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 aeronautics 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.

The

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. propelling machinery was placed on a deck of trussed construction, suspended below a large aeroplane, 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 173 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. the day of trial three runs were made over the track, which was about 1,800 feet long. The first two runs

On

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 to circle in imitation of birds, shortly 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.

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.

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 OF CIRCULAR WINGS.

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 83 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 I 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

in the air, the rudder serving efficiently as a guide. Steel tubes were used for the main parts of the framework, and ribs of bamboo, with rubber

STENTZEL'S FLYING MACHINE.

cloth for the covering. The performance of the machine was so satisfactory to Stentzel that he is now building a larger one, designed to carry a man. This will have about 23 yards of surface, employing a 4-horse-power motor, and is designed to weigh 200 pounds.

Carl E. Myers, of Mohawk, N. Y., patented, April 20, 1897, what he styles a sky cycle or gas kite, this being a balloon of peculiar form shaped so as to split the air in its advance, the motor power being a man centrally suspended, so that he may operate both foot and hand cranks for rotating a propeller placed forward. This propeller is of most ingenious construction, having an area of 15 feet, but weighing only 2 pounds. It is made of a light steel frame, on which a cloth covering is twisted heliacally, so that it not only serves as a surface, but keeps the parts of the frame in position. Myers began his experiments by firing projectiles of all sorts and shapes from a spring gun of known force, thus learning the form best adapted to travel against the wind. He claims to have arrived at a formula that enables him to produce the very best form for the purpose; and though he has constructed the gas bags of his sky cycles in different forms, yet by

MYERS'S SKY CYCLE.

following his formula he always secures a shape that makes good headway against the wind. He constructs his apparatus so that it is slightly heavier

than the air, depending on the propeller to draw it upward. He evidently uses the lower surface of his gas bag as an aeroplane. Several successful exhibitions have been given with his apparatus.

Dr. Louis Martin, a professor in the University of Kolozsvar, Hungary, in a lecture at Buda-Pesth in 1893, exhibited an apparatus of rotating paddles operated from an eccentric, so that they beat down on one side, and were feathered on the rise. The pressure exerted by this mechanism was so satisfactory that the Hungarian Government has made an appropriation to enable him to continue his experiments, with a view of adapting the principle to a flying machine.

A. M. Herring, of the United States, has experimented with a great variety of aeronautical mechanisms, mostly with small models. He has made numerous mechanical birds, driven by motors of twisted rubber that rotated propellers as it untwisted, and with these he has obtained flights of five to seven seconds, with distances of 80 to 135 feet. They can be made to fly successfully in winds of not more than 7 miles an hour. One of his larger models is shown here, this weighing 5 pounds and carrying a condensing engine of two fifths horse power. It presented a surface of 14 square feet, and, with no aid in starting, flew 240 feet, and might have done better had not the boiler burst early in its career.

There is an aeronautical society in London and one in Boston, the latter growing out of an aëronautical conference, which was called in Chicago in

HERRING'S FLYING MACHINE.

66

1893. The society publishes an Annual," the first issue of which appeared in 1895. A monthly publication devoted to the subject is also issued in New York city by A. M. Forney. Recent literature on aeronautics includes an exhaustive treatise by Octave Chanute, in which he elaborates and explains all the modern theories and principles developed, and describes most of the flying machines exploited within the past fifty years. Samuel P. Langley has written articles concerning the principles and conclusions derived from his investigations, and Hiram Maxim and Otto Lilienthal have also written much on the subject. Maxim, in writing on "Natural and Artificial Flight," says: "I have found that if one only desires to lift a large load in proportion to the area, the planes may be made very hollow on the underneath side; but when one considers the lift in terms of screw thrust, I find it advisable that the planes should be as thin as possible and the under side nearly flat." Octave Chanute says of the conditions of sailing flight: "1. There must be wind, although it may be light. 2. No flapping whatever is needed when under way. 3. The bird

must have a peculiar conformation. 4. The bird needs a certain mass or weight." Prof. Langley calls attention to the fact that birds soar in up currents of air, and by taking advantage of increased wind speed at the higher elevations. He also advises the use of the propeller rather than flapping wings. A. M. Herring is hopeful of the future of flying machines, but not optimistic. He says they never will carry freight, and that the machine to carry two persons successfully "is an invention of the relatively distant future."

Through the efforts of various aviators and investigators in aëronautics, Mr. Lodge, of Massachusetts, introduced into the United States Senate, Dec. 4, 1895, a bill to secure aërial navigation. It provided for the giving of $100,000 from the United States Treasury to the person who, prior to Jan. 1, 1901, should construct an apparatus carrying 400 pounds through the air, without the aid of gas, at a speed of 30 miles an hour. and having its power wholly within itself. A second clause provided a gift of $25,000 to the person who, before Jan. 1, 1900, should demonstrate the practicability of safely navigating the air in free flight, for a mile or more, without gas. This bill still remains with the Committee on Interstate Commerce, to which it was referred.

