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New Marvels in Physics

By Ben Winslow

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HAT the average student knows correctly after his first quarter in the study of physics, would make very dry reading; but what he knows incorrectly is extremely interesting. Probably not more than one student out of twenty, when he passes into the preliminary study of physics, escapes the danger of too little knowledge. He gains but a tering of the subject; learns a few primary principles that are new and strange to him; and straightway falls into the belief that his knowledge is equal to any occasion. Even before he has fairly entered upon the elementary stages of the study, he begins to put his new knowledge to work. To what extent he can go wrong, is shown by the following specimens of examination answers. These answers were taken from fifty or more examination papers written by first year students, on acoustics, light, and heat. Of

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course, no one paper contained all the blunders; and in fact, many of the papers were practically perfect.

Q. Why do the inhabitants of cold climates eat fat? How would you find, experimentally, the relative quantities of heat given off when equal weights of sulphur, phosphorus, and carbon are thoroughly burned?

A.-An inhabitant of cold climates eats fat principally because he can't get no lean, also because he wants to raise its temperature. But if equal weights of sulphur, phosphoorus, and carbon are burned in his neighborhood, he will give off eating quite so much. The relative quantities of eat given off will depend upon how much sulphur etc. is burnt and how near it is burned to him. If I knew these facts, it would be an easy sum to find the answer.

Q.-An iceberg floats with one million tons of ice above the water line; how many tons are below the water line?

A. The iceberg floats on top because it is lighter, hence no tons are below the water line. Another reason is that an

iceberg cannot exceed one million tons in weight; hence if this much is above water, none is below. Ice is exceptional to all other bodies except bismuth. All other bodies have one thousand and

Q-What are the conditions favorable ninety feet below the surface and two for the formation of dew?

A.-A body of gas as it ascends, expands, cools, and deposits moisture; so if you walk up hill the body of gas inside you expands, gives its heat to you, and deposits its moisture in the form of dew or common swet. Hense these are the favorable conditions; moreover, it explains why you get warm by ascending a hill, in opposition to the well-known law of the conservation of energy.

feet extra for every degree centigrade. If it were not for this, all fish would die,

P. S. When I say one thousand and ninety feet, I mean one thousand and ninety feet per second.

Q. How has the velocity of light been measured?

A. An atheistic scientist (falsely 50called) tried experiments on the staellites of Jupiter. He found that he could delay the eclipse sixteen minutes by

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going to the other side of the earths orbit; in fact, he found he could make the eclipse happen when he liked by simply shifting his position. Finding that credit was given him for determining the velocity of light, by this means, he repeated it so often that the calendar began to get seriously wrong and there were riots, and Pope Gregory had to set things right.

Q.-How would you disprove, experimentally, the assertion that white light passing through a piece of colored glass acquires color from the glass? What is it that really happens?

A. To disprove the assertion that "white light passing through a piece of glass acquires color from the glass," I would ask the gentleman to observe that the glass has just as much color after the light has gone through as it had before. That is what really would happen.

Q.-A hollow india rubber ball full of air is suspended on one arm of a balance and weighed in the air. The whole is then covered by the receiver of an airpump. Explain what will happen as the air in the receiver is exhausted.

A. The ball would expand and entirely fill the vessel, driving out all before it. The balance being of greater density than the rest would be the last to go, but in the end its inertia would be overcome and all would be expelled, and there

would be a perfect vacuum. The ball would then bust, but you would not be aware of the fact on account of the loudness of a sound varying with the density of the place in which it was generated, and not on that on which it is heard.

Q.-Why do water pipes burst in cold weather?

A.-People who have not studied. acoustice think that Thor burst the pipes, but we know that it is nothing of the kind for Proffessor Tyndall has burst the mythologies and has tought us that it is the natural behavior of water (and bismuth) without which all fish would die and the earth would be in an iron grip.

Q.-What is the difference between a "real" and a "virtual" image? Give a drawing showing the formation of one of each kind.

A. You see a real image every morning when you shave. You do not see a virtual image at all. The only people who see virtual images are those who are not quite right. Vertual images are those things which do not exist. I cannot give you a reliable drawing of a virtual image, because I never saw one.

It is interesting to analyze these answers of blundering students, and endeavor to discover by what mental process they arrived at their conclusions.

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On the shores of the lake of the same name, in northern Ontario.

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World's New Treasure-Box

By O. J. Stevenson

NE of the most interesting places in America is the Cobalt mining district in northern Ontario interesting on account of the wonderful richness of its mineral wealth, as well as the peculiarly rapid growth of Cobalt and the adjacent mining towns.

ONE OF THE ORIGINAL HOUSES AT COBALT.

The little town from which the region is named, is not yet two years old, and yet it contains, besides its transient population, some two or three thousand inhabitants, and is, to say the least, unique in its appearance-a city of shacks, huts, and tents mingled in delightful confusion, with here and there a sprinkling of modern houses, theaters, banks, and hotels, to give it an up-to-date appearance, the sign of civilization in the wilderness.

To reach Cobalt, on leaving North Bay, a junction point of the Grand Trunk and Canadian Pacific railroads, on the northern shore of Lake Nipissing. you pass through a hundred miles and more of wilderness, forest, rock, lake, and stream, with nowhere a clearing, and seldom a human habitation. In the fall

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of 1904, a Frenchman named La Rose, working on the new railway being opened through to the rich farm lands beyond, came upon a vein of silver in a railway cut at the upper end of Cobalt lake. The story goes that he stubbed his toe on the rock, and looking at the spot noticed that it was different from the surrounding rock. La Rose, however, knew little of the mining laws or of the real value of his discovery, and sold his rights in the newly discovered mine for $30,000. The property is the famous La Rose or Timinons mine, and is worth millions.

In less than a year, the land within a radius of three or four miles of Cobalt lake was taken up, and many new mines were discovered. Before the end of the present season, and less than two years after the first discovery, upwards of fifty mines will be shipping ore from Cobalt. So far, some three million dollars' worth of ore has been shipped.

One of the peculiar things about the Cobalt country is that before the final discovery, prospectors had been over and over the ground, had camped time and again on the shores of Cobalt lake, but had never even suspected the existence of the richest silver mines in Americauncounted fortune within their grasp.

SLABS OF SILVER FROM TRETHEWEY MINE. Slab back of hammer weighs 79 lbs., worth $491. Analysis-66.67 per cent silver, 2.15 cobalt, .41 nickel, 1.60 iron, 7.03 arsenic, 9.67 antimony, .22 sulphur, 6.72 calcium carbonate, 1.23 magnesium carbonate, 3.29 insoluble.

And yet this is not so strange after all, when we consider the peculiar character of the mines. The silver is found only in narrow veins, generally not more than three or four inches wide, and showing frequently at the surface only a narrow line of silver, perhaps not a quarter of an inch wide. Even in the richest mining properties now in operation, some of the best veins have been walked over day after day by proprietors and workmen. alike, before being discovered. In the

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A BACK STREET IN COBALT, LEADING TO THE FRENCH QUARTER

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