I01IE, 
 
 H^585W!WKSW(8Se^ ^; nirii ,' 
 
GIFT OF 
 

 

 The home offers us a variety of activities which help in the best development of body 
 
 and mind. 
 
CIVIC SCIENCE 
 
 IN THE HOME 
 
 BY 
 GEORGE W. HUNTER, PH.D. 
 
 PROFESSOR OF BIOLOGY, KNOX COLLEGE, GALESBURG, ILLINOIS 
 
 FORMERLY HEAD OF DEPARTMENT OF BIOLOGY, DEWITT 
 
 CLINTON HIGH SCHOOL, NEW YORK 
 
 AND 
 
 WALTER G. WHITMAN, A.M. 
 
 EDITOR, GENERAL SCIENCE QUARTERLY 
 
 PHYSICAL SCIENCE DEPARTMENT, STATE NORMAL SCHOOL 
 SALEM, MASSACHUSETTS 
 
 AMERICAN BOOK .COMPANY 
 
 NEW YORK CINCINNATI CHICAGO 
 
 BOSTON ATLANTA 
 

 COPYRIGHT, 1921, BY 
 
 AMERICAN BOOK COMPANY 
 
 A II rights reserved 
 
 H.-W. CIV. SCI. IN HOME 
 
 2 ! ! w. P. i 
 
FOREWORD TO THE TEACHER 
 
 Man's place in relation to science. Living things, man in- 
 cluded, live in an environment which is made up of certain 
 definite factors, and with these factors living things react and 
 interact. Some of these factors are materials things ; other 
 factors are forces. The ultimate result of the complex we call 
 life is the interaction of the materials and forces with the living 
 things on the earth. Man, however, is supreme among animals 
 because of all the animals he alone can control the factors of 
 his environment. He has control of fire and water and elec- 
 tricity. His home has evolved from the cave of primitive man 
 to the complex housing systems of the present age. His com- 
 munal life has brought with it new problems the disposal of 
 wastes, the safeguarding of water and milk supplies, the need 
 of community sanitation and hygiene. His higher civilization 
 demands use of machines, the need of which his forefathers 
 neither knew nor felt ; of transportation and communication ; 
 of more varied and practical education as well. 
 
 Children's interests in science. In the midst of such a life 
 as this our children are growing up. Science beckons to them 
 from every side. In every device used at home for comfort 
 and better living, science speaks. The telephone and telegraph, 
 the trolley and the automobile, the airplane and submarine, have 
 all become part and parcel of their daily lives. Many of the 
 common things of science which directly affect the lives of chil- 
 dren are equally interesting to both sexes. But in any scheme 
 of modern education we must take individual differences into 
 consideration. We no longer educate in the mass. Sex, age, 
 environment, capability, heredity, all are important factors 
 which must be recognized by the modern teacher as having a 
 place in educational practice as well as theory. 
 
 459852 
 
6 FOREWORD TO THE TEACHER 
 
 The project method. Since we must allow for individual 
 differences in our scheme of education, it goes without saying 
 that mass education, which does not account the child as a 
 personality, can no longer be admitted as a part of our scheme. 
 We must take cognizance of all the factors mentioned in the 
 last paragraph ; environment, age, and sex act more uniformly 
 and thus may be taken into account in the forming of classes 
 or groups. But individual capability and endowments, hered- 
 ity's part in the game of lif e ; are much more difficult factors with 
 which to deal. Recent developments in educational psychology 
 show that one method of attack, however, has certain elements 
 which may be used successfully with any group of children not 
 too young to think to a conclusion. Problem solving of one 
 sort or another is common to all the activities of life. It is the 
 one great factor which goes toward making for success or failure 
 in life. It should be part of the mental attitude of every edu- 
 cated person. Problem or project, call it what you will, repre- 
 sents the method by which things worth while in life are 
 achieved. It offers the pupil a method for accomplishing those 
 things in life which mark off greatness from mediocrity the 
 leader from the led. 
 
 Methods in science adapted for children. We hear a good 
 deal nowadays about the logical versus the psychological 
 approach. No teacher, and the word is used in its truest sense, 
 can teach except from the viewpoint of the child. Approached 
 from this angle, the psychological becomes logical. We must 
 have a plan, but we must remember that a plan may sometimes 
 be changed to advantage. Above all we must be human. If 
 we but remember how we looked at things with the eyes of 
 thirteen instead of those of forty-three we will have no difficulty 
 in solving the method of lesson attack. We must remember, 
 too, that concepts grow and are not always brought to ma- 
 turity in one lesson. The cyclic treatment of topics, which has 
 been followed in Civic Science, is a far more natural method of 
 
FOREWORD TO THE TEACHER 7 
 
 acquiring information than a dogmatic statement, made per- 
 haps with proof but dimly comprehended and soon forgotten. 
 
 The textbook in introductory science. Any book in intro- 
 ductory science should be based on the facts we have just men- 
 tioned. It must contain an adequate amount of the basic 
 material from which the interpretation of the common things 
 of interest in life may be gained, and it must also be adapted 
 to start the individual boy or girl whose interest has been awak- 
 ened along the line of the project in which this developing in- 
 terest would naturally flow. Most of all a textbook should 
 interpret to the child the part played by the various natural 
 factors in his environment. It should conceive the child as 
 the center, and all the world of the child revolving around this 
 center. In this conception boys and girls would first become 
 aware of the vital part played by air, water, light, heat, and 
 food on them as individuals within their homes. This much is 
 common to all the application of certain of the general facts 
 learned could then be carried out as special projects by various 
 pupils interested. After the child has learned the meaning of 
 these central factors in the home, the next step would logically be 
 the application of the forces of nature by man in communal life. 
 In short, Civic Science plans to lead the child in a manner which 
 is both logical and psychological from the simple factors which 
 make up his environment as a living thing to the complex com- 
 binations and interactions which have arisen through what we 
 call civilization. It is the interpretation of this complex that 
 Civic Science undertakes with the belief that children, if given a 
 rational point of view, will have enough varied interests to build 
 on the outline which follows. They will thus work toward the 
 solution of those things in science which seem most worth while 
 to them as individuals and most worthy of them as future 
 citizens. 
 
