a very early period, retaining, however, all the rites, the spirit, and the doctrines of their old religion that were not abrogated by the Gospel. These Ethiopians, who are genuine Hebrews in race, form the aristocracy of the country, furnishing the dignitaries of church and state and the feudal chiefs of society. There are about 400,000 of these descendants of Hebrew settlers, ruling over 14,000,000. The Negus can raise an army of 200,000 men, of whom more than half are equipped with modern rifles. Diplomatic Missions.-The loss of the battle of Adowa on March 1, 1896, when the Italian army was beaten in pitched battle by the Abyssinians and 12,000 Italians were left dead on the field, led to the renunciation of the protectorate over Abyssinia claimed by the Italians in accordance with their version of the treaty of Ucciali, though the original Amharic text, as interpreted by the Abyssinians, contained no such meaning. The final agreement was facilitated by the intervention of the Pope, who sent Monsignor Macarius to the Emperor Menelek to intercede for the release of the Italian prisoners, and who also bespoke the good offices of France and Russia to bring the treaty negotiations to a satisfactory conclusion. The treaty of peace was finally concluded between Major Nerazzini, the Italian plenipotentiary, and the Negus Menelek at Adis Abeba on Oct. 26, 1896. As in regard to the former treaty, a difference of interpretation arose between the Italian and Abyssinian governments in regard to one of the clauses of the new one. According to the official Italian text, Italy undertook not to cede any portion of her Abyssinian territory to any power except Abyssinia until the frontier between Menelek's dominions and the Italian colony is definitely fixed. According to the Abyssinian version, Italy engaged herself never to cede any part of her Abyssinian territory to any power save Abyssinia. Since the withdrawal of Italy's claim to conduct the foreign affairs of Abyssinia, a right that was not denied by any of the European powers except France and Russia before the new treaty supplanted the treaty of Ucciali, the Negus Menelek has obtained the unquestioned right to treat directly with foreign powers. The European governments were not slow in seeking to establish diplomatic relations and establish their influence at King Menelek's court. The French, whose colony of Obok adjoins Abyssinia, concluded a commercial treaty with the Negus in January, 1897, and four or five French expeditions were planned for the purpose of opening Abyssinia and the eastern Soudan to French influence and commerce. M. Bonvalot was officially commissioned to investigate the problem of entering the Soudan. Prince Henri d'Orleans undertook a similar mission without official credentials. Max Baveloer was sent out by the French Chamber of Commerce to prepare the way for another party under the Vicomte de Constantin. One of the objects sought by the French is permission to construct a railroad from Djibouti to Harrar. The line is expected to be completed to the Abyssinian town of Antotto before the end of 1899. M. Lagarde, the Governor of Obok, was intrusted with a new diplomatic mission to the Negus. An imposing diplomatic mission was conducted by Rennell Rodd, secretary to the British legation in Egypt, who was dispatched as special envoy, with a numerous staff, to reopen diplomatic relations with the Ethiopian monarch and to acquaint him with the nature and extent of the British claims in Egypt and the regions of the upper Nile, and secure his recognition of British and Egyptian rights over Kordofan and Sennaar and throughout the regions of the White Nile. One of the objects of the mission was to induce King Menelek to retire from territories that he had conquered which formerly belonged to Egypt. A commercial convention formed part of the negotiations, also a proposal for co-operation against the dervishes of the Soudan. Russian expeditions of a semiofficial or patriotic character, though ostensibly religious or scientific, had been numerous in Abyssinia during the nominal Italian protectorate from the time when the Cossack Ashinoff led the way in 1889. The Russian Church has sent missionaries to the country at various times. Lieut. Mashkoff went on a political errand in 1891. In 1895 a party of Abyssinian prelates and princes visited St. Petersburg under the personal conduct of M. Leontieff. Col. Maxinoff visited Menelek at Adis Abeba in the early part of 1897. A new Russian expedition under M. Poliakoff set out from Europe in the beginning of April, 1897. The