An Examination of the History of the Concept of Personal Flying Methods and Machines

he Chairperson of LosCon 38 posed the question "Where's My Flying Car?" as the theme for this years convention. I propose to answer it first by saying, "It's here already!" The idea of a personal flying machine, device or method has been in the human mind for hundreds if not thousands of years. In the near East, the fantasy of a "Vimana" or "flying carpet" has been a tradition of the many classic stories of early times. Tribal leaders and shaman of many lands have taken on, spiritually, the powers of the birds in their many rituals and ceremonies. The Greeks and Romans had their winged gods, Mercury, Bellerophon and his Pegasus and secretly wished they had these powers. Do the names Daedalus and Icarus have a familiar ring? The flying gadget has been a staple of science fiction and fantasy since Cyrano de Bergerac, Jules Verne and H.G. Wells. In the twentieth century world expositions, magazines and tv ads have featured promises of a new world filled with modern homes and flying cars. In the post-war era children's radio and televison shows filled little hearts with stories of a hopeful future and modern miracles. Didn't every kid want to be like George Jetson, living in a futuristic house and having a personal flying car? After all, "My Favorite Martian" kept his space ship in a garage! Well, so much for hopeful wishes and fantasy, you say... but, where is my flying car? Why hasn't it become a reality? The truth is... it has been with us for a very long time... almost as long as there have been stories about it. In the 16th century, a farmer named Besnier actually got tired of all the talk and decided to do something. He fashioned a set of gliding wings out of four pieces of board and two poles, some rope and hinges. He was able to ride this "sky-cycle," flapping his crude "wings" and managed to sail across the countryside until he alit on another roof. It was a short flight, and he wasn't able to actually "take off," but it showed others that it was possible...

he history of the flying vehicle is entwined with the history of flight itself... Down through the ages many brave souls have risked life and limb trying to realize that age-old dream... of personal flight. To get seriously into our search for the flying car, we have to look at the more serious attempts of flight... Flying Timeline: efore Orville and Wilbur Wright successfully flew the first heavier-than-air airplane at Kitty Hawk, N. C., in 1903, humans had been attempting flight for thousands of years. Ovid published his collection of myths, "Metamorphoses," at the very beginning of the first millennium, which included the tale of Daedalus and Icarus escaping the island of Crete by way of glue and feathers. Actors at Roman feasts frequently entertained simply by jumping from tall heights with nothing but feathered arms, falling to their deaths. King Bladud (c. 850 B.C.) One of the very first recorded attempts at human flight, however, goes as far back as 850 B.C. to Troja Nova, or New Troy, where the legendary King Bladud made his mark on aviation history. King Bladud also practiced necromancy, or communication with the spirits of the dead. Legend says he used necromancy to build a pair of wings that attached to his arms. Bladud made an attempt to fly at the temple of Apollo while wearing the wings, but the mythical figure unfortunately didn't get the right blueprints from the spirits: He fell to his death. Al-Djawhari (c. 1000) Turkish De-Flight Sciences such as mathematics and astronomy were very important to Islamic scholars during the Middle Ages, and flight became a sacred ideal to Turks well before it was seriously discussed in Europe. Around the 13th century, the Turkish lyric poet Sultan Veled included the word "ugmak" in his poems, which means both "heaven" and "to fly." Experiments with gunpowder and rockets were just as revered, and, according to anecdotes, one man named Lagarî Hasan Celebi even mounted a rocket, lit it and flew over a lake before falling in unharmed.The first more or less reliable historical account of attempted flight happened around the year A.D. 1000 in Nisabur, Arabia. The would-be aviator in question is al-Djawhari, the great Turkish scholar from Farab. Sometime between the years 1002 and 1010 (several different accounts vary), al-Djawhari tied two pieces of wood to his arms and climbed the roof of a tall mosque in Nisabur. According to eyewitnesses, the scholar's bold move drew a large crowd, to whom he announced: "O People! No one has made this discovery before. Now I will fly before your very eyes. The most important thing on Earth is to fly to the skies. That I will do now." Al-Djawhari fell straight to the ground and was killed, stamping into history the first recorded attempt at human flight. Leonardo da Vinci's Complex Ornithopter (c. 1505) During his 30s, Leonardo also took a great interest in flight, and by about 1505 had collected around 20 years of theory on flight. It is around this time that some think Leonardo built a complex ornithopter, a machine with flapping wings that closely mimicked the anatomy of birds. No one really knows if Leonardo actually built a model of and tested his ornithopter. Many of his designs remained on paper during his lifetime and weren't built until much later. In 1550, however, one of Leonardo's associates, Cardanus, wrote that he had tried "in vain" to get the ornithopter off of the ground, so there's a possibility that the Renaissance man took his machine for a few