 Acknowledgments. For an incentive to undertake this 
 work, the authors are indebted to those educators who have 
 
8 FOREWORD TO THE TEACHER 
 
 written much on the subject of science for young people, par- 
 ticularly, Thomas M. Balliet, Thomas H. Briggs, John Dewey, 
 Charles W. Eliot, David Snedden, George R. Twiss, and John 
 F. Woodhull. To the many science teachers who have been 
 active in developing general science from its early beginnings 
 to its present state, the authors make full acknowledgment for 
 much help and inspiration. Acknowledgment for illustrative 
 material is made in the text. The drawings were nearly all 
 made by Mr. F. M. Wheat, of the George Washington High 
 School, New York. The following teachers have carefully read 
 the entire proof and made many valuable suggestions : Mr. 
 M. C. Leonard, Vice-principal, Dickinson High School, Jersey 
 City ; Miss A. P. Hazen, Head of the Department of Biology, 
 Eastern District High School, Brooklyn ; and Mr. George C. 
 Wood, Head of the Department of Biology, Commercial High 
 School, Brooklyn ; and also Miss Lydia Holtman, Knox Col- 
 lege, Galesburg, 111. 
 
 REFERENCE BOOKS 
 
 Dewey, Hmv We Think, especially Chapters IV, V, VI, and XV. D. C. 
 Heath Company. 
 
 Flexner, A Modern School, New York Occasional Papers No. 3. General 
 Educational Board, New York. 
 
 Hunter, Laboratory Problems in Civic Biology, Foreword. American Book 
 Company. 
 
 Huxley, Physiography. Appleton Company. 
 
 Snedden, Problems of Secondary Education, Chapter XXI, Houghton Mifflin 
 Company. 
 
 Trafton, The Teaching of Science in the Elementary School, especially Chap- 
 ter V. Houghton Mifflin Company. 
 
 Twiss, Science Teaching, especially Chapters II, HI, TV, and XIX. The 
 Macmillan Company. 
 
 Woodhull, The Teaching of Science, The Macmillan Company. 
 
CONTENTS 
 
 PAGE 
 
 FOREWORD TO THE TEACHER . . . . . . . 5 
 
 PART I. THE HOME AND ITS ENVIRONMENT 
 
 CHAPTER 
 
 I. WHY WE STUDY SCIENCE . . . . . . .11 
 
 II. ESSENTIALS or AN IDEAL HOME 24 
 
 III. NATURAL RESOURCES OF HOME ENVIRONMENT ... 39 
 
 PART II. GOOD HEALTH IN THE HOME 
 
 IV. PURE AIR - .56 
 
 V. WATER IN THE HOME . . . . . . . 7-1 
 
 VI. THE USES OF FOODS . . . . . . ^._ .. 1 . 90 
 
 VII. PURE FOOD IN THE HOME . !".-,. . . ... 115 
 
 VIII. HOUSEHOLD PESTS AND How TO FIGHT THEM . . . 131 
 
 IX. How WASTES ARE REMOVED FROM THE HOME . . . 144 
 
 X. GERM DANGERS AND HEALTH HABITS . . . . 158 
 
 PART III. FEAT IN THE HOME 
 
 XI. FUELS AND THF.IC USES . . . . ... 175 
 
 XII. HEATING Our HOMES. . . v . . ' . . . 188 
 
 XIII. FIRE PREVENTION IN THE HOME 205 
 
 XIV. USES OF CLOTHING ." .'."'. . . .219 
 
 PART IV. LIGHT IN THE HOME 
 
 XV. SOURCES OF LIGHT FOR HOME USE . * . < . . 238 
 
 XVI. IMPORTANCE OF OUR EYES. . . . . . . 253 
 
 PART V. THE HOME AND ITS SURROUNDINGS 
 
 XVII. MAKING AND BEAUTIFYING THE HOME ... . 267 
 
 XVIII. PLANNING THE HOME GROUNDS . . . ., . . 286 
 
 9 
 
io / CONTENTS 
 
 CHAPTER PAGE 
 
 XIX. THE HOME GARDEN 297 
 
 XX. PLANT FRIENDS AND PLANT PESTS 314 
 
 PART VI. DEVICES FOR LABOR SAVING AND 
 CONVENIENCE 
 
 XXI. SOME SIMPLE MACHINES IN THE HOME . . . .331 
 XXII. How ELECTRICITY Is USED IN THE HOME . . . 344 
 
 XXIII. How ELECTRICITY Is CONTROLLED IN THE HOME . . 359 
 
 PART VII. RECREATION IN THE HOME 
 
 XXIV. INDOOR RECREATION 371 
 
 XXV. OUTDOOR RECREATION .390 
 
 INDEX . . . . - 409 
 
PART I. THE HOME AND ITS 
 ENVIRONMENT 
 
 CHAPTER I 
 WHY WE STUDY SCIENCE 
 
 Problems. i. Why is some knowledge of science essen- 
 tial to us? 
 
 2. Why is the " method of science " important? 
 
 3. What is a science project? 
 
 Living in an age of science. Do you ever stop to think 
 you are living at a time when science has done more to make 
 everyday life comfortable than at any other time in the 
 world's history? You sleep at night in a bed, the springs 
 and parts of which were made by machinery, and the covers 
 of which were woven by a complicated process ; you wash 
 with soap made by chemical processes ; you eat prepared 
 breakfast foods, and cook on a gas, coal, or wood stove. 
 You eat in machine-pressed dishes ; ride to school on 
 electric cars, or trains, or automobiles, the parts of which 
 were made by machines. Every part of your waking and 
 sleeping hours you come in contact in some way with de- 
 vices which involve a knowledge of science, and yet how 
 few actually know very much about the science which 
 underlies all these useful and beneficial inventions. 
 