English expedition, setting out from Zeila, reached Adis Abeba on April 28. An agreement between Great Britain and Abyssinia was signed on May 14, and on the following day the envoy and his suite took their departure. The Emperor Menelek in treating with the English envoy was even less inclined to acknowledge as lying within the British sphere territories formerly conceded to Ethiopia by British diplomacy and others actually occupied by Abyssinian forces than he was to sanction the retention by Italy of the boundaries within the Abyssinian high plateau to which he had provisionally consented in the treaty of Adis Abeba. Kassala itself was formally restored to Ethiopia by the treaty of June 3, 1884, concluded between the Negus Johannes and the Egyptian Government under the auspices of Great Britain. Afterward Great Britain, on March 24, 1891, recognized as Italian the whole Ethiopian Empire, from the river Juba to the Blue Nile, and by a second treaty of April 15, 1891, completed this gift of Abyssinia to Italy, including in the gift the town of Kassala, with the stipulation that it should be retroceded to Egypt. In like manner England, after agreeing with France by the convention of Feb. 8, 1888, to neutralize Harrar, which at that moment was in the actual possession of Abyssinian troops, by a new treaty on May 5, 1894, expressly abandoned Harrar to Italy. Germany also, in the Anglo-German agreement of July 1, 1890, sanctioned the abandonment of Ethiopia and the Galla countries to Italy. Believing that the treaty of Adis Abeba canceled all these former treaties by which European powers disposed of his territory without his knowledge or consent, Menelek was anxious that in coming to a definite boundary agreement with Italy, and in fixing the boundaries between Abyssinia and the Egyptian Soudan, the great powers should ratify the arrangement. While the Negus was willing to concede the provisional boundary formed by the rivers Mareb, Belesa, and Muna as the permanent frontier, the various Ras wanted him to insist on a frontier considerably to the north. Italian Policy.-Major Nerazzini was commissioned to delimit the frontier of the Italian possessions on the line laid down in the treaty of peace. King Menelek endeavored to persuade the Italians to abandon the Mareb boundary and accept a new frontier at the foot of the high plateau. The Government of the Marquis of Rudini decided to retain the positions on the plateau, which, according to expert opinion, could be defended by 5,000 men against an army. After a week's discussion, on May 22 the Italian Chamber passed a vote of confidence in the undefined plans of the Government, rejecting by a majority of 89 a radical proposal in favor of entire abandonment, and by a much larger majority the motion of the Opposition to suspend action until the new limits were fixed at the widest extent allowed by treaty through the delimitation survey. Later in the year the Government decided to appoint a civil governor in the place of Gen. Vigano. Ras Alula before his death, in February, 1897, gave the Italians trouble by his raids upon their territory. On the opposite frontier the dervishes taxed their resources. Their horsemen attacked the Beni Amer tribesmen in Italian territory and drove away their cattle, killing 30 of the Askaris who were sent to repel the raid. A large dervish force left Ghedaref at the beginning of January, and, plundering the Bazas tribe, entered the country of Barias, who fled with their cattle to the hills. The Italians, anticipating an attack on Agordat, concentrated troops on the plain with such rapidity that the dervishes withdrew and intrenched themselves at Amideb. The Italian prisoners released by the Negus began to arrive home in the beginning of January. Toward the end of that month Menelek directed that no more prisoners should be set free until the Italians evacuated the part of Erythrea restored by treaty to Abyssinia. Further convoys of prisoners were sent to Zeila later. The last prisoner to leave Adis Abeba was Gen. Albertone. In the provinces a few Italians still remained in May. Major Nerazzini continued his negotiations with Menelek for a definitive treaty until early autumn, when he returned to Italy for fresh instructions. King Menelek would agree to none of the proposals of the Italian envoy, and promised only that he would grant to Italy a better frontier than that accepted by Count Antonelli but rejected by his Government in 1891. By this Italy would lose the two fertile provinces of Serach and Oguleh-Cusai, as well as the strong Mareb boundary. The boundary