timberland oxford shoes Australian aviation pioneer 1850
Lawrence Hargrave (1850 1915)Australian aviation pioneer, inventor, explorer, mason and astronomer.”If there be one man, more than another, who deserves to succeed in flying through the air, that man is Mr. Laurence Hargrave, of Sydney, New South Wales. In 1872 he came to Australia in search of gold, but the ship chartered by the group of adventurers was wrecked off the Queensland coast.
Hargrave with his Engine No.35, single cylinder two stroke petrol engine driving twin ‘flappers’, 1908Download a 500pixel image [300dpi] Philippe Gervais
Hargrave compressed air powered ‘quadraplane'(details to follow Ed.)Download a 500pixel image [300dpi] Philippe Gervais
In 1892 Hargrave discovered that a curved wing surface appeared to give a greater lift than a flat supporting surface. Then he turned his attention to research into the behavior of various types of kites. During the course of his experiments he found out that a curved surface had twice the lift as a flat one, and next he discovered that a kite with two separated “cells” or double planes, had the greatest stability and oaring power.
Man carrying glider, 1893 Shaw, W. Hudson and Ruhen, Olaf, 1977, p.72
While the Wright brothers denied that they owed anything to Hargrave, his discovery of the cellular kite and his investigations into the superiority of curved wing surfaces played an important part in European experimental work which culminated in the first public flight by Santos Dumont in France in 1906. By demonstrating to a sceptical public that it was possible to build a safe and stable flying machine, Hargrave opened the door to other inventors and pioneers. Leading the race was Hargrave, a quintessential nineteenth century gentleman scientist of independent means. A gifted explorer, astronomer, amateur historian, and practical inventor, Hargrave devoted most of his life to constructing a machine that would fly. He believed passionately in open communication within the scientific community and would not patent his inventions. The Wright brothers had access to Hargrave’s work through the aviation annuals published by James Means, and Octave Chanute’s Progress in Flying Machines. Chanute, who corresponded with the Wright brothers, devoted a section of his book to Hargrave’s experiments. The French (who thought that France was the cradle of aviation) freely acknowledged Hargrave’s influence: Alberto Santos Dumont was the first European to fly a heavier than air machine constructed of Hargrave box kites in 1906. When Gabriel Voisin built the first commercially available aircraft, based on the stable lifting surfaces of Hargrave’s box kites, he called them “Hargraves.”In 1889 Hargrave revolutionised engine technology by inventing the radial rotary engine, which reappeared (unacknowledged) in modified form in 1908 as the French Gnome engine. The only museum that would meet his terms was the Deutsches Technological Museum in Munich. It is ironic that most of Hargrave’s 176 working models were destroyed in the Allied aerial bombardment of Germany during World War II. His 1902 design was put to the test in 1992 when students at the University of Sydney rebuilt his aircraft from the original blueprint, replacing Hargrave’s power plant with a modern one.
Compton’s Encyclopedia Web Link Electronic Library
1995 Omni Publications International Ltd. Hargrave takes out no patents for any of his aerial inventions, and he publishes from time to time full accounts of them, in order that a mutual interchange of ideas may take place with other inventors working in the same field, so as to expedite joint progress. He says:”Workers must root out the idea that by keeping the results of their labors to themselves a fortune will be assured to them. Patent fees are so much wasted money. The flying machine of the future will not be born fully fledged and capable of a flight for 1000 miles or so. Like everything else it must be evolved gradually. The first difficulty is to get a thing that will fly at all. When this is made, a full description should be published as an aid to others. Excellence of design and workmanship will always defy competition.”M. Hargrave is probably correct in his reasoning; for the history of all new methods of transportation teaches that the original inventor seldom receives pecuniary reward for the contrivance which is the first to succeed, but nevertheless he is certainly broadly liberal in giving to the world gratuitously the results of his constant studies and labors. He uses exceeding care in determining the different elements which compose the flight of his models. He has carefully registered the sizes of all the parts, the power consumed in each performance, and the length of the flight, together with its trajectory. Hargrave reports regularly the progress of his work to the Royal Society of New South Wales, of which he is a member. The first paper, therefore, presented in August, 1884, was on the Trochoided