12 
 
 '. /tyJtY:WE STUDY SCIENCE 
 
 /M^';g: ^ogress: in "science recent. Have you ever 
 triougM how ma'riy'tKrrigs have come into common use since 
 
 your father and mother 
 were born? X-rays, 
 flash lamps, radium, 
 the pianola, liquid air, 
 submarines, gas en- 
 gines, sky scrapers, 
 harvesters, vacuum 
 brakes, fireless cookers, 
 vacuum bottles, vacu- 
 um cleaners, street 
 cars, airplanes, hydro- 
 planes, motor cycles, 
 gas mantles, automo- 
 biles, carpet sweepers, 
 asphalt paving, safety 
 matches, pneumatic ap- 
 pliances, moving pic- 
 tures, typewriters and 
 adding machines, wire- 
 less telegraphy, pneu- 
 matic mailing tubes, 
 electric heating and 
 cooking apparatus, tur- 
 bines, paper towels, 
 electric lighting, reen- 
 forced concrete, sani- 
 tary drinking fountains 
 and cups, and a great 
 
 A triumph of modern science. How many scien- many Other things 
 tific inventions can you think of which are prob- , . . 
 ably utilized in this large office building ? WnlCn WC JiaVC COlTl&-tO 
 
SCIENCE USED IN THE DISCOVERY OF MALARIA 13 
 
 look upon as necessities of life. Could any one be con- 
 sidered educated without knowing more than we do about 
 science ? 
 
 Reasons why we should study science. Since scien- 
 tific devices are used so much in and about our homes, we 
 ought to have at least some practical knowledge of the 
 common things in science, so that we may know how to 
 help solve the problems that come to us. With a little 
 knowledge, we can fix leaking faucets; we can find out 
 why the electric bell does not ring ; we can explain why 
 the ice box is not preserving food properly or why the 
 bread does not rise. Some day we shall be called upon to 
 earn our own living. Opportunities for promotion in 
 many fields of work will be small for those who do not 
 understand common things in science. The practical ma- 
 chinist who can apply his knowledge of the principles of 
 science to the working of his machine is the foreman in 
 the shop. Then too, our health depends in a measure upon 
 the knowledge of science. It used to be thought that 
 diseases like diphtheria, for example, were the dispensation 
 of Providence, but nowadays we look nearer for the cause, 
 and find it to be germs. 
 
 An example of how the method of science was used in 
 the discovery of malaria. The Italians thought formerly 
 that malaria was caused by bad air, and hence they called 
 it mat aria. The discovery of malaria is an interesting 
 story. It was near the end of the last century that a 
 French physician named Laveran discovered that malaria 
 was probably caused by a tiny parasite which lived in 
 the blood cells of man. He reasoned that this was so 
 because he found the little animal only in the blood cells 
 of those suffering from malaria. A little later an English 
 
14 WHY WE STUDY SCIENCE 
 
 army surgeon named Ross, working in India, found after a 
 long series of experiments, that mosquitoes had something 
 to do with malaria. He knew that they were blood-sucking 
 insects, and that they were always present where malaria 
 
 The life history of the malarial parasite. This cut shows parts of the body of the 
 mosquito and of man. The mosquito injects the crescent-shaped bodies into the 
 blood of man. These enter the blood corpuscles, develop spores which, after being 
 released from the corpuscle, form two kinds of cells. These two forms of the 
 parasite are sucked with the blood into the body of the mosquito, where the other 
 part of the life cycle of the parasite takes place. 
 
 was frequent. He reasoned that mosquitoes might carry 
 this germ. He worked a long period of time before he 
 found finally that a certain kind of mosquito, called 
 anopheles, had some unusually tiny bodies attached to the 
 
SCIENCE USED IN THE DISCOVERY OF MALARIA 15 
 
 inside of their stomachs. These little microscopic bodies 
 were full of black specks. Ross found later that these 
 black specks were only present after a mosquito sucked 
 blood from a person having malaria. By a process of 
 reasoning and experiments, he discovered finally that not 
 only did these mosquitoes carry malaria, but that people 
 could not have malaria unless they were bitten by one of 
 the anopheles mosquitoes, for a malarial parasite has to 
 live a part of its life in the body of the person who has 
 malaria and another 
 part of its life in 
 the body of the mos- 
 quito. 
 
 Then came the 
 testing of this re- 
 markable theory in 
 Italy. A number of 
 people who worked 
 
 in a malarial region, 
 near the city of 
 Salerno, were per- 
 suaded to live in 
 houses which had 
 been carefully 
 screened. It was 
 discovered that the 
 malarial mosquito 
 came out only at 
 night. Practically none of the people who stayed in the 
 house at night behind their screens got malaria, although 
 almost all of the people in the immediate neighborhood 
 were suffering from the disease. 
 
 The final proof that the mosquito carries malaria. 
 
16 WHY WE STUDY SCIENCE 
 
 The final proof came when two English physician 
 Dr. Manson and Dr. Warren, allowed themselves to 1 
 bitten in England by mosquitoes which had been sei 
 from Italy, but which had been previously fed on the bloc 
 of a person having malaria. Neither of these men ha 
 had malaria previously, but eighteen days after they we: 
 bitten, they both came down with the disease. This 
 an excellent example of how scientific method is applu 
 in the discovery of new facts important to mankind. A 
 we have to do to escape malaria is to be sure that malari 
 mosquitoes do not bite us. 
 
 A study of the method of science. If we study th 
 scientific method more fully, we find, first, that the scientii 
 has a reason for trying to solve a problem. He thinks ov< 
 this problem, and finally gets clear in his mind just wtu 
 he wants to find out. He has then fixed his problem 
 His next step is to try to find out some method or methoc 
 of solving it. This he does by thinking over various waj 
 in which he can attack it. He finally fixes on some metho 
 which he tries out by means of experiments to test wheth< 
 his theories are correct. He may and often does ha\ 
 to perform hundreds of experiments before he is satisfie 
 that he has a correct solution. This was the case with D 
 Ross as he worked over his problem of how the malarii 
 mosquito played a part in giving the disease to peopL 
 At length, after he has satisfied himself that he has th 
 solution to his problem, he must then put it to a practice 
 test. This was done, you remember, by the English do< 
 tors who allowed themselves to be bitten by the mosquitoe: 
 and thus proved that mosquitoes transmit malaria. 
 