that he proposed starts from Tomat, on the Atbara, joins the Mareb at Todluk, follows that river to its confluence with the Mai Ambessa, which it mounts to its source, follows the Mai Feccia down to the upper Mareb, ascends the Mai Raetta, passes south of Gura, Digsa, and Mahio, descends to the plain of Galline Faraone, and runs parallel to the Red Sea at a distance of 60 kilometres from the coast. On the southeastern border it continues at 180 miles from the shore of the Indian Ocean, joining the Juba to the north of Bardera and leaving Luk under the suzerainty of Abyssinia, though it remains an Italian trading center. This frontier was accepted by the Italian Government, with a reserve as to Adí Caje, a post that had been fortified by the Italians at an expense of 3,000,000 francs. The chief points of the negotiations, which were to be brought to a conclusion within a year of the signature of the treaty of Adis Abeba, on Oct. 26, 1896, were the amount of the ransom for the Italian prisoners and the delimitation of the frontier. Menelek abated his claim for ransom from 20,000,000 to 10,000,000 lire, but grew more exacting in regard to boundaries. The Italian Government was not ready to evacuate at once the high plateau, on account of political considerations at home and international complications, and for fear of intertribal conflicts resulting upon the withdrawal of Italian forces. The prospective restoration of Kassala to Egypt, which could be accomplished as soon as the Anglo-Egyptian forces gained possession of Khartoum and Berber, would hasten the development of the ultimate Italian policy in Africa. If the colony could not be made self-supporting and defensible without any further sacrifice of Italian blood or treasure, the Rudini Government would prefer withdrawal from the Abyssinian plateau, from Asmara and Keren, and even from Massowah. The Erythrean budget as prepared and presented to the Chamber on May 18, provided for an expenditure of 19,800,000 lire for 1897. Subsequently the estimate was cut down by the ministry to 8,900,000 lire. In May Signor Rudini induced the Chamber to indorse the possible limitation of the military occupation to Massowah alone and the organization of the rest of the colony, including the high plateau, under tributary native chiefs. Hence Menelek increased his demands and refused the Mareb frontier, which he was willing to concede after the battle of Adowa. Major Nerazzini concluded with Menelek a commercial treaty securing for Italian citizens full freedom of movement and of trade, with protection for merchants and merchandise and most-favored-nation treatment in respect to customs and octroi duties. Both contracting parties bind themselves to promote the opening of routes for the better development of commercial relations between the Italian territories on the Indian Ocean and the south of Abyssinia. The treaty gave to Italy the right to have a permanent representative at the Abyssinian court. Capt. Ciccodicola was appointed to this post, while Senator Bonfadini was made Civil Governor of Erythrea. In August the Italian Government informed the British Government that it was desirous of transferring Kassala to the Anglo-Egyption authorities as soon as possible. Operations in Somaliland.-After the defeat of the Italians in 1896, Ras Makonen, a cousin of King Menelek, and the most powerful of the feudal princes of Abyssinia, established himself in Harrar, of which he was appointed governor, and with his army of 40,000 men extended his conquests over the Somalis, occupying Ogaden, a district lying within the sphere assigned in conventions to Great Britain. The Equatorial Provinces.-Rennell Rodd's mission, so far from obtaining from Menelek an admission that the region of the White Nile was within the Anglo-Egyptian sphere, took back to England the reply that he considered the whole Hinterland as Abyssinian, including the banks of the Nile down to Khartoum and up to the Lake Nyanza, with all the country of the Gallas. He declared, however, that he would not assist the dervishes against the English, and when the Khalifa sent an ambassador later, seeking an alliance, he declined to enter into a league with his hereditary enemies. In Gallaland and Somaliland the English envoy conceded to Abyssinia some of the places reserved to British influence in the Anglo-French agreement of 1891. The Russian Major Leontieff, who obtained from King Menelek the appointment of Governor-General of the Equatorial Provinces of Ethiopia, made arrangements with Prince Henri of Orleans to organize an expedition