plane which M. Hargrave next experimented with nearly 50 models intended to reproduce horizontal flight, and in exhibiting some of these and reading his second paper, June, 1885, he said:” If the notion is not that used by birds, it is at all events very like it, and its acceptance or rejection as a scientific truth is of no further interest, as it only remains for practical mechanics to step in and adjust the details to suit the material and the motive power which they may think best for the purpose they have in view; or, in other words, that the solution of the problem of just how a bird flies is of very trifling importance from a practical standpoint, as compared with the judicious variations of the parts of the machine that will have to be made before any return can he expected for money invested in such undertakings.”Some of these models seem to have been driven by clock work, and the motions were those of the “trochoided planes,” as applied to flapping wings; then selecting the best of these models, and making their mean dimensions a standard from which to take a fresh departure, M. M. Hargrave concluded that the screw and the flapping wings are about equally effective as instruments of propulsion, although he rather prefers the latter, as the wings possess several marked advantages. Any currents, he says, initiated during the upstroke are utilized in giving increased efficiency to the down stroke, if the machine has not progressed far enough to be acting upon entirely undisturbed air. Moreover, when steam engines come to be used, there will be only one cylinder needed for both wings, there will be no conversion of reciprocating into rotary motion, and no variable listing moment to be counteracted, while, finally there is less liability that wings shall be damaged in alighting than screw bladesFig. 76 shows the last one (1889) of the india rubber driven machines described by M. HargraveHe calls it the “48 band screw.” The screw is at the stern, and the machine weighs exactly 2 lbs. Its sustaining area is 14.51 sq. ft. (7.26 sq. ft. per pound), and it flew 120 lineal feet with the expenditure of 196 foot pounds of energy, while the preceding machine, weighing 2.09 lbs., with flapping wings, had flown 270 ft. The sustaining surfaces were of paper, pasted on, and after the gum was dry rendered as tight as a drum by blowing a light spray of water over the paper and allowing it to dry. Thus with small, light, simple, and inexpensive models many experiments were made. Hargrave next undertook the construction of a flying machine actuated by compressed air, and, in 1890. he produced the machine illustrated by fig. 77, which he calls his “No. 10 40 5 oz. The engine of the model, of course, retains its precedence as the most important part, and by continuous effort the number of pieces and the difficulties of construction have been so reduced that it is possible to make them by the gross at a cost that cannot exceed five shillings each ($1.25). But this arrangement is only a device to enable the wing tips to act on the required quantity of air with less spread; it may possibly be one of those variations which make all the difference between success and failure. These wings are also distinctly double acting, and it is not quite clear that birds’ wings thrust during the up stroke; but, as previously stated, the question as to the exact movement of a bird’s wing is merely straw splitting, when We have a mechanism that actually flies and is manifestly imperfect in its present mechanical details.”This machine flew 368 ft., with the expenditure as corrected by M. Hargrave of 870 foot pounds of energy. It weighed 2.53 lbs., and the sustaining body plane measured14.78 sq. ft., while the two wings measured 1.50 sq. ft. in area, making a total of 16.28 sq. ft., or, say, 6 .43 sq. ft. This tube is 2 in. in diameter, 48 1/4 in. long, and has a capacity of 144.6 cub. in. Its weight is 19.5 OZ., and the working pressure is 230 lbs. per square inch. The engine cylinder has a diameter of I! in. and a stroke of II in., while the total weight of the engine is only 6 1/2 oz. The piston rod is made fast to the end of the backbone, and the cylinder moves up and down over the piston. Two links connect the cylinder to the Canadian red pine rods which carry the wings. The air is admitted to the cylinder and exhausted by means of a valve worked by tappets. The period of admission continues through the entire stroke. The weight of the wings is 3 oz. To find how much the wings deflected, one was held by the butt and a weight of 71 oz. was put on the membrane 24 in. from the fixed point, and I! in. abaft the wing arm. The deflection produced due to torsional stress, was 3 1/2 By moving the weight half way across the wing it was twisted 8 1/4 The area of the body is 2.128 sq in.; the area of the wings 216 Sq. in., and the total area 2.344 sq. of the whole area, but continued disaster caused its reduction to 23.3 per cent. In a dead calm the machine flew 368 ft. horizontally.”It will be noted that the engine is a marvel of simplicity and lightness. Hargrave consists in the extraordinary length of its supporting body plane, The same surface would carry a far greater load if it were driven broadside instead of lengthwise; but M. Hargrave explains that the plane was purposely so designed in order to insure longitudinal stability. This quality might also be secured by placing a tail far in the rear of a narrow supporting plane, as practiced byP and others. This he did upon the “cut and try” principle a method doubtless the most thorough, the surest,