 The method of science useful in daily life. This metho 
 of science which we have just described should become 
 
SCIENCE USED IN STRAIGHT THINKING 17 
 
 part of the daily life of every educated person. It should 
 become a habit of mind, a way of thinking. Scatter- 
 brained people may think ; we find, in fact, that we think 
 when we daydream, but we do not organize our thoughts, 
 nor do we put them to any use. Science was once called 
 by a great scientist, " organized common sense," and such 
 it really is. Nowadays too many people reason from state- 
 ments heard which they want to be true. They have 
 
 We estimate, we compare, we verify in the method of science and in everyday life. 
 
 heard only one side, and do not care to know any other. 
 Bolsheviki are good examples of such people. People who 
 can think straight are the ones who succeed in life. A 
 dangerous attitude of mind results from careless, wrong 
 modes of thinking. 
 
 How the method of science is used in straight thinking. 
 When we think properly, we are using some steps that 
 the scientist uses when he plans to work out his problem. 
 Take, for example, any question in your daily life that comes 
 to you. It comes in the form of a problem. Your father 
 has rented a new house. Your mother has promised you 
 a room of your own, and a new rug for it.. You are visiting 
 the house. You look at the room, and try to make up your 
 mind as to its size. You think it is about ten feet by twelve 
 
 H.-WHIT. CIV. SCI. IN THE HOME 2 
 
i8 WHY WE STUDY SCIENCE 
 
 feet, and therefore you will want a rug not larger than 
 eight feet by ten feet. You have estimated the size, but 
 you may be wrong. You compare it with some room with 
 which you are familiar in your own house. Yes, it seems 
 to be about ten feet by twelve feet in size, but you decide 
 it will be better to measure it. So you get a tape measure 
 and you find that you were practically correct. You have 
 verified your conclusion. In other words you have followed 
 the method of scientific thought. You have estimated the 
 size, compared it with other rooms, and reached a conclu- 
 sion; you measured it, and found you were correct. 
 
 The habit of scientific thinking. If we use this method 
 at all times we shall acquire a habit of mind that will be very 
 useful in later life. This method teaches us to be accurate 
 in our judgment. It teaches us to observe. It teaches 
 us not to accept a statement without evidence. It teaches 
 us to weigh the evidence, then draw our conclusions and 
 finally to verify our conclusions. This habit of mind is 
 worth much more than any number of facts that this book 
 can give. 
 
 How we use this method in our home work. We get 
 out of life just about what we put into it. Each one of us 
 will get just as much from the method of science in this 
 course as we are willing to work out with enthusiasm. 
 In any event, boys and girls taking a course in general sci- 
 ence will get a great deal of valuable information which 
 will be useful during life. Much of the information will 
 be found in this book and in other books which are suggested 
 in the reference lists. But the method of doing things we 
 must learn outside the reading books. To work out home 
 problems or projects with such simple apparatus as is 
 needed to draw conclusions, is far more profitable than 
 
THE PROJECT 19 
 
 memorizing any number of facts, for by scientific methods 
 such as these, people make discoveries which are of value 
 to the world. 
 
 The project and how it may be worked out. You are 
 the one to plan your own project and work out the prob- 
 lems connected with it. It will not mean so much to you 
 unless you want to know about the thing you are trying to 
 do. Books, people, and experiments may all help toward 
 the achievement of your project, but you must carry it 
 through yourself. Take, for example, a project to deter- 
 mine the best methods of cleaning a room. This would 
 mean investigation on your part of the construction of 
 brooms, wet and dry dust cloths, dustless dusters, carpet 
 sweepers, vacuum cleaners, and of the methods used in per- 
 forming the work. Not only should the mechanical work- 
 ing of these devices be understood, but also the amount of 
 time and labor spent in cleaning a room with each must 
 be estimated or measured separately. We would naturally 
 be interested to know also how much this time is worth, 
 and that should go into our estimate of the value of the 
 different methods. But more important is the knowledge 
 of how much dust is raised by each method and the 
 relative number of bacteria which would be stirred about 
 in the air. To understand this it would be necessary for 
 us not only to know something about the bacteria them- 
 selves, but also to perform experiments with a series of 
 prepared culture dishes by which we would determine the 
 relative number of bacteria in the air during each method 
 of cleaning. These culture dishes may be obtained from 
 the board of health, or a good laboratory, or a culture 
 medium made and the dishes filled and sterilized in the 
 school laboratory. Eventually you have a series of facts 
 
20 WHY WE STUDY SCIENCE 
 
 which enable you to determine which is the best method 
 of cleaning a room. A written report giving all data by 
 which you have reached your conclusions and including 
 interesting facts learned by your study completes your 
 project. 
 
 In order that you may be able to choose some one project 
 in which you will be interested, a suggested list of projects 
 follows at this time. These projects will be mentioned 
 again in connection with the chapters with which they are 
 connected. But since projects require planning and often 
 a considerable length of time to work out, you should choose 
 your projects now and begin to plan work on them at once. 
 In this way you will be ready to report to the class at the 
 right time. 
 
 A LIST OF SUGGESTED PROJECTS 
 
 1. To learn the advantages of renting and of owning one's home. Page 24. 
 
 2. To make a home laboratory. Page 39. 
 
 3. To discover and remedy harmful effects of air about the home. Page 39. 
 
 4. To increase my lung capacity. Page 56. 
 
 5. To secure pure air in my bedroom. Page 57. 
 
 6. To prepare for life saving where artificial respiration must be used. 
 
 Page 57. 
 