to take possession of both banks of the Nile up to the borders of the Congo State, in the name of the Emperor of Ethiopia, and thus frustrate the British plan of connecting the East African protectorate with Egypt, and at the same time establish communications through Bahr el Ghazal with the French outposts on the upper Ubangi. French engineers had obtained the right to build a railroad from Jiboutil to Harrar and Adis Abeba. A concession for railroads in Abyssinia was granted to a company formed by Alfred Ilg, a Swiss engineer, and Alfred Chefneux, a French explorer. The French were already erecting for King Menelek a telegraph line over this route. The rival French expedition that went out under M. Bonvalot, with whom Prince Henri of Orleans quarreled at the outset, reached the White Nile first, passing through the Galla country, where the intercession of Menelek secured a good reception for the Frenchmen, who were now led by the Marquis de Bonchamps. The object of this expedition was to establish France solidly on the left bank of the White Nile with the help of an Abyssinian Ras, and afterward support the French on the Ubangi. The sphere of influence claimed by the Emperor Menelek extends from 14° to 2° of north latitude. Starting from the boundary line of Italian Erythrea, the frontier follows the fourteenth parallel to Tomat, on the Atbara, and thence goes straight to the White Nile, leaving to Abyssinia a good part of the island of Meroe, Sennar, and Abu Harraz, on the Blue Nile, and reaching the White Nile a little below Koweh, about 150 kilometres up the river from Khartoum. From this point it ascends the White Nile, leaving the left bank to Abyssinia as far as Lake Albert, whence the frontier follows the second parallel of north latitude eastward to the Juba river, and by this stream follows the Italian frontier of the Somali coast up to the English frontier above the Ogadayn. This new frontier was provisionally accepted by England, which retains on the Gulf of Aden no more than a strip of about 75 kilometres behind Zeila and Berbera. Menelek submitted this series of delimitations to France, Russia, and Turkey for their approval, with the view of settling the definitive boundaries of his empire under the guarantee of Europe. AERIAL NAVIGATION. The introduction of aeroplanes has caused marked advances in aëronautics during the past decade, largely through the experiments of Hiram S. Maxim, of England, Otto Lilienthal, of Prussia, and Samuel P. Langley, of the Smithsonian Institution, Washington, D. C. These three have made extensive and costly experiments, extending over a period of years, and Lilienthal gave his life to the advancement of the science, being killed by a fall from his soaring apparatus Aug. 11, 1896. Other investigators in this field, whose researches have added to our knowledge of the principles of mechanical flight, are Octave Chanute, of Chicago; Arthur Stentzel, of Altona, Prussia; MAXIM'S FLYING MACHINE. MM. Tatin and Richet, of France; Carl E. Myers, of Mohawk, N. Y.; A. M. Herring, Horatio Phillips, and Pilcher, of England; and George Wellner, of Brünn, Austria. All these, except Myers, have made use of some form of arëoplane, imitating the soaring of birds or the suspension of kites. Investigations in kiteflying have aided the aviators, and a description of recent progress in these will be found in the article KITEFLYING in this volume. Maxim was the first to build a machine that actually lifted itself off the ground without external aid or the pull of a bag of gas, and this feat, accomplished July 31, 1894, marked the greatest achievement in aëronautics since the time of the Montgolfiers. The experiments of all the investigators favor aeroplanes slightly concave on the lower side, and they have had to overcome immense difficulties in the way of securing material combining the requisite strength and lightness. Maxim's aeroplanes were stretched on frameworks of steel tubing, stiffened with wire, the material being balloon cloth in two thicknesses. The reason for making the cloth double was that the planes, being large, developed a great tendency of the material to flap and bag, causing a deformation that interfered seriously with the lifting capacity. By using two thicknesses, set slightly apart, and making the lower thickness somewhat porous, while the upper was almost air-tight, it was possible to preserve a flat surface of the lower thickness of cloth, transferring all the flapping to the upper surface, where it causes no serious inconvenience. The propelling machinery was placed on a deck of