disastrous spins. Philippe le Picard's Laborer (c. 16th Century) One 16th-century writer named Phillippe le Picard, who went by the penname of Philippe d-Alcripe, wrote a morality tale, infusing his fable with a bit of humor. Le Picard's moral tale involves a French laborer, known across Normandy as a great swearer and drunkard. The fable says that one day, when the laborer had too much curdled milk to drink, he decided on a whim to make himself a flying apparatus and have a bit of fun. Without notifying his wife (who most likely would've scolded and slapped him into his senses), the worker cut a winnowing basket, used to separate corn kernels from husks, in half, fashioning them to his back. After failing to lift himself off the ground, the man got a brilliant idea: He needed to find a tail in order to look and act more like a bird. Being a laborer, the man had a nearby shovel, which he placed between his legs and secured with his belt. Climbing to the top of a nearby pear tree, he jumped off, soared through the air for a split second and then fell headfirst to the ground, where he broke his shoulder. The shoulder never healed properly, preventing him from making any more drunken, misguided attempts. João Torto (June 20, 1540) The small European country of Portugal has a long history of aviation: Attempts at flight go back as early as Medieval times, and the Portuguese Air Museum dates back as far as 1909, only six years after the Wright brothers flew at Kitty Hawk, N.C. One famous attempt, however, made the wrong kind of history, ending up in failure. The man who took the hit for Portuguese aviation history was João Torto. A true Renaissance man, Torto was a man of many trades: He was a nurse, a barber, a certified bleeder and healer, an astrologer and a teacher. Unfortunately, Torto also had a big head about his well-rounded education, and decided he wanted another title added to the list -- aviator. Using two pairs of calico cloth-covered wings attached to his arms and an eagle-shaped helmet, Torto jumped from the cathedral tower in St. Mateus square on June 20, 1540 at 5 p.m. (in front of a large crowd, of course) and fell a short distance to a nearby chapel. Besnier the Locksmith (1678) Much of the history of aviation involves a long line of people who are altogether unassociated with flying but for a brief stint. One such person was Besnier, a locksmith from Sablé, France, who decided to put locks aside for a moment and try his hand at a flying machine. Besnier had a bit more sense than the eccentric Desforges, and he understood that he didn't quite have the right materials to build a flying machine that would let him take off from the ground. Instead, the locksmith designed an apparatus made of two wooden rods placed over the shoulders, on each of which was attached two wings. The rods, according to the illustration, were also tied to the pilot's feet, which helped to pull the wings down alternately and flap the folded wings. Besnier never attempted to flap violently from the ground; he tested his contraption out on short distances, jumping from chairs, tables, window sills and, eventually, the tops of garrets and over rooftops. Although he became fairly skilled at floating for short distances, attempts at long distance flights only ended up in failure. The Marquis de Bacqueville (1742) The Marquis de Bacqueville (c. 1680-1760) appeared to have had very little experience in the way of flight, but one morning in 1742 he woke and announced his intent to fly from one side of the river Seine to the other. More specifically, the marquis planned to launch from a point in his mansion, located in Paris on a quay near the river, fly a distance of about 500 to 600 feet (152 to 183 meters) and land in the Jardin des Tuileries, the gardens situated near the palace of the same name. A large crowd came to witness his attempt on the planned date in the same year. With large wings resembling paddles attached to both his hands and feet, the marquis jumped from a terrace on his mansion and proceeded to float toward the gardens. For a moment, the marquis appeared to have control, but after a short while he began to waver, and he eventually fell, slamming onto the deck of a barge and breaking his leg. Admitting defeat, the marquis gave up flying for good. Pierre Desforges (1770-1772) In 1770, the Abbé constructed a pair of wings, but Desforges wasn't confident enough to try them out himself. Instead, he attached the wings to the nearest peasant and covered him from head to toe in feathers. Leading him up to the top of a belfry, Desforges proceeded to instruct the peasant to start flapping and throw himself into the air, assuring him the wings would work. Desforges gave up after the peasant outright refused to commit suicide, and set to work on gathering funds to build a more reliable flying contraption. After two years of hard work, Desforges eventually unveiled his flying machine, a six-foot (1.8-meter) long gondola covered by a canopy and attached with wings, the latter of which had a wingspan of nearly 20 feet (6.1 meters). The Abbé sought the help of four more peasants to carry the flying gondola up to the top of the Tour Guinette, a lookout tower near his church. This time Desforges was the one flying, as he most likely assumed that word had spread among the peasants to look out for any clergyman seeking aid near heights. In front of a large crowd, the peasants pushed Desforges over the edge, whereupon he promptly fell straight to the ground. The churchman suffered no more than a broken arm.

