Science for Beginners: An Introduction to the Method and Matter of Science

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World Book Company, 1918 - Science - 388 pages
 

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Page 298 - And when neither sun nor stars in many days appeared, and no small tempest lay on us, all hope that we should be saved was then taken away.
Page 311 - Rub a dry glass tube or rod with silk and present it to the pith ball. Two things will happen to the pith ball: at first it will be attracted; but presently the ball will fly away, and then the excited glass will repel the ball. (2) Repeat the same test with the sealing wax rubbed with the flannel. The pith ball is affected in exactly the same way. The excited glass or wax causes the ball to become charged with electricity, and then the ball is repelled by the rod or wax. As a magnet will cause a...
Page 255 - The evaporation of the water takes up heat, and (3) If heat is required, must the object which furnishes the heat become colder? (4) Does salt water freeze at a lower temperature than water that contains no salt? Exercise 7. Place a small, tightly corked vial of sweetened cream (water may be used for a " make believe " sweetened cream) in the midst of the dissolving ice and salt. What happens? What would you have if you should do this on a large scale ? If you should find the vial broken, how would...
Page 348 - A tool is but the extension of a man's hand, and a machine is but a complex tool. And he that invents a machine augments the power of a man and the well-being of mankind.
Page 98 - The wood of matches is now often " fireproofed " by impregnating* it with certain chemicals. Sodium phosphate or alum may be used for this purpose. CARBON AND ITS COMPOUNDS IN a former chapter we learned that oxygen is the most abundant element in the crust of the earth and therefore the greatest in amount in the soil. If we turn our attention to the things that live and grow in this soil, we -shall find that in them by far the most abundant element is carbon. Carbon is extremely important, because...
Page 110 - ... chemistry. Some one has said that the state of civilization at which a nation has arrived may be measured by the amount of soap consumed. In England there are manufactured over 50 pounds per year for each man, woman, and child. In America the rate is very nearly as high. Before any conclusion is reached by putting these statements together, it should be noted that England sends a large amount of her soap to America, and that Germany, France, and Holland do the same. History of soap and soap making....
Page 26 - I am the daughter of earth and water, And the nursling of the sky ; I pass through the pores of ocean and shores ; I change, but I cannot die...
Page 176 - Cooking starchy foods. Raw starch is not easily digested, and hence potatoes and other vegetables and green fruits should be thoroughly cooked. In ripe fruits most of the starch has been changed to sugar, which, because it is readily soluble, is easily digested without cooking. A mealy boiled potato is, in fact, near akin to a lump of sugar; for the potato, like all forms of starchy food, must be turned into a kind of sugar before it can be absorbed into the system. Color of the potato. Another important...
Page 286 - Be sure sometime to visit a river, lake, or pond, and perform the same experiment under much more favorable conditions. If you have had any experience with water, you know that it is difficult to tell exactly where an object is when it is under water. Only an experienced person can spear a fish, and a pond is always deeper than it looks. Does something happen to the light as it comes from beneath the water to our eyes? Let us try some other experiments. Exercise 8. Look obliquely into a pail of water...
Page 363 - ... point and gradually thickening so that we shall have the mechanical advantage of their pushing forward a considerable distance while they exert a side force through only a small distance. The screw. The screw is a combination of the lever and the inclined plane. In the jackscrew (Fig. 231), the handle by which the screw is turned is the lever, and the threads of the screw are the inclined plane which the weight FIG.

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