trussed construction, suspended below a large aëroplane, set at an angle of about 1 to 10, and having other and smaller aeroplanes above and at the sides, set well apart, the object being to prevent their taking the wind from each other. The mechanism was quite large, constituting an air-ship, with 4,000 feet of lifting surface. A steam engine was used for motive power, and the apparatus was run along a light railway track until the speed gave the required lifting power to take it from the ground. Maxim took infinite pains in the construction of engines and boilers of sufficient lightness, and finally settled on a boiler having thin copper water tubes, curved among the flames. Through these he maintained a forced circulation and was able to obtain 800 feet of heating surface with only 34 feet of flame surface. The boiler weighed half a ton, carried 200 pounds of water, and by means of gasoline fuel, with flames 22 inches high, was made to furnish steam enough for the engines, whose efficiency was 364 horse power. The engines were of marvelous construction, and would have served to make Maxim famous had he done nothing else in the line of invention. They weighed less than 2 pounds to the horse power, which is about one thirtieth of the weight of the latest and best marine or stationary steam engines. They were of the double-expansion type, used the steam at 300 to 350 pounds pressure, had a piston speed of 750 feet a minute, and were made throughout of high-grade steel, many of the parts being tempered to increase the tensile strength. These engines drove the screw propellers, which were 174 feet in diameter, with 16 feet pitch. Each engine being separately connected with its propeller, they could be used for steering, as well as driving the machine, by simply running one engine, and consequently its propeller, a little faster than the other. Unfortunately, this flying machine was badly wrecked on the first day of its trial; but as the wreck was caused by the unexpectedly great lifting power developed, causing a bending of the axles of the upper wheels that had been provided to confine the machine so that it could not take any extended flight, and as numerous data were obtained of the details of its operation, the experiment was universally regarded as a success. On the day of trial three runs were made over the track, which was about 1,800 feet long. The first two runs were made at moderate speed, in the endeavor to familiarize the operators with the workings of the mechanism. The third run was made with the steam at 310 pounds. The whole mechanism weighed a little less than 3 tons, and the dynamograph showed that the following lifting powers were exerted: 100 feet, 700 pounds; 200 feet, 1,700 pounds; 300 feet, 3,000 pounds; 400 feet, 3,700 pounds; 500 feet, 3,950 pounds; 600 feet, 5,750 pounds; 700 feet, 6,600 pounds; 800 feet, 6,450 pounds; 900 feet, 6,500 pounds; 1,000 feet, 8,700 pounds. The machine was lifted from the ground after running about 600 feet, and continued to ride against the upper rails until the unexpected lift of 8,700 pounds caused the break-up. Otto Lilienthal was a Prussian engineer, who began experimenting about 1890 with winglike planes, LILIENTHAL'S LAST SOARING APPARATUS. which he carried just below his armpits, and, by taking a swift run from a hilltop against the wind, was able to soar or slide down on the air to a considerable distance. He called his mechanism a soaring apparatus, and by patient trials and experiments developed and improved the structure until it assumed the form here shown. He built about a dozen different types in all, and patented them in many countries, selling some to other investigators and experimenters. Lilienthal constructed a hill on purpose to have one convenient for conducting his experiments. His first apparatus was about 16 yards in extent of surface. He practiced with this, and learned to balance and guide it to a certain extent by the swaying of his body. Later he added a tail or rudder, and in 1895 he built one with two superposed aeroplanes, between which in the rear was hung the rudder. This arrangement gave him a larger area of supporting surface, and he was able to soar higher, and at times to remain stationary in the air. His longest flight was somewhat over 900 feet. He exercised great care and seldom soared more than 25 feet above the ground. He was endeavoring to soar in curves, so as Pilcher, of England, and Mouillard, of Cairo, Egypt, have also built soaring apparatus, on the principles developed by Lilienthal, with devices of their own invention. Both of