In 1781 Blanchard, who subsequently became a fervent aeronaut, and who was the first to cross the British Channel in a balloon, constructed near Paris a flying chariot with four wings, measuring in the aggregate some zoo sq. ft. in area. He never exhibited the apparatus in public, having probably ascertained by private experiment that he was unable to move the wings rapidly enough to produce any useful effect. Bourcart, in 1866 experimented with an apparatus consisting of four wings with a feathering action, so that it presented the edge to the air upon the up stroke and the broad side upon the down stroke, but the results were insignificant, and the experiment was abandoned. The supporting areas measure approximately some 36 sq. it., but are only effective upon the down stroke. In 1873 Professor Pettigrew published his work on "Animal Locomotion," in which he called attention to the fact that birds in flapping flight, flex their wings so as to resemble a screw propeller, and that the tips describe a figure of 8 motion. This led to the inference that man had not succeeded in raising himself with wings because he had not hit upon the right motion. 1879 Dandrieux constructed an apparatus in which the wings were attached to an oblique axle, so as to describe a figure of 8 movement. This is represented in fig. 6, and there being but two wings in place of four, the supporting surfaces measure about 32 sq. ft. in area. The result was not satisfactory; a partial alleviation of the weight was obtained, but nothing like human flight or the hope of it. Charles Spencer exhibited an apparatus consisting of a pair of wings measuring each 15 sq. ft. in area, to which was attached an aeroplane measuring 110 ft. more, and also a tail like a boy's dart, and a longitudinal keel-cloth to preserve the equilibrium, the whole weighing 24 lbs. and giving a sustaining surface of 140 sq.. ft. As Mr. Spencer was an athlete, he was enabled, by taking a preliminary run down a little hill, to accomplish short horizontal flights of 120 to 130 ft., in which he was wholly sustained by the air. He weighed 140 lbs., and his apparatus, which, it will be noted from the description, differed from those which propose "wings for man" by the addition of an aeroplane, measured 0.85 sq. ft. to the pound, or about the proportion of the larger soaring birds. The experiments attracted great attention at the time, but were not sufficiently encouraging to warrant pursuing the matter further. Charles Spencer exhibited an apparatus consisting of a pair of wings measuring each 15 sq. ft. in area, to which was attached an aeroplane measuring 110 ft. more, and also a tail like a boy's dart, and a longitudinal keel-cloth to preserve the equilibrium, the whole weighing 24 lbs. and giving a sustaining surface of 140 sq.. ft. As Mr. Spencer was an athlete, he was enabled, by taking a preliminary run down a little hill, to accomplish short horizontal flights of 120 to 130 ft., in which he was wholly sustained by the air. He weighed 140 lbs., and his apparatus, which, it will be noted from the description, differed from those which propose "wings for man" by the addition of an aeroplane, measured 0.85 sq. ft. to the pound, or about the proportion of the larger soaring birds. The experiments attracted great attention at the time, but were not successful. in September, 1890, Mr. W. Quartermain, who exhibited an explosion engine for aerial purposes in 1868, in which the motive power was derived from the gases generated from a species of rocket composition. wrote a letter to the London Engineer, in which he stated that he had abandoned his attempts to procure a light and energetic motor from hydrocarbonous matter, in favor of man's weight and muscular power, which he considers preferable, and was then engaged in experimenting with an apparatus consisting of four wings, formed after the stag beetle type, each 10 1/2 ft. long by 2 1/4 ft. wide, opposing go sq. ft. of expanse of surface to the air. This arrangement weighed 350 lbs., including 212 lbs. for the weight of the operator, who by working both handles and treadles, thus bringing all his muscles into action as well as his weight, was enabled to wave the wings, which are 25 ft. from tip to tip, so as to produce a double stroke for every single stroke of his body on the motive shaft. He describes the result as resembling that of domestic fowls flapping their wings without lifting themselves from the ground, but is of opinion that the uplifting force was greater than his weight of 212 lbs., and believes that further improvements in the mechanism, with more skilful workmanship, might produce an ascensive force greater than the whole weight of 350 lbs. This may well be doubted, for not only will it be shown hereafter that the energy of man must be less than that of birds, but none of the latter fly with so small a bearing surface in proportion to the weight-0.26 square foot to the pound-as in Quartermain's apparatus. It has been suggested, however, that umbrella-like surfaces might prove more effective than wings, and increase the uplift to be derived from the air. Such contrivances were experimented