 7. To make a lift pump. Page 74. 
 
 8. To see how much water is wasted by dripping faucets. Page 74. 
 
 9. To see what nutrients are in the foods commonly used in my home. 
 
 Page 90. 
 
 10. To obtain starch from potatoes. Page 90. 
 
 11. To plan for economical buying for our family for one week. Page 91. 
 
 12. To test and preserve eggs for home use. Page 115. 
 
 13. To pasteurize the home milk supply. Page 116. 
 
 14. To exterminate flies from my home. Page 131. 
 
 15. To prepare myself to keep the house plumbing in order. Page 144. 
 
 16. To compare my daily use of time with an ideal plan. Page 158. 
 
 17. To form correct health habits. Page 159. 
 
 18. To make a house thermometer. Page 175. 
 
 19. To qualify as an expert heating device operator in my home. Page 188. 
 
TOOLS WITH WHICH WE WILL WORK 21 
 
 20. To learn how my coal range is constructed and how to run it. Page 189. 
 
 21. To remove the fire hazards from my home. Page 205. 
 
 22. To find out what my clothes are made of. Page 219. 
 
 23. To improve the lighting in my home. Page 238. 
 
 24. To remedy any eye defects I may have. Page 253. 
 
 25. To plan an ideal house. Page 267. 
 
 26. To become a landscape gardener for my own home. Page 286. 
 
 27. To learn the soil needs in my garden for any particular crop. Page 297. 
 
 28. To eliminate the plant pests from my home grounds. Page 314. 
 
 29. To keep the machines of the home in good working condition. Page 33 1 . 
 
 30. To install an electric bell in my home. Page 344. 
 
 31. To install a night light in my bedroom. Page 359. 
 
 32. To understand the mechanism of the piano and the piano player. Page 
 
 37i- 
 
 33. To plan how to utilize the playgrounds of the home lot. Page 390. 
 
 Tools with which we will work. A notebook in which to 
 make careful notes of all work done is an essential part of 
 our equipment. We should always take notes of every- 
 thing we do, both in the laboratory and at home. These 
 notes should be carefully kept, and drawings made to illus- 
 trate them, either with a hard pencil or with a drawing pen. 
 We must learn to use instruments with which to measure. 
 The use of the metric system is best for all scientific meas- 
 urements, and a knowledge of the metric tables will be 
 found valuable. We must also know how to use a com- 
 pass and a T-square, and other instruments useful in diagram 
 making. Perhaps the most essential thing of all is to learn 
 the value of accurate figures, as this is needful in the mak- 
 ing and understanding of graphs. A graph is the diagram- 
 matic representation of a certain number of figures. An 
 example is seen in the diagram on page 22, in which we are 
 illustrating the changes of temperature which take place 
 during a day. The figures of the thermometers and clock 
 faces show the temperatures at different times durin^-the 
 day and the hours. The figure on the squared paper shows 
 
22 WHY WE STUDY SCIENCE 
 
 how the graph is constructed. It is important to learn 
 the making and understanding of simple graphs, as a 
 knowledge of this kind should be part of the equipment 
 
 
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 readings show. 
 
 of every well-informed boy and girl to-day. Last of 
 all, and perhaps most important, we need enthusiasm for 
 our 'work. Success along any line requires attention, 
 thought, and interest. Interest is valuable in school work 
 
REFERENCE BOOKS 23 
 
 and failure is often due to indifference. Surely in this 
 great world of science about us, there is enough to interest 
 each one of us. 
 
 REFERENCE BOOKS 
 
 Fall, Science for Beginners, Chapters I and II. World Book Company. 
 
 Hunter, A Civic Biology, Chapter I. American Book Company. 
 
 Hunter, Laboratory Problems in Civic Biology, Chapter I. American Book Company. 
 
 Lee, Health and Disease (Advanced), Chapter XV. Little, Brown, and Company. 
 
 Ritchie, A Primer of Sanitation, Chapter XXIV. World Book Company. 
 
 Smith and Jewett, Introduction to the Study of Science, Chapter XII. The Mac- 
 
 millan Company. 
 Winslow, Healthy Living, Chapter XXIII. Merrill Company. 
 
CHAPTER II 
 
 THE ESSENTIALS OF AN IDEAL HOME 
 
 Problems. i. To see how marts idea of home has 
 changed since remote ages. 
 
 2. To see what our present homes do for us. 
 
 3. To learn how to secure efficiency in the home. 
 
 4. To see what a home can contribute to our health. 
 
 Home Laboratory Exercise. To make out a score card for my own 
 home. 
 
 Project I. RELATIVE ADVANTAGE OF RENTING AND OF BUILD- 
 ING ONE'S HOUSE. 
 
 If your parents are renting a house or apartment, you may be 
 interested to undertake this project. 
 
 1. Selection of a desirable home site. Look- over the vacant 
 lots available for building in various sections of the town or city. 
 Value of lot ? Why selected ? 
 
 2. From study of magazines (consult library) select suitable 
 house plans. Probable cost ? Other expenses to equip the house ? 
 
 3. How could this house be built ? Mortgage. Building loans. 
 Cost of hired money. How much must the owner invest ? 
 
 4. Compare yearly cost of living in one's own house and in rentals. 
 
 What is a home ? To the boy or girl who reads this, 
 home is the place where he or she slept last night, arose 
 this morning to an early breakfast, and then left bright 
 and early so as to be in time for school. A boy probably 
 thinks of the closet in his bedroom, filled with his books 
 
 24 
 
HOW HOMES HAVE CHANGED 25 
 
 and games, his skates and gun. The girl thinks of her 
 dainty bedroom, with its pretty pictures and hangings, 
 and both probably think more than anything else of 
 the father and mother who make life really worth while 
 at home. Home, then, is more than a place to live in ; it 
 means father, mother, brothers, and sisters ; it means 
 
 A suburban home. 
 
 family life, with all its give and take, its unselfishness and 
 loyalty to the ideals which father and mother believe to be 
 right. 
 