and the most convincing, but also the most tedious. He found that the direction up or down of the machines in flight was entirely due to the distance of the center of gravity from the forward edge of the body plane, and therefore to the coincidence or otherwise of the center of gravity with the center of pressure. He measured the percentage of area in advance of the center of gravity in his three most successful machines, and found it respectively 19.3, 20 and 23.3 per cent. of the length of the plane, while subsequently he came to the general conclusion that the true position for the center of gravity for a continuous rectangular surface is situated between 0.25 and 0.2 of the length from the forward end, these positions being arrived at “by experience gained by repeated wrecks when groping in comparative darkness.”This independent working out of a complex question well illustrates the perseverance and ingenuity of this experimenter. Hargrave built another flying machine, actuated by compressed air and propelled by beating wings. This is shown by fig. 78. It was of the increased weight of 4.63 lbs., with sustaining body plane of different shape, measuring 29.63 sq. ft., or in the proportion of 6.40 sq ft. per pound. It flew 343 ft., with an expenditure of 789 foot pounds of energy, and therefore showed better results than the previous machine (No. Hargrave next built his flying machine No. 13, which shown in fig. 79, with a body plane still shorter, and he provided it with a two bladed aerial screw, set in the bow and actuated by a three cylinder compressed air engine of the Brotherhood type. This drove it 128 ft. in eight seconds, with an expenditure of 143 footpounds of energy. The apparatus weighed 46.86 oz. (2. 93 lbs.), and exposed 2952 sq. in. or 20.5 ft. of floating surface, being in the ratio of 7.00 sq. ft. Hargrave gives us the time of flight of his machines, so that we may calculate the number of pounds of weight transported in ratio to the horse power. He says:”The time of flight is taken with a sandglass which has a ]orp of string at each end of it. The loop at the sand end is put round the right wrist, and the other loop is held between the right thumb and the receiver, so that the glass is turned the moment that the machine is let go. On the machine taking the ground the glass is put horizontal, and the sand which has fallen is timed at leisure. This seems an obvious enough method of finding the speed, but a practical way to do it was not devised previously.”This showed for No. 13 machine a speed of 10.34 miles per hour which is about what we should have expected from the large proportional surface, it being about in the ratio of the slowest flying birds. This low speed M. Hargrave adopts on purpose, the better to observe the motions of the machines and to save breakage, and he adds quaintly that he sees no objection to this course, so long as the atmosphere is not crowded with flying machines. As No. 13 machine (fig. 79) is reported as having expended 143 foot pounds in eight seconds, we have:Power = 143 8 = 18 foot pounds per second,nearly, and, as it weighed (as reported) 2.93 lbs., we have for the weight sustained per horse power:2.93 X 550 18 = 89.53 lbs. per horse power We will see by the analysis of subsequent performances that M. 14 flying machine, with much the same shape of body surface, but propelled by beating wings instead of a screw. It weighed 3.69 lbs. and exposed 22.84 sq. ft. of surface, being in the proportion of 6.19 sq. ft, per pound. It flew 312 ft. in 19 seconds, with an expenditure of 509 foot pounds, and thus we have:Power = 509 19 = 26.79 foot pounds per secondand for the weight floated per horse power:3.69 X 550 26.79 = 75.75 lbs. 14) M. Hargrave has generously offered to present to some American institution which will take proper care of it, believing it to be one in which “the increased skill in construction acquired by practice is thought to have resulted in an apparatus that, for its weight, it will be hard to excel.” He says in his paper to the Royal Society:”It may be said that it is a waste of time to make machines of such small capabilities, and that no practical good can come of them. But we must not try too much at first; we must remember that all our inventions are but developments of crude ideas; that a commercially successful result in a, practically unexplored