CLASS ACTIVITIES 1. Give a clear, connected account of how men made heat work; tell first the plan for your talk. 2. Name industries in your community which could not be carried on as they now are if the workmen had to depend solely on their own strength. 3. What industries in your community make use of the horse as a source of power? Name industries which use wind or water. Which industries use electricity? 4. Read the paragraph which tells what man had to invent before he was able to use any source of power except his own physical strength. 5. In what important respect was Watt's steam engine a great improvement over all preceding engines? 6. Make a list of present-day industries which depend on the steam engine. Which plays the more important part in your community— steam or electricity? 7. Special report for a volunteer: Tell about the Industrial Revolution and the changes which took place after the invention of laborsaving machinery. (H. C. Hill's Community Life and Civic Problems, 344-350.) 8. Volunteer work; a. Explain, with blackboard drawings, how a modern steam engine works. b. Explain how a gas engine works. c. Find how much heat is wasted in the best steam engines and locomotives of to-day. d. Tell how an electric dynamo works. 9. What is the chief difference between this selection and the following poem, "The Song of Steam"? ADDITIONAL READINGS. 1. "The Story of the Steam Age," F. L. Darrow, Boys' Own Book of Inventions, 194-211. 2. "Stephenson and the Locomotive," R. Holland, Historic Inventions. 3. "The Steam Engine," A. Williams, How It Works, 13-43. 4. “The Internal-Combustion Engine,” ibid., 87–111. 5. “Coal - Ally of American Industry," W. J. Showalter, in National Geographic Magazine, 34: 407-434. 6. "Steam in Captivity," H. Thompson, Age of Invention, 53-83. 7. "The Fathers of Electricity," ibid., 194–219. 8. “Fire-making," F. Starr, Some First Steps in Human Progress, 13-29. 9. "The Fire Spirit," H. M. Burr, Around the Fire, 3-18. 10. "How Man Has Harnessed Power and Used It to Drive Machines," L. C. Marshall, Story of Human Progress, 125–144. 6. THE SONG OF STEAM GEORGE WASHINGTON CUTTER Harness me down with your iron bands, For I scorn the strength of your puy hands How I laughed as I lay concealed from sight At the childish boasts of human might, When I saw an army upon the land, Or waiting the wayward breeze; With the toil that he daily bore, As he feebly turned the tardy wheel, Or tugged at the weary oar; When I measured the panting courser's speed, The flight of the carrier dove, As they bore the law a king decreed, Or the lines of impatient love, I could but think how the world would feel, When I should be bound to the rushing keel, Ha ha ha! they found me at last, They invited me forth at length, And I rushed to my throne with a thunder blast, Oh, then ye saw a wondrous change In the darksome depths of the fathomless mine Where the rocks ne'er saw the sun's decline I blow the bellows, I forge the steel, I hammer the ore and turn the wheel Where my arms of strength are made; And all my doings I put into print On every Saturday eve. I've no muscles to weary, no brains to decay. And soon I intend you may go and play, But harness me down with your iron bands. For I scorn the strength of your puny hands CLASS ACTIVITIES 1. Why does the poet use the same four lines to begin and to end the poem? 2. Explain the chief difference between "The Song of Steam" and "How Men Made Heat Work." How are the selections alike? 3. What is needed in order to bind steam to a keel or to bind it to a car? 4. Name inventions using steam for power which have altered the conditions pictured in the second and third stanzas. 5. How does steam perform the various feats mentioned in the fifth and sixth stanzas? Name the different inventions through which these feats are made possible. 6. For a volunteer: Write a poem entitled "The Song of Electricity." 7. MARVELS OF CHEMISTRY IN EVERYDAY LIFE MARSTON TAYLOR BOGERT This selection is made up of parts which fit together like the parts of a hand. In this diagram the palm of the hand. represents a general statement or truth, and the fingers represent illustrations, or proofs, of the general statement or truth. What idea from this selection would you put in the palm as the general statement or truth and what would you place on the fingers as illustrations, or proofs, of the general statement or truth? Practically everything we eat, taste, wear, smell, and see has resulted in some way from the discoveries of chemists. The story of chemistry is like an endless chain — it might begin anywhere, and need never end. Just now you were looking out of the window. That glass is a product of chemistry. Glass is made of soda, lime, and sand. A mixture of these substances is melted down to a bright-red heat. A big molten ball of it is then gathered on the end of a blowpipe. Air is forced through the pipe, and the ball becomes a bulb, the bulb becomes a long cylinder. At the right temperature the cylinder is laid on a table and slit. The cylinder flattens out. That is window glass. In the hall door of your home or in your office there is a pane of plate glass. This is made by casting the molten glass. It is first pressed as smooth as possible, then ground still smoother, then polished. Plate glass is a product of recent vears, chiefly due to American skill. The desk at which you work was made with steel tools. The steel of which these tools were made is a chemical composition. And these wood-cutting tools had first to be made with other tools that could cut steel. Once this process was very slow and expensive. The steel tool used in cutting out other tools became red-hot and lost its "temper," so that it could not cut. Then the worker would lose his temper, too! For he had to stop, resharpen his tools, and waste a great deal of time. Chemists added certain rare metals to the iron that makes ordinary steel, and as a result we have "high-speed steel." High-speed steel is so expensive that tools are tipped with only a fraction of an inch of it, in much the same way that our finest gold pens are tipped with iridium, to keep them from wearing out. This steel tip is many times as efficient as ordinary steel. Without high-speed steel we could not have cheap typewriters, farm implements, and automobiles; for this product has revolutionized the whole metal industry. In your medicine-chest, there probably is a little tube containing a substance which is antiseptic, and which solidifies when exposed to air. If you cut your finger or tear away a hang-nail, you apply a little of this substance, and it forms a skinlike covering. That substance is collodion. Now somewhere near your tube of collodion you may have something made of celluloid, perhaps an eyeshade or a papercutter. In warm weather especially, you must have noticed that anything made of celluloid smells a good deal like something else you keep handy - camphor. That will not seem strange when I tell you how we came to have celluloid. In 1863 a boy named John Wesley Hyatt was working as a printer in Albany, New York. He saw an advertisement offering ten thousand dollars for a substitute for ivory billiard balls, and he began to experiment with the hope of getting this reward. One day, when his fingers were raw from handling type, he went to a cupboard for some collodion to heal his hurts. The bottle containing the collodion had tipped over, and the contents had run out and solidified. When young Hyatt pulled away a little of the stuff from the shelf, he was struck by the fact that it was tough and elastic, and that gave him an idea. He began experiments, trying to make billiard balls out of collodion. Presently he heard that some Englishmen had been trying to make camphor and collodion unite to form a solid. The Englishmen had not succeeded, because they had attempted to get the two substances to unite by adding various other substances to them. But Hyatt simply put a mixture of collodion and camphor into a hot press, and out came a semi-transparent solid, |