The I WAVED MY HAT IN DELIGHT; THE EXPERIMENT It seemed to me that even the dog, "Daisy," appreciated the "magic." EVERY one knows that water flows downward. in which the arms are of equal length, is filled with water, and each end of the pipe is put into a separate vessel full of water, "the downward pull," or weight, of the liquid in each of the two arms will balance the other, and, if the water is at the same level in the two vessels, it will remain at that level in both vessels. But if the level of the water in one vessel is lower than in the other, since the two vessels are connected with a pipe full of water, the water will run down from the higher level to the lower. This constitutes what is called a siphon. A siphon itself has no more magic about it than a pencil has when it falls, or than any other similar phenomenon in nature, yet some of the siphon's manifestations seem to be not only magical, but almost incredible. "I POURED IN WATER BY THE AID OF A FUNNEL UNTIL THE PIPE WAS FULL." תי. I remember that in my early boyhood I took advantage of this principle of the siphon, and made experiments. Near my home was a well from which water was drawn by a bucket, and poured into a big tub from which the cattle drank. One day several of the workmen on the farm were gathered around this well. On the ground were several lengths of pipe that had been taken from a disused pipe-line between a spring in the distant pasture and the barn-yard. The action of the siphon had always appealed to me, and I quietly decided that I would play the magician and entertain these men with an exhibition of the siphon in action. From the discarded pipe I took a section about fifty feet in length, and A SLANTING SIPHON CONNECTING TUMBLERS. arm of the pipe near the ground several feet away. And when I gave the order: "Remove thumbs!" the water began to flow in a steady stream, and continued to flow as long as there was water in the tub. I must confess that, even to me, it seemed almost like magic, when I realized that the water was flowing upward for almost twenty feet into the pipe, and doing it without any apparent cause. Of course our young people understand that it was the forcible downward "pulling" of the water in the longer arm of the pipe that was stronger than the weight of the water flowing upward in with the assistance of the men, who wondered "what the boy was up to now," I bent it into a curve so that the shorter branch was about twenty feet in length and the longer branch thirty feet. Holding the curved pipe in a horizontal position, I poured in water by the aid of a funnel until the pipe was full. Then I instructed a man to hold his thumb over one end of the pipe, and another man to hold his thumb over the other end. This pipe, thus kept filled with water, had all its parts in nearly the same level, because the curve was held horizontally. We then lifted the curved part in the air, and placed the shorter end in the tub of water. The ground about the tub sloped down A VERTICAL SIPHON CONNECTING BOTTLES. the shorter section, and that it was this continuous downward "pull" that resulted in the contin reason-both depending upon the fact that water can be raised by suction as long as its weight is less than the force of atmospheric pressure. Our young folks may easily construct siphons in any form that they see fit, by using strong rubber hose, or small glass tubing, which may be easily bent into any desired shape by the aid of a gas or alcohol flame. The accompanying illustration shows a boy with a siphon, made of a series of glass tubes connected by pieces of rubber hose, that is only two inches lower at one end than at the other, and yet is raising the water some six feet above, and around, his head. The water will flow from one tumbler into the other, though the higher tumbler be raised, as in the illustration, only two inches (or even less) above the lower one, and the flow may be reversed by lowering the emptied tumbler and raising the one that has been filled. Thus the water can be made to flow back and forth, at first upward, then through the horizontal pipe above the boy's head, and down on the other side. All that is required is that the flow of the water be started by suction, and then it will continue as long as there is water in the higher vessel. In all these forms of the siphon it is necessary to start the flow every time that the siphon is used. In the pipe at the well, I started it, as explained, by filling the pipe with water; in the piping over the boy's head we started it by suction; that is, we drew the air from the tube, and the pressure of the atmosphere on the water forced the water into the siphon until it was filled, when the downward pull of the liquid in the long THE LONGER AND HEAVIER COLUMN OF WATER IS "PULLING" UP THE SHORTER COLUMN AS THE HEAVIER LEAD-PENCIL IS PULLING UP THE SHORTER PENCIL. uous flow. The upward flow of the water in the shorter arm only depended upon the atmospheric