field cannot possibly be got without an enormous amount of unremunerative work. It is the piled up and recorded experience of many busy brains that has produced the luxurious travelling conveniences of to day, which in no way astonish us, and there is no good reason for supposing that we shall always be content to keep on the agitated surface of the sea and air, when it is possible to travel in a superior plane, unimpeded by frictional disturbances.”No 16 was another compressed air flying machine with beating wings and somewhat differently shaped body plane. It weighed 4.66 lbs., spread 26.06 sq. ft. of surface, and flew 343 ft. in 23 seconds, with an expenditure of 742 foot pounds. The power was therefore:Power = 742 23 = 32.26 foot pounds per second,and the weight floated per horse power:4.66 X 550 32.26 = 79.45 lbs. His engine No. 17 flying machine of M. Hargrave described in his twelfth communication to the Royal Society of New South Wales, read August 3, 1892. The total weight of the apparatus is 64.5 oz, or 4.03 lbs., including 12 3/4 oz. for the strut and body plane, so that the engine and boiler, including 5 oz. copper tubing (steel pipe could not be got in Sydney), in the form of a double stranded coil, encased in asbestos, and placed just over the backbone of the apparatus. The fuel is methylated spirits of wine, drawn from a tank placed above the boiler, vaporized, mixed with air and spurted into the furnace. As much as 6 .9 cub. in. of water have been evaporated by 1.7 cub. in. more of spirit and water, and thus made to weigh the same as the compressed air machine No. 12, which flew 343 ft., then the steam apparatus No. Hargrave has done still better, for in March 1893, he prepared a paper, which was presented to the Conference on Aerial Navigation at Chicago, August 2 1893 in which he gave data concerning his No. 18 flying machine. This apparatus is also driven by a steam engine which weighs, with 21 oz. of fuel and water, an aggregate of 7 lbs, and indicates 0.653 horse power, or at the rate of 10.7 lbs. The final one was made of 21 lineal feet of 1/4 in. copper pipe, with an internal diameter of 0.18 in., and arranged in three concentric vertical coils whose diameters were 1.6 in., 2.6 in., and 3.6 in. respectively. It weighed 37 oz., but it is now known “that a coil of equal capacity can be made weighing only 8 oz, and still excessively strong.” The cylinder is 2 in. diameter with a stroke of 2.52 in. The feed pump ram is 0.266 in. diameter, and the piston valves 0.3 in. diameter. On one occasion this motor evaporated 147 cub. in. of water with 4.13 cub. in. of spirit in 40 seconds. Hargrave gives no data concerning the flight of his last two (steam) machines. He states that 11 different burners have been tried, and that the flame striking the water boiler first has a tendency to vary the supply of heat to the spirit holder. Hargrave recently turned his attention to experiments upon curved surfaces, and to the seeking for a better disposition of the sustaining surfaces or body planes. He had described the eccentricities of a curved strip in the form of a segment of a hollow cylinder, when exposed to the wind, in his paper No. B, in fig. 80, shows the simplest form. This consisted of two hollow cylinders of aluminum, each 13 in. diameter by 4 1/2 in. deep, mounted 30 in. apart upon a connecting stick, and weighing 14 3/4 lbs. The kite string was attached 11 in. back from the forward section, and as a consequence of the angle of incidence thus produced, the apparatus mounted upon the wind. Its particular behavior is not described in the paper. C, in fig. 80, shows a kite with 16 cells, the length of each being 3 in., by a height of 3 in., and a breadth of 3 in. It was made of cardboard, and the two sections were 22 in. apart, the point of attachment of the kite string being 6 1/2 in. distant from the forward section, while the weight was 10.5 lbs. This seems to indicate that this kite flew at a steeper angle than the preceding, although we should expect the reverse, in consequence of the greater proportion of sustaining surface. M. Hargrave says,”These kites have a fine angle of incidence, so that they correspond with the flying machines they are meant to represent, and differ from the kites of our youth, which we recollect floating at an angle of about 45 , in which position the lift and the drift are about equal. The fine angle makes the lift largely exceed the drift, and brings the kite so that the upper part of the string is nearly vertical.”Kites E and F, fig. 81, are of exactly the same size and weight, consisting of one cell, 4 in. long, 10.7 in. broad by 6.25 in. high, constructed of wood and paper, and weighing 3.25 lbs.; the two sections are 21.25 in. apart, and the string is fastened 7.25 in. back of the forward section. The only difference is that kite E has its horizontal (top and bottom) surfaces curved to a radius of 4.5 in. while all the surfaces of kite F are true planes,
The result is tha