upon by Sir George Cayley, who constructed, about 1808, a pair of wings which appear from the drawings to have been a fabric stretched tightly over a dished frame, this framework consisting of two ribs at right angles to each other, bent and tied across so as to secure rigidity. This double umbrella contained 54 sq. ft. and weighed only 11 lbs., and the inventor says: "Although both these wings together did not compose more than half the surface necessary for the support of a man in the air, yet during their waft they lifted the weight of 9 stone" (126 lbs.). It is not stated with what speed they were wafted nor with what power, but that the result did not promise to provide "wings for man" may be inferred from the fact that Sir George Cayley, in a very valuable series of articles in Nicholson's Journal for 1809 and 1810, starts out with the assertion that, in order to accomplish aerial navigation, "it is only necessary to have a first mover which will generate more power in a given time, in proportion to its weight, than the animal system of muscles." The next experiments with umbrella wings attracted attention all over Europe. They were carried on by J. Degen, a clockmaker of Vienna, from 1809 to 1812 with the apparatus shown in fig. 7. It consisted of two wings 8 1/2 ft. wide and 22 ft. across in the aggregate, each being shaped somewhat like a poplar or an aspen leaf. They were stretched upon an umbrella-like frame and thoroughly braced back, both above and below, to a central stick by a number of small cords. The supporting surfaces consisted of bands of taffeta so attached as to have a valvular action, in order to imitate the supposed action of the feathers of birds, and the total supporting surface was 130 sq. ft., while the weight, without the operator, was stated at 20 lbs. With this apparatus Degen, was stated, in 1809, to have risen to a height of 54 ft., by beating his wings rapidly, in presence of a numerous assembly m Vienna, and all the newspapers began to publish accounts of the performance. These descriptions failed to mention one important addition. Degen was also attached to a small balloon capable of raising 70 lbs., so that the uplift exerted by the wings was only 70 lbs. of the 160 lbs. weight of the operator and his apparatus. In 1812 Degen; went to Paris to exhibit his invention. He then stated that the balloon was of no sort of utility in obtaining headway, but that it was necessary as a counterpoise to maintain his equilibrium and to lighten his muscular efforts. He evidently expected by the action of his wings to drag the balloon along in still air while it lifted part of his weight He gave three public exhibitions in Paris, but unfortunately for him, as there was wind upon each occasion, he was blown away, and on the third attempt he was attacked by the disappointed spectators, beaten unmercifully, and laughed at afterward as an impostor. The umbrella idea had, however previously proved to be of value for parachutes, and in 1852 Letur devised the apparatus shown in fig. 8. with which he expected to direct himself through the air. by means of the wings and tail, first starting from an elevation. In 1854 he ascended from Cremorne Gardens in London suspended about 80 ft. below a balloon manoeuvred by Mr. Adam, the areonaut, who was assisted by a friend. Letur performed several evolutions in the air by means of his wings, none of them apparently very conclusive, but in coming down near Tottenham, the wind carried the apparatus violently against some trees, and poor Letur received injuries which resulted in his death. His apparatus measured about 660 sq. ft. in bearing surface, and had he been entirely detached from the balloon, it is possible that he might have reached the ground in safety; but it is evident that his wings would have been as of little service in enabling him to obtain more than a slight horizontal direction. a Belgian shoemaker named De Groof designed, in 1864, an apparatus which was a sort of cross between beating wings and a parachute. His plan was to cut loose with it from a balloon, and to glide down in a predetermined direction by manoeuvring the supporting surfaces. He endeavored to make a practical experiment, both in Paris and in Brussels, but it was only in 1874 that he succeeded in doing so in London. The apparatus is shown in fig. 9. It consisted of two wings, each 24 ft. long, moved by the arms and the weight of the operator, and of a tail 20 ft. long, which could be adjusted by the feet. De Groof first went up on June 29, 1874, from Cremorne Gardens, London, attached to the balloon of Mr. Simmons. He came down safely, and claimed to have cut loose at a height of 1,000 ft., but it was subsequently stated by others that in point of fact he had not, upon this occasion, cut loose at all, but had descended still attached to the balloon. In any event, he went up again on July 5 following, with the same aeronaut, and on this occasion he really did cut loose. The result was disastrous. As soon as, in the descent pressure gathered under the moving wings, they were seen to collapse together overhead and to assume a vertical position, when