 How homes have changed from their first beginnings on 
 the earth. There was a time a good many thousand 
 years ago when people living on the earth had no real 
 homes. They were nomads, traveling from one place to 
 another, staying here a night and there a day, never remain- 
 ing long in one place. Then came the discovery of fire. 
 
26 
 
 THE ESSENTIALS OF AN IDEAL HOME 
 
 With the fire they warmed the caves ; and in consequence 
 people lived in greater comfort and made these caves the 
 first real homes. Then they began to domesticate or tame 
 the wild horses and wilder cattle with which they came in 
 contact and to discover that certain fields of wild grasses 
 
 were good fodder 
 for their horses and 
 cattle. Later these 
 wild grasses were 
 cultivated and the 
 first cereal crops 
 came into existence 
 for man. Man be- 
 gan to build perma- 
 nent homes now, be- 
 cause he had food 
 to eat and fire with 
 which to cook. 
 Probably the first of 
 these homes were 
 nothing but tents 
 made of skins, or 
 rude huts, but they 
 were enough for the 
 few needs of primitive men and women. Food and cattle 
 were more abundant in certain places, where water and 
 wood for fire were plentiful. These advantages attracted 
 a number of people who came to live near each other. 
 Mutual protection was gained also, and so we have the 
 beginnings of a town or community. It is a long and far 
 cry from the tiny collection of huts to the modern great 
 city, but our cities and towns of to-day have grown from 
 
 Indian tepee. A type of very primitive home. 
 
THE IDEAL HOME SITE 
 
 27 
 
 just such beginnings as we have been talking about in 
 this paragraph. 
 
 What home life does for us. Doubtless each one of us 
 thinks of his home as a place for shelter, for food, for 
 material comforts of all kinds, but it should be more than 
 this. The home should be the center of a little group in 
 which absolute loyalty is seen instead of selfishness and in- 
 dividual rights. At the present time this country of ours 
 suffers much because of the lack of team work on the part 
 of all men and women who share its benefits. Real home 
 life should teach us cooperation and unselfishness, not 
 individualism and selfishness. 
 
 The home requirements of civilized man. Man, if 
 he is to be a healthy individual, and if he wishes to remain 
 so, should have the following : 
 
 1. Pure air this means air free from dust and germs, 
 smoke and bad odors. 
 
 2. Pure water water free from all dirt and germs. 
 
 3. Good and plentiful food, well taken care of and prop- 
 erly cooked. 
 
 4. Moderate heat, both in summer and in winter. 
 
 5. Plentiful light, both natural and artificial. 
 
 6. Clothing suitable to the time of year. 
 
 7. A home well planned, well ventilated, well lighted, 
 with some ground around it for a garden and playground. 
 If the latter is not possible, playgrounds and parks should 
 be provided in the near vicinity. 
 
 The ideal home site. We have already spoken of the 
 detached house being the ideal place in which to live. This 
 is not only because of the air space around it on all sides, 
 making it cooler in summer and giving good ventilation, 
 but also because of the privacy which comes from living 
 
28 
 
 TIIK I'SSKNTIALS OF AN IDKAL TTOME 
 
 in ;i house separated from its neighbors, I )rt;i< lied house's 
 ;irc more frequently owned by those who live in them, ;ind 
 this helps to make the owner more thrifty. One is always 
 more , -i rel'iil of a house he owns than of one he rents. 
 Thru, too, the garden is indire<lly a sourer of profit as 
 well as of health and pleasure. Many families furnish all 
 
 The house in the diagram IB ideally located as regards drainage. The irregular lines 
 are contour lines, each representing 5 feet in altitude. Make a diagram in your 
 notebook showing a cross section through house and grounds, indicating differ- 
 ences in elevation. 
 
 the vegetables nrrdrd during the summer from a small 
 garden, carefully planned and tended. 
 
 If we live in the city, both light and air are very im- 
 portant factors for our consideration. In most cities 
 nowadays, good laws have been made which require wide 
 air shafts and sufficient window space in all apartments 
 or dwellings. But in many cities in the United States, 
 we still see houses like the one shown in the picture, m a 
 
THE IDEAL HOME SITE 
 
 29 
 
 A congested district. 
 
 Compare this detached house with the houses shown in the picture above. In which 
 place would you rather live ? 
 
THE ESSENTIALS OF AN IDEAL HOME 
 
 congested district, where neither light nor air is abundant 
 
 enough for healthy living. 
 
 Some ways to work for an ideal home. No doubt 
 
 we would all like to live in a home that is ideal. While 
 
 this is not possible, 
 for no one of us is 
 perfect, yet we can 
 do a great deal to 
 better the condi- 
 tions under which 
 we live. The fol- 
 lowing paragraphs 
 will tell us some of 
 the ways in which 
 we may improve 
 our homes. 
 
 Crowding a men- 
 ace to health. - 
 Although it is not 
 always easy for us 
 to change the place 
 where we live, yet 
 when we realize 
 that crowding in a 
 big city frequently 
 
 This map shows how cases of tuberculosis recur in the matp; a hip"hpr 
 same houses year after year. Each black dot repre- UlgUC 
 
 sents one case of tuberculosis. The region is one of rl^a+Vi ratA -or A 
 
 the most densely populated regions in New York. UCdLll idLC, 
 
 should be willing to 
 
 plan for a better place in which to live. The map shown 
 in the illustration gives ample proof that some crowded 
 conditions help to cause diseases. All of the little dots in 
 the picture represent cases of tuberculosis. Notice how 
 
 
 
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CARELESSNESS 31 
 
 numerous the cases are in certain houses. This may mean 
 that under the crowded conditions in which people lived, 
 the disease was more easily transmitted from one person 
 to another. A small one-family house, if one can afford 
 it, is far better than the crowded apartment or tenement. 
 
 Cleanliness a factor in the home. A large, airy house 
 in a good location is not the only necessity for good health. 
 If houses are kept closed long, or allowed to run down ; if 
 they have leaky gas or sewage pipes, or if they are over- 
 run with rats or infested with flies, they are far from being 
 sanitary and healthful. A clean fly may have twenty thou- 
 sand germs tucked away on its legs or body, while a dirty 
 one may carry several million. We can at least keep our 
 homes clean and free from dirt, and we can also be clean 
 in our own person and clothes. 
 
