formation, and as solving no real difficulty, as it is little more than a balloon, after all. More is owing to one man, whose last experiment ended in a pitiful failure, than people generally are inclined to think. Samuel Pierpont Langley was a man who made a study of the principles involved in the aeroplane style of flying for a long period before he attempted to build a man-carrying apparatus. The fact that his last machine collapsed and fell into the river upon which it was being tried, is attributed by many to

PAIR OF EXPERIMENTAL LINEN WINGS.

improper launching, and it is believed that if funds had not been lacking for the renewal of Langley's experiments, he would have demonstrated that his device was a success. Two models made on the same plan as the larger machine were entirely successful, before the final experiment was made and great hopes were based upon flights made by them. But nothing has been done to carry out Langley's plans. As a result of his study it was discovered that an aeroplane driven through the air requires less power

for its driving as its speed increases, which is a principle exactly opposed to any governing a surface vehicle. And it shows that a power of which we have been quite ignorant exists in the air.

Alexander Graham Bell, of telephone fame, has recently been experimenting with a curious kite, which is built upon lines wholly different from those adopted by any other inventor. He has built up a great man-carrying device, which, when in flight, looks more like a flock of small birds engaged in concerted effort to carry a general burden, than like a single. kite. It is made up of hundreds of tetrahedral cells, each a kite in itself, which acts like an independent bird, so far as automatic balance is concerned, but which bears its share in lifting the weight of the whole. The idea has not yet been applied to a motor-driven machine, but it seems to hold great promise.

If anything like an attempt were made to give the history of development of the two forms of flying-machine most in use, many other names would of necessity be included in the list of those who have contributed to the knowledge we now

possess. Hiram Maxim's great aeroplane which failed, not because of wrong principles adopted, but because of the failure of materials, gave much to the men who succeeded him in this department of experiment, and many another has failed, only to see his ideas forward the general progress by another step. Of course, many freaks of inventiveness have appeared, some of which yet contain the germ of an idea later developed by some saner mind than that of the inventor. Some of the records made have teen remarkable, but the tale is too long to be included here. Results as a whole have lifted the whole question of flying out of the dream-class, certainly.

That the first really successful flyingmachines should be applied to military uses is natural. The probability that they will take a conspicuous place in any important future campaigning, is a foregone conclusion. International agreements will never prevent their use as engines of destruction against armies and

UT from the beach, at East Seventy third street, Chicago, there rises up over the waters of Lake Michigan a system of wires and supports that suggests an electric car system. For two or more miles the wires reach, curving apparently toward the middle in a great undulating sweep that is due chiefly to the illusive effects of distance. All the past summer they have been there, the wonder and speculation of visitors to Jackson Park and the South Shore Shore Country Club.

This thing that has attracted so much attention is, indeed, a trolley system-not of the electric type, nor for the purpose of hauling cars, or boats even, but to transport trains of buckets laden with blastshattered rock. A hundred feet or more below the bottom of the lake this rock is being torn from its bed, and this skeleton against the skyline is a part of the machinery being employed to extend the system of great tunnels upon which Chicago is dependent for her water supply.

The Stockyards district, and, in fact, all Southwestern Chicago, has never been adequately supplied with water. Three firms of

contractors now have gangs of men at work night and day hastening to make good the want. A huge sixteenfoot tunnel, to act as conduit, is piercing the bowels of the earth. The contractors having the work in charge are operating separately, and when their work is completed, the several sections will be united in one great tube. While two of the contractors are working

up, the contractor invited a party of some fifty people to enjoy a ride in specially constructed passenger "cars." They experienced a rough but very exciting and. exhilarating passage as they bobbed along thirty feet above the grey rolling

waves.

This trolley system consists of a very stout cable that operates on the same principle as the endless chain. The buckets come dancing shoreward on the upper wire and return to the crib, as the foundation of steel and concrete and

the accumulation of debris, after several blasts is so great that this part of the work must necessarily be suspended till the shaft can be cleared and the earth and broken stone raised to the surface. The fumes of dynamite are especially pungent and penetrating. Workmen describe the sensation of inhaling them as most overpowering. As one workman said, "It is as though your lungs were turned to rubber." The limbs of the sufferer become numb and flashes of red puzzle the vision.