De Groof came down like a stone, and was killed on the spot. Had the wings been prevented from folding quite back, by means of suitable stops, the descent might not have proved fatal. The area of the wings and tail, as extended horizontally, is said to have amounted to 220 sq. ft., while the weight of the man and machine was 350 lbs., or at the rate of 0.65 square foot to the pound. This corresponds to a pressure of 1.54 lbs. to the square foot, which would be generated by a velocity of 25.7 ft. per second, or a free fall from a height of 10.3 ft.; an unsafe distance for an ordinary person, but not for a trained acrobat. Cocking, who was killed in 1836 in an experiment with a parachute shaped like an inverted umbrella, to attempt a descent with an apparatus previously untried to test its strength and behavior. A few prior experiments, with a bag of sand, instead of the man, would have exhibited the action that was to be expected. Another class of inventors of "wings for man" have endeavored to secure safety by the use of large bearing surfaces. The first of these was probably, Meerwein, architect to the Prince of Wales, in 1784 who an apparatus shaped like the longitudinal section of a spindle, separated into two wings, by a hinge at the center. It measured nearly 200 sq. ft. in area, and probably was never tried, but if it had been, it is quite certain that a man could never have imparted to the wings sufficient velocity to perform any useful effect. The next proposal of this class was that of Bréant, who designed in 1854 the apparatus shown in fig. 10. It consisted of two wings, each measuring about 54 sq. ft. in area, and provided with three valves to relieve pressure on the up stroke. The down stroke was to be produced by the joint action of the feet and hands, and the wings were to be drawn back by elastic cords. It is not known whether it was ever tried, but it would have proved ineffective if it had been. The next design was that of Le Bris in 1857, which is exhibited by fig. 11. By noting the little man working the levers in the center, the proportions of the apparatus, which seems to have measured some 550 sq. ft. in area, will be appreciated. It is said to have been experimented with in a small model, in which levers pulled down the wings which were then drawn back by springs, but it did not succeed in rising into the air, as was hoped by the inventor. While the inventors who experimented with flapping wings, with which they tried to raise themselves on the air by muscular effort, doubtless had it in mind eventually to substitute artificial motors, if only they could catch the trick by which the bird flies, there have been a few others who have at the outset designed flapping wings, to be moved by some primary artificial motor. As they generally knew of no such motor, within admissible limits of weight in proportion to its energy, such designs have remained mere projects, and but few experiments have been made The proposal of Gérard, in 1784, shown in fig. 12, seems to have been among the first. It apparently provides, in addition to the body and wings, for a steering arrangement in front, and for feet with springs to land upon. The inventor omitted to state in his printed description what motive power he intended to use, but an inspection of the drawing suggests the conjecture that the apparatus was to be propelled in part by escaping gases, like a rocket, and in part by flapping the wings through the medium of a gunpowder engine; proposals and experiments with such motors antedating, as is well known, those with the steam-engine. Be this as it may, soon after the success of the locomotive engine on the Liverpool & Manchester Railroad, Mr. F. D. Artingstall endeavored to compass an aerial locomotive. He constructed a very light steam-engine, suspended it by a cord from the ceiling, and to the piston-rod he attached wings, which were so constructed that they opened somewhat like a Venetian blind on the up stroke and closed during the down stroke, moving through an arc of 80°. When steam was turned on the wings worked vigorously, but the machine jerked up and down, rushed from side to side, and, in fact, performed all kinds of gymnastic movements except flight. This experiment was terminated by the explosion of the boiler, and a second attempt, in which it was intended to use four wings instead of two, in order to keep up a continuous buoyancy, resulted in a second explosion; after which the experiments were abandoned. In 1868 Mr. Artingstall, in a communication to the Aeronautical Society of Great Britain, stated the weak point in his various experiments to have been the lack of suitable equilibrium. Every experimenter with aerial apparatus has doubtless encountered the difficulty of obtaining in a machine that equilibrium which the bird maintains by instinct, and also of deriving continuous support from the flapping of one pair of wings. These are probably the reasons which led Struvé and Telescheff to design, in 1864, the apparatus shown in fig. 13, in which five pairs of wings are attached to a central plane. The only description accessible to the writer states that the wings