 Carelessness. Carelessness always plays a big part 
 in making our homes unpleasant places in which to live. 
 There are numerous calamities besides sickness which may 
 come to the home. One of the most treacherous is fire. The 
 fires in the United States average 1500 a day. The cause 
 of a great many of these is a carelessly dropped match, 
 a lighted cigarette, the gas turned on and forgotten, or the 
 electric iron thoughtlessly left, in other words, carelessness. 
 
 What is more valuable than a pair of good eyes? Close 
 your eyes for five minutes, and think what life would 
 be if, instead of five minutes, it was for five years, or for 
 your whole life that you were to be surrounded by dark- 
 ness. Think of what you would miss in life. Carelessness 
 in caring for eye defects, such as nearsightedness or far- 
 sightedness, or careless use of lights and lighting, all of 
 these things may mean a lessened use later in life, or per- 
 haps loss of use of these important organs. 
 
32 THE ESSENTIALS OF AN IDEAL HOME 
 
 Efficiency in the home. Nowadays we frequently hear 
 the word " efficiency." We have efficiency engineers in 
 
 Thomas Edison, one of our greatest inventors. 
 
 great manufacturing plants to see that the most is made of 
 the machinery, and the time of the workmen. Why should 
 not each one of us be an efficiency engineer in our own 
 home? We should all train ourselves to discover where 
 there is wasted energy, and then study how to prevent it. 
 In factories machines have largely replaced hand labor. 
 The machines last only a few years, and are then replaced 
 by others which can do the work better. Why not apply 
 this business principle of efficiency to our homes ? It would 
 mean more time for recreation, reading, and social life. 
 The reduction of house work and the use of sanitary con- 
 veniences would often do much to make the health of the 
 
RECREATION IN THE HOME 
 
 33 
 
 family better. How is it in your home? Could a few 
 dollars be well spent for equipment which would make 
 mother's life easier? Why not study the situation as 
 a home project? 
 
 The habit of work. The great inventor, Edison, in 
 his seventies, is able now to work long hours day after day. 
 It was his habit to work, even when he was a small boy. 
 We find that most men and women who have developed 
 into leaders accustomed themselves to work when they 
 were young. Learn to accept your share of the home 
 
 123 4 
 
 Practice these exercises every morning and evening and watch the effect upon your 
 general development. (After Tolman.) 
 
 duties, for thus you will develop a sense of responsibility 
 and habits of industry. Learn to do home tasks willingly, 
 for thus you will develop unselfishness. The efficiency of 
 a household is lowered by every idle member who lives 
 there. Learn now to be a helper, and some day you will 
 assume more easily the responsibilities which will come to 
 you when you are grown up. 
 
 Recreation in the home. It is an old saying that all 
 work and no play makes Jack a dull boy. All work is 
 wrong, and all play is wrong, but play is just as important 
 as work for normal boys and girls. Recreation sometimes 
 means re-creation, for we are really made over by doing 
 
 H.-WHIT. CIV. SCI. IN THE HOME 3 
 
34 
 
 THE ESSENTIALS OF AN IDEAL HOME 
 
 interesting things which rest our body and mind. Reading, 
 music, visiting our friends, playing games, are all good 
 types of indoor recreation and outdoor exercise and are 
 absolutely necessary for a growing boy and girl. Our lungs 
 need developing, as do our muscles. Baseball, tennis, walk- 
 ing, hiking, canoeing, camp- 
 ing all of these have their 
 place, and even if we have 
 no opportunity for these, a 
 little yard space is sufficient 
 for such games as tether- 
 ball, Russian nine-pins, vol- 
 ley ball, or hand ball. 
 
 You must obey health 
 rules. Most of all, daily 
 following the rules of good 
 health will do more than 
 anything else to make your 
 life a happy and a helpful 
 one. Did you ever think 
 what it would mean not to 
 be able to run a foot race, or 
 make a high jump, or play a 
 game of tennis or baseball ? Without proper attention to 
 the rules of right living, proper eating, drinking, breathing, 
 and care of your bodily organs, even the strongest of you 
 may become weak. You may be in the best of health now, 
 but if you are not willing to continue the proper care of 
 your body, you may pay the cost later. Do not try to cheat 
 somebody else by not brushing your teeth to-day, or not 
 wearing the warm clothes that mother suggested, or by 
 reading too long in that poor light, for the only one you 
 
 This boy, as a result of exercise, fresh 
 air, and nourishing food, has a strong 
 healthy body. He is able to take care 
 of himself. (After Davison.) 
 
SCORING THE HOME 35 
 
 are cheating is yourself. Be faithful in your health habits ; 
 it pays in the long run. 
 
 Scoring the home. Emerson has said that we must 
 "hitch our wagon to a star." This really means that we 
 must have high ideals in life. In order to estimate your own 
 homes in the light of the chapter you are now reading, there 
 follows a score card which each boy and girl should study, 
 and then for his or her own satisfaction attempt to 
 score his or her own home. Remember to be honest in 
 your scoring, and although your score may seem low, 
 nobody's score will be perfect, because we have " hitched 
 our wagon to a star." This home project will be a pre- 
 liminary survey of our homes, and in a later chapter, we 
 shall make a more careful study under each of the head- 
 ings in this score card. You will notice that this first 
 score card has three columns headed respectively, " Per- 
 fect score," " My first (guess) score " and " My final (real) 
 score." This means that you are to make an outline of 
 this score card as a preliminary exercise for your note- 
 book. In the second column place the score you think 
 you ought to have, after having first consulted the score 
 cards you are referred to at the ends of certain of the chap- 
 ters. The scores should be totaled and a grand total ob- 
 tained. The third column marked " My final (real) score " 
 will be filled little by little as you study the future chapters. 
 You will probably find that your first estimate was far too 
 high and thus the third column will serve to check up 
 on your " guess " or first estimate. This shows a use of 
 the scientific method referred to in the first chapter, and 
 will be excellent practice for you. 
 