them have used surfaces as great as 300 feet, but these can be used only in calm weather. A. M. Herring and several others in the United States have also built similar mechanisms or purchased them from Lilienthal for experiments. Octave Chanute, of Chicago, built them in a variety of forms, some having six or eight wings or planes. Samuel P. Langley's experiments began about 1896, with a circular whirling apparatus, having an arm swinging around a circle about 65 feet in diameter, from the end of which he suspended all sorts of weights and planes, and whirled them at different speeds, to study the laws that governed rapid motion through the air. A few years later Horatio Phillips conducted similar experiments in England on a somewhat larger whirling mechanism. He constructed a machine with a series of superposed aeroplanes, the whole weighing 350 pounds, and was able to whirl it around a circular track with very little power. Prof. Langley tried small weights, studying the principles involved, before he tried to build a machine that would fly. He found that a thin brass plate weighing a pound, when hung from a spring at the end of his whirling arm, could be made to reduce its pull or strain on the spring from 1 pound when stationary to an ounce or less when rapidly rotated, and that actually less power was required to rotate and sustain the weight than to sustain it when stationary. His experiments in this line continued until 1889, demonstrating that an engine of 1 horse power could support 200 pounds weight in horizontal flight, by taking advantage of the inertia of the air as a support. Having established the conditions to be met, Prof. Langley set about building a machine, which has been styled an aerodrome. This was completed in November, 1893, but was not sailed with satisfactory success until May 6, 1896, when a successful trip was made over the waters of the Potomac, the place being selected in order that the aerodrome might alight on the water and not damage itself by falling. Prof. LANGLEY'S AERODROME. aeroplanes. to circle in imitation of birds, shortly a, empty float; b, boiler; p, p, propellers; r, rudder; w, w, w, wings or before he received his fatal fall. It was generally thought that his two-plane apparatus was not so safe as the single plane, with which there had been no serious accidents. Of the various sizes made, he preferred those having surfaces of about 100 feet and measuring about 18 feet from tip to tip. He built these of a weight of 50 to 60 pounds, and so constructed that they could be folded up for easy conveyance. Langley speaks of the machine as a great steel kite made to suspend itself in the air by the speed or thrust of its motor instead of a restraining kite string. The great difficulties that he encountered in its construction were sufficient reduction in weight and proper balancing. As originally designed, his aerodrome was to be a mechanical bird of about 25 pounds weight, including a 1-horsepower engine. When the first construction was completed it weighed about 40 pounds, and the motor developed but half a horse power, and this after months of endeavor to secure a sufficiently strong construction with little weight. Subsequent machines were built with engines driven by compressed air and by carbonic-acid gas; but these also had to be abandoned, because it was found impossible to bring the weights of the boilers within the limits. Steam boilers were made in many ways, in the endeavor to secure one light enough and yet large enough to make sufficient steam. At last one was designed which was very wasteful of steam, but which would deliver from 1 to 14 horse power, and which weighed, engine and boiler together, without fuel, 7 pounds. Gasoline vaporized was used for fuel, and about 2 quarts of water supplied the boilers. The main frame is of steel tubing, the entire length 16 feet, the wings measuring 12 feet from tip to tip, and being fixed-that is, not flapping. The total weight is slightly under 30 pounds. The two propellers are each about 4 feet long, and make 800 to 1,300 revolutions a minute. It had to be launched in the face of the wind, and when completed was designed to be shot off with a spring mechanism from the top of a house boat in a dead calm. It could not start itself, because of the initial velocity (about 25 miles an hour) required to sustain it in the air. Two years and a half were occupied from the time the aerodrome was completed until it was made to soar away as designed. First, days were spent waiting for dead calms that never came; then the spring motor proved