AFGHANISTAN, a monarchy in central Asia, lying between Russian Turkestan and British India. The Ameer is Abdurrahman Khan, who was installed in July, 1880, while the British occupied Cabul, the capital, having expelled Shere Ali's son, Yakub Khan. The Indian Government has since paid an annual subsidy of 1,200,000 rupees per annum, increased in 1893 to 1,800,000 rupees, to enable Abdurrahman to consolidate his power and preserve a strong, united, and independent Afghanistan as a buffer state between the Russian dominions and India. The military forces of the Ameer consist of the feudal militia and the regular army, said to number 20,000. The artillery has 76 modern guns. In the arsenal at Cabul are manufactured gunpowder, cartridges, rifles, and cannon by the aid of machinery under the superintendence of Englishmen. The infantry of the feudal army have received a permanent organization. The cavalry consists of the retainers and vassals of the chiefs. In 1896 Abdurrahman Khan attempted to introduce universal conscription, and ordered the enrollment of one man in every seven, but the objections of the people induced him to defer the realization of his project. The arsenals contain breech-loading rifles enough to equip an army of 50,000 men, which is said to be the war strength of the Ameer's army.

The boundaries between Afghanistan and the Russian territory and dependent khanates have been at various times a subject of negotiations between the governments of Great Britain and Russia. In 1895 the last portion of this line, that which runs through the Pamirs, was finally delimited. The line follows the Amu Daria or Oxus river up to the confluence of the Murghab and the Panjah, and then this latter, the southern branch, up to its source in Victoria lake, from which it runs eastward to a fixed point near one of the peaks of the Sarikol range. This delimitation gives to Russia the territories of Darwaz, Roshan, and Shighnan, which Afghanistan had occupied while the question as to which was the principal branch of the Oxus, and consequently the conventional boundary, was being discussed between the British and Russian governments. In the west the boundary, leaving the Oxus at Khamiab, runs in a southwesterly direction to Zulfikar, on the Heri Rud, thence southward to the peak of Kuh Malik-i-Siyah, southwest of the Helmand river, and from there in a general eastward direction to the Kwajah Amran range. Sir

Mortimer Durand arranged with the Ameer in 1893 the basis of a boundary delimitation between Afghanistan and British India, which has since been carried out by a joint commission, with the exception of the stretch between the Khaibar pass and Asmar. By this agreement Chitral, Bajaur, Swat, and Chilas fall within the British sphere, while Afghanistan retains Asmar and the Kunar valley as far as Chanak, also the Birmal tract. The demarcation included Kafiristan in the Ameer's dominions, and when the people of this district, who differ from the neighboring Afghans in race, customs, and religion, and have always been at feud with them, refused to acknowledge his sovereignty, Gholam Haider with an Afghan army reduced them to submission.

Afghanistan is divided into the four provinces of Cabul, Herat, Turkestan, and Candahar, over each of which is a hakim or governor, and the recently subjugated district of Badakshan, with its dependencies. Afghans and Pathans form the bulk of the population, but with them are mingled the descendants of the former Tartar and Persian conquerors and the various armies that have invaded India through Afghanistan. The Ghilzai, Duranis, Aimaks, Uzbegs, and the Tajiks are Sunnite Mohammedans, while the Kizilbashis and most of the Hazaras are Shiites. The Tajiks, who are of Iranian descent, live in the towns and are scattered among the other tribes, carrying on industrial, commercial, and agricultural pursuits. The Aimaks and Hazaras, inhabiting the Paropamisus mountains in the north, have Tartar features and are supposed to be descendants of colonies left by Gengis Khan. The total population of Afghanistan is about 4,000,000. The Ameer's revenue is derived from the tithes of agricultural produce, increased to as much as a third of the crop on irrigated lands.

The Afghans raise usually two crops a year, one of wheat, barley, or legumes in the spring, and one of rice, millet, panicum, or corn in the autumn. Afghanistan abounds in fruits, such as apples, pears, quinces, almonds, peaches, apricots, plums, cherries, pomegranates, mulberries, grapes, and figs, which form the main part of the food of a large section of the population, and in a preserved state are exported to India and other countries. The castor-oil, madder, and asafoetida plants are abundant in the wild condition. Asafoetida is exported in great quantities to India. Lead, gold, iron, copper, and precious stones are found. Silk, felt, carpets, and rosaries are made by the people and exported. Horses, spices, nuts, and sheepskin garments are other exports. The principal articles of import are China tea, cotton goods, indigo, and

sugar.

The Mittai Question.-Under the terms of the Durand convention of 1893 provision was made for demarcating the respective spheres of the Government of India and the Ameer. The object aimed at was to lay down definitely the law under which powers of sole control over particular tribes or clans were to be exercised on either side. The country dealt with was a long, narrow strip lying for 1,200 miles between British India and Afghanistan proper. The demarcation had been carried out by various commissions from Chitral and the Kafiristan border to the Helmand river before the beginning of 1897 with the important exception of the tract lying between the Kunar and Cabul rivers, from the Nawar Kotal to the neighborhood of Landi Kotal, in the Khaibar. This is the country inhabited by the large tribe of the Mohmands, which has figured prominently in the politics of the Indian border for many years. There were peculiar difficulties to be faced in dealing with this people, and by common consent the demarcation of the boundary of sole control in