing the motion, Mr. Edison Thomas complained that the opener had partly anticipated him by handling a number of the points in favour of lighter-than-air craft, or, as the opener was pleased to call them, "gasbags." He thought, however, that th< re were several points on which the opener had laid himself open to criticism. For instance, the high speed at which an aeroplane travelled must be considered a disadvantage for scouting purposes, since it did not allow of a sufficiently thorough examination of the country over which it was flying. As an instance, the opposer mentioned how one year during the German manoeuvres the aero plane scout sent out was totally deceived by dummy guns placed in spoof trenches, and manned by dummies, so that the scout brought back the report that great numbers of troops were massed at a certain position, when, as a matter offact, they were miles away. Another point brought forward by the opener was contested by the opposer, via., that the aeroplane had proved quicker than the field-telegraph for sending long despatches. He had no doubt that the opener had good authority for this statement, but, on the face of it, he would have thought that wireless or a field telephone with underground wires would have been the quicker. As regards the employment of aeroplanes for dropping pamphlets to the inhabitants of besieged towns, Mr. Thomas failed to see any great utility in this particular respect, since, he said, the leaflets could not be scattered broadcast with any certainty of their dropping where desired, but would have to be dropped in a bundle. One would then have to hope and pray that this bundle would be found by some friendly person who would be willing to act as a sort of glorified newsvendor in distributing the pamphlets. With regard to the employment of seaplanes, for locating sub marines and mines, Mr. Edison Thomas pointed out that this, as far as he was aware, could only be successfully done in clear weather and with a calm sea. As regards the destructive properties of aero planes, the opposer was inclined to think that these were less than 304
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