were moved by human force acting upon a spring, but it is evident that the apparatus was intended to be driven by artificial power, if the designers could only find one sufficiently light for that purpose. That they did not succeed in this seems to be a fair inference from the fact that the machine was not tested by experiment. At the Exhibition of 1868. of the Aeronautical Society of Great Britain. Mr. I. Palmer exhibited a pair of wings (to be driven by power) attached to a rotating axle, and so arranged that they expanded in the descent and closed in the ascent, like the action of a duck's foot in swimming; this motion being obtained in a remarkably simple manner by a roller running on an eccentric cam, which could be instantaneously changed in position, so as to convert the vertical lifting power into one of horizontal force. It does not seem to have been applied to any flying machine. At the same exhibition Mr. I. M. Kaufmann, engineer of Glasgow, exhibited the working model represented in fig. 14, which was intended as the precursor of an aerial steam machine weighing 7,000 or 8,000 lbs. The apparatus consisted of a steam boiler and engine, mounted upon wheels, and propelled by two long wings, which. during the down stroke, were set at an inclined direction backward, and were caused to turn at a forward angle during the up stroke. The main portion of the weight was to be sustained by superposed aeroplanes, and hence the machine should perhaps be described under that head, but it is here included under the head of wings, because of the mode of propulsion. The model weighed 42 lbs., and during the experiments with it its boiler, owing to its small size, was not fired, steam being supplied from an independent boiler. With steam pressure at 150 lbs. to the inch, the wings made a short series of furious flaps, and one of them suddenly gave way about 2 ft. from its base, upon which the other one failed also. The inventor stated that he was then engaged in the construction of a larger machine on the same principle, but since then nothing more has been heard of it. He proposed to secure stability by letting down or raising up a long "pendule" with telescopic joints, so as to adjust the center of gravity and keep the machine in a horizontal position, but it may well be doubted whether this would have proved effective. At a meeting of the British Aeronautical Society, in 1871, Mr. R. C. Jay exhibited a model to illustrate a method which he proposed in order to use wings of any length and weight without loss of power. This consisted of two pairs of oscillating wings moving on the same shaft. It was expected that the forces generated by their motion would hold the machine is equilibrium, and that one pair of wings would be aided by the current of air, or whirlpool, produced by the movement of the other pair. This does not seem to have answered, for in 1877 the same inventor presented a model to the same society, illustrating a method of obtaining a figure of 8 or sculling action with one pair of wings, but at the same time Mr. Jay candidly stated that "although he had made a great many experiments, he had not yet succeeded in making a propeller (wings) sufficiently simple and effective for practical purposes." It is said that about the same time an optician of Leipsic made a small steam bird, mounted on a globular steam boiler and actuated by a cylinder of 2 in. stroke, working wings 32 in. long. This machine would rise vertically 3 ft., the wings making about three beats during the flight, but the boiler limited the performance. It contained spirits of wine only sufficient for 38 seconds, and the apparatus was but a toy. In 1871 Prigent designed the apparatus shown in fig. 15, which was evidently suggested by the dragon-fly; this is a favorite idea with aviators, who, as we have seen already, have proposed the combination of two pairs of wings over and over again. It was intended to be driven by steam, but although in that same year Moy had produced a steam-engine and boiler weighing but 27 lbs. per horse power, and Stringfellow, in 1868, has shown one claimed to weigh but 13 lbs. per horse power (both applied to aeroplanes), no attempt seems to have been made to experiment with Prigent's device. The fact is, that even the weight of the engines mentioned was too great, for it did not include the fuel and water, which for a noncondensing steam-engine would amount to about 26 lbs. more horse power per hour, and this did not compare favorably with the motive power of birds. The pigeon, for instance, is known, both by dynamometric experiment and computation, to develop in ordinary flight from 160 to 425 foot-pounds of energy per minute for each pound of his weight, and as his pectoral muscles, which constitute his engine, generally compose 10/43 of his weight, we have for the weight of his motor from (33.000 * 10)/(425 * 43) = 18 lbs. to (33.000 * 10)/(160*43) = 48 lbs. per horse power developed, including the fuel which enables him to fly for 10 to 12 hours at a stretch. and in 1871 Jobert brought out his first mechanical bird, shown in fig. 16, driven by indiarubber in tension. The wings were