unsatisfactory, and another launching device had to be contrived and constructed; then, when a launch was actually made, it was found that very nice balancing was necessary to preserve the position in the air. The aerodrome had a way of starting off on an up curve and tumbling over itself, as it were, or of shooting suddenly downward into the water, until it seemed as if it never could be made to sail properly. At last, in May, 1896, one day of trial, at which it was expected that the machine would develop the usual or new eccentricities, the operators were delighted to see it soar away as steadily as a great bird, describing large curves in the air, and after its water supply was exhausted sink gently down on the surface of the Potomac, without the slightest injury. The trial was immediately repeated, with equally satisfactory results. Several subsequent successful trips have been made, the most notable being on Nov. 28, 1896, when the aerodrome sailed three fourths of a mile, at a speed of 30 miles an hour, rising, from a starting point perhaps 15 feet above the water, to an elevation of about 100 feet. The flight is limited by the small amount of water carried. Prof. Langley believes that if a sufficiently light condenser can be added to preserve the water for use over and over, a flight may be sustained for hours. Two French investigators, MM. Tatin and Richet, in 1896, made a test of an air-ship that seems, from the brief description sent out, to be somewhat like Prof. Langley's, but larger. Steam was used as a motive power, the engines being fixed on a car or body made of light pine, braced with steel wires, and sustained by two fixed wings or aeroplanes of 86 square feet surface. The total weight of the machine was 73 pounds. Two oppositely revolved propellers were used, one being placed forward and the other aft. A fixed tail or rudder was employed to steady the flight. The entire apparatus weighed 73 pounds, exclusive of fuel and water, and was propelled, entirely by its own motor, for a distance of 460 feet, measured in a straight line on the ground, the velocity attained being 59 feet a second. Guided by their experience with this machine, they built another in 1897, in which the weak points were improved. This second mechanism soared or flew about 250 feet, when it met with an accident. The majority of recent investigators in this field of research regard stationary or fixed aeroplanes as the best arrangement, rather than flapping or beating wings in imitation of birds. Rudolph Kosch, a follower of Lilienthal in experiments with soaring apparatus, dissents from this opinion, and has constructed an apparatus to demonstrate the truth of his assertion, and also that circular wings are the best form. His mechanism consists of four circular planes or wings, slightly concave beneath, and arranged in pairs, each having a rotary motion RUDOLPH KOSCH'S MECHANISM FOR ILLUSTRATING THE POWER about the upright member, and also an up-and-down motion, communicated by a man working cranks below. The pairs are rotated oppositely. With this apparatus a man of average strength exerted for a short time a lifting strain of 50 pounds, or, to express it technically, with an angle of incidence of 10 and aspeed of 72 rotations a minute, the dynamograph recorded a lift of 50 pounds. The circles of these wings were made of steel tubing, with wire spokes, and the covering was of cambric. Mr. Kosch points out that the circular form, which he was the first to construct, gives more surface for the same weight of frame than is possible with any other construction. The machine illustrated weighed 56 pounds, the planes being 6 feet 4 inches in diameter. His experiments suggest that propellers are best placed side by side, as were Maxim's. Arthur Stentzel, of Altona, Prussia, after some years of experimenting with soaring apparatus, evolved a flying machine in 1896 that bore some resemblance to a gigantic butterfly with an exaggerated tail. The spread of the wings was 21 feet, and the surface 8 yards. Compressed carbonic acid was the motive fluid used in the engine, which gave 3 horse power at a pressure of 9 atmospheres, or 1 horse power with 5 atmospheres. The machine weighed 75 pounds, and in use was suspended from a safety cable, to guide it in its flight and prevent damage by falls. When the wings were flapped with 1 horse power, the machine advanced 10 feet along the cable at each stroke of the wings; with 1 horse power the advance was 13 feet to each stroke, in 13 seconds, the machine being lifted clear of the cable. The machine showed good stability |