pressure of the water in the tub, because the flow in the longer section tended to make a vacuum in the curve; but water was constantly driven in by the atmospheric pressure to prevent the formation of a vacuum. This siphon at the well tub is illustrated in the heading to this article, and is also shown on a smaller scale by the two tumblers with the curved glass tube between them. Such a siphon will "pull" water over an elevation about thirty-three feet in height. The atmospheric pressure is not great enough to lift it higher than this to supply a vacuum. It will raise water to the curve as high as a suction-pump will lift it, and for the same CONNECTING TWO AQUARIA BY THE arm started the flow, which continued as long as there was any water to pull and to be pulled. It required little force to pull the water around the curve by suction at the end of the lower pipe. refuse or debris from an aquarium, or for many other useful purposes. I recently had occasion to connect together a series of aquaria, each with a glass bottom. It was impossible for me to bore holes in the glass, so I was necessarily forced to use the siphon; but a difficulty arose. If the siphon should fail to carry out the water as fast as it ran in, the aquaria would overflow; and if it should carry the water out faster than it came in, the aquaria would soon be empty and the siphon would no longer act, because the siphon could not fill itself. To overcome all this I devised a form of siphon with upturned ends that will, after stopping, start into action without any aid. In the books of physics that I have examined I do not find this siphon mentioned. It is a useful form because, when a series of vessels are connected by it, the siphon will regulate itself, and will keep the water always at the same level. Adjustment is made by the length of the last upward curve of the pipe. The illustration shows the series of aquaria in which the water is kept to within an inch of the top of each. These siphons, unlike the simpler ones mentioned in the books, may be lifted entirely out of the water, and when replaced will at once, or "voluntarily," as one may express it, resume their work, because they keep full of water. A series of tubs might be thus arranged for fish, for watering cattle, or for other useful and labor-saving purposes. These suggestions may enable our young folks to make some interesting experiments in the use of the siphon. A PHOTOGRAPH OF A CROW BY HIMSELF MR. H. R. CAREY invented a device by which a crow took a photograph of himself when he pecked the bait, which was connected with a string that operated the shutter of the camera. THE WATER RISES SEVERAL FEET FROM THE HIGHER Siphons are used to draw off the liquid from a vessel containing it, especially where there is sediment at the bottom and we desire to take off the clear liquid without disturbing the sediment; or the reverse may be done, and we may remove the sediment with little of the liquid. Thus the siphon may be employed to remove the objectionable By courtesy of "Bird-Lore." THE CROW'S SELF-PHOTOGRAPH. THE SEA-GOING RAILROAD THE railroad from the southeastern end of Florida to Key West is now completed and is open to the public. It is, indeed, a remarkable engineer five miles are over the water, and a considerable portion is over the sea itself. The series of islands known as the Florida Keys may be called a series of stepping-stones leading into the ocean. They extend between the Florida peninsula and Key West in the form of a curve, the channels that separate them varying in width from a few hundred feet to several miles. Between the nearest key and the mainland is a stretch of prairie or marsh with insufficient water to float dredges, and not enough material within reach for wheelbarrow work. This condition made it necessary to dig channels on each side of the road-bed to accommodate the dredges used in building this section of the em A SECTION OF THE RAILROAD EXTENDING ing feat because it is really a railroad over the sea. This is not a figure of speech, for, of the one hundred and twenty-eight miles of track between Homestead and Key West, fully seventy ON THE VIADUCT OF HUGE ARCHES. bankment. Channels were first dug so as to provide a depth of two and one half feet of water. Up these the two dredges slowly made their way, each digging its own channel deeper. They piled up between them the material thus dredged out, and with it formed the road-bed. The progress of the dredges was hampered and delayed in many places by the rocks, which came so near the surface as to necessitate the construction of locks to float the dredges over them. Nearly thirty islands are utilized for short stretches of the construction, the longest being sixteen miles on Key Largo. More than fifty miles of rock and of earth embankment had to be put in where the water is shallow, but, where the water is deeper and the openings exposed to storms by breaks in the outer reef, concrete viaducts were |