arranged so as to change their plane automatically while flapping, in order to imitate the flexions of the natural wings, and the equilibrium was secured by adjusting the center of gravily so as to correspond with the center of pressure due to the angle of flight. In 1872 Pénaud who had already succeeded (1870 and 1871) in compassing flight with the superposed screws and with the aeroplane, which will be noticed hereafter, by the force of twisted rubber, applied the same motor to a mechanical bird, which is shown in fig. 17. The wings beat straight down, and the propulsion is obtained from the flexion of their outer edges produced by the reaction of the air. The bird is unable to rise from the ground, but upon being thrown off the hand it first descends some 2 ft., and then, having acquired the initial velocity needed for support, it flies for a distance of 50 ft. in 7 seconds, rising at the same time about 8 or 9 ft. above the point of departure, the equilibrium being perfectly maintained by the tail. Simultaneously with this M. Hureau de Villeneuve, the permanent Secretary of the French Aeronautical Society, brought out his mechanical bird, which is shown in fig. 18. In this the plane of the wings is inclined at an angle of 45°, and the power is obtained from twisted rubber. In consequence of the peculiar motion of the wings, this model was able to start direct from the ground, but owing to the limited power of the rubber spring it only rose to the height of 4 ft., and then descended, forming a parachute. It was subsequently modified so that it would fly horizontally for a distance of 24 ft., at a velocity of 20 miles per hour. M. De Villeneuve has been promoting aviation by flapping wings for the past 25 years. He has, first and last, designed something like 300 experimental models, so that his garret is a complete aviary of artificial birds. He built, some years ago, a huge steam bird on the model of a bat. Being aware that there was at that time no sufficiently light and reliable steam-engine with its boiler to furnish the power required, he placed only the engine on the bird, and connected it by a hose with a boiler on the ground. Upon trial, as soon as the steam was turned on the wings beat violently, and the apparatus rose with the inventor aboard. He grew nervous for for fear that he would get beyond the length of his hose, and shut off steam suddenly, upon which the bird fell and smashed one of its wings. It is still in existence, and the inventor is awaiting the development of a very light motor in order to resume his experiments with this great bird, which is some 50 ft. across. In 1872 M. Jobert brought out his second mechanical bird, shown in fig. 19. This is driven by twisted rubber, as being more manageable than rubber in tension, and consists of four wings beating alternately in pairs-as a horse trots--in order to produce continuous and uniform support and equilibrium, instead of the jerking motion observable in other apparatus. This flew fairly well, but a measurement of the foot-pounds developed and of the results obtained, in this as well as in the three other mechanical birds previously described, led to the inference that there was great waste of power, as compared with that of birds. This was attributed to the rigidity of the front edge of the wings in all these models, and accordingly in 1876 Tatin took the problem up again and succeeded, by a double eccentric working two levers connected to the front edge of the wing, in giving it a twisting motion similar to that of the bird. His apparatus flew some 65 ft., with rather less weight of rubber. In 1889 Pichancourt carried the matter still further in the mechanical bird shown in fig. 20, in which there is a triple eccentric, each one actuating a lever fastened to a different point in the wings. His larger models, measuring 171 in. from tip to tip of wings, and weighing 1 1/2 oz., are said to have flown up to a height of 25 ft. and to a distance of 70 ft. against a slightly adverse wind. M. De Louvrié designed, in 1877, the apparatus shown in fig. 21, which he calls the "Anthropornis," and which consists of a pair of wings, resembling those of the swallow, fastened to a hull mounted upon wheels, and intended to be actuated by a steam-engine or a petroleum motor. A spring is to contribute to the downward stroke, and is to be raised by the motor on the up stroke. M. De Louvrié is a veteran in promoting aviation, and his writings show a better understanding and firmer grasp of the question than most of those which nave been published on this intricate subject. He had proposed, in 1863, a sort of kite-like flying machine, which will be noticed under the head of Aeroplanes, and it is said that, in 1888, he presented his latest views before a commission of the French Academy of Sciences, supplementing them with certain experiments, from which he drew the conclusion that an apparatus capable of carrying four passengers needed no more than 3 horse power to drive it at the rate of 67 miles per hour. It may be inferred that the French Commission was not convinced, from the fact that no action has been taken upon the proposal.