 The score card that is given is only a suggestion and 
 may be advantageously changed to meet local conditions. 
 
THE ESSENTIALS OF AN IDEAL HOME 
 
 HOME SCORE CARD 
 
 PERFECT 
 
 SCORE 
 
 MY FIRST 
 
 (GUESS) 
 
 SCORE 
 
 MY FINAL 
 
 (REAL) 
 SCORE 
 
 ENVIRONMENT 
 
 Pure air 
 
 Pure water 
 
 Well-drained soil 
 
 Plenty of sunlight 
 
 Not too great extremes of heat or cold 
 Foods supplied from home garden . . 
 Foods cheap and good 
 
 WATER IN MY HOME 
 
 Safe supply 
 
 Ample supply .... 
 All parts or home supplied 
 Good condition plumbing 
 Soft water provided . . . 
 
 3. FOODS m MY HOME 
 
 A well-balanced diet 
 
 Right diet for occupation and environment 
 
 Foods easily digestible 
 
 Foods economical 
 
 Foods properly prepared and cooked . . 
 
 4. CARE OF FOODS IN MY HOME 
 
 Clean kitchen and utensils 10 
 
 Good refrigeration 10 
 
 Sterilization and pasteurization 10 
 
 Proper use of preservatives 10 
 
 Protection from insects, etc 10 
 
 5. HOUSEHOLD PESTS 
 
 No flies 10 
 
 No mosquitoes . 10 
 
 No body pests (fleas, bedbugs, head lice) . 10 
 No food or cloth pests (roaches, ants, wee- 
 vils, clothes moths, etc.) 10 
 
 No rats or mice 10 
 
 6. REMOVAL OF WASTES 
 
 Exposed plumbing 10 
 
 All porcelain fixtures 10 
 
 Have a working knowledge of system . . : 10 
 
 Sewer connections or septic tank .... 10 
 
 Garbage pail pr<||>erly kept 10 
 
 7. PERSONAL HEALTH HABITS 
 
 (See page 173) 100 
 
 PROTECTION AGAINST DISEASE 
 
 (See page 174) 50 
 
 8. FUELS 
 
 Warmth obtained 10 
 
 Ventilation and protection against loss of 
 
 heat 10 
 
 Economy of fuel 10 
 
 Economy in time and work in attending to 
 
 heating plant 10 
 
 Efficiency of cooking stove ...... 10 
 
 9. CLOTHING, BATHING, AND VENTILATION 
 
 Proper outer clothing 10 
 
 Proper and clean underclothing .... 10 
 
 Bathing 10 
 
SCORING THE HOME 
 
 HOME SCORE CARD Continued 
 
 37 
 
 
 PERFECT 
 SCORE 
 
 MY FIRST 
 (GUESS) 
 SCORE 
 
 MY FINAL 
 (REAL) 
 SCORE 
 
 g. CLOTHING, ETC. Continued 
 Proper bedroom hygiene . 
 Proper home ventilation 
 
 10 
 10 
 
 
 
 10. LIGHTING MY HOME 
 Sunlight plentiful 
 
 10 
 
 
 
 \Yindows ample, wall papers good reflectors 
 Artificial lighting economical 
 Proper lighting for all kinds of work . . . 
 Good systems of lighting used 
 
 10 
 10 
 10 
 10 
 
 
 
 ii. PROPER CARE OF MY EYES 
 See Chapter XVI, Page 266, for items . . 
 
 So 
 
 
 
 12. MY HOUSE 
 Detached house 
 
 IO 
 
 
 
 
 IO 
 
 
 
 Bedrooms and comfortable living room . . 
 
 10 
 IO 
 
 
 
 Convenient kitchen 
 
 IO 
 
 
 
 Bathroom, hot and cold water 
 Heating plant adequate 
 
 10 
 IO 
 
 
 
 
 
 
 
 House new 
 
 IO 
 
 
 
 House in good repair 
 
 10 
 
 
 
 13. THE HOME GROUNDS OR PARKS, PLAY- 
 GROUNDS, AND LIBRARY 
 (See pages 295 and 296) . . . . . . .. 
 
 53 
 
 
 
 14. MY HOME GARDEN 
 General appearance ; . 
 Choice of vegetables 
 
 IO 
 10 
 
 
 
 
 IO 
 
 
 
 Evidence of planning . . 
 
 5 
 
 
 
 Care of tools 
 
 5 
 
 
 
 Valve of produce ... 
 
 IO 
 
 
 
 
 
 
 
 15. DEVICES FOR CONVENIENCE AND LABOR SAV- 
 ING IN MY HOME 
 Electric and gas devices 
 Cleaning helps 
 Kitchen helps 
 Other helps : sewing machine, telephone, etc. 
 Tools and work room 
 
 15 
 
 10 
 10 
 10 
 
 5 
 
 
 
 1 6. MY INDOOR RECREATIONS 
 Score based on points mentioned in Chapter 
 XXIV. See Score Card, page 388 . . . 
 
 SO 
 
 
 
 17. MY OUTDOOR RECREATIONS 
 Score based on points mentioned in Chap- 
 ter XXV. See Score Card, page 407 . . 
 
 50 
 
 
 
 GRAND TOTAL 
 
 1000 
 
 
 
38 THE ESSENTIALS OF AN IDEAL HOME 
 
 Why not undertake as a special project the improvement of 
 the series of score cards, with addition to or subtraction 
 from this list. 
 
 REFERENCE BOOKS 
 
 Allen, Civics and Health (Advanced). Ginn and Company. 
 
 Conn, Bacteria, Yeasts, and Molds of the Home. Ginn and Company. 
 
 Davison, Human Body and Health. American Book Company. 
 
 Hunter, A Civic Biology, Chapter II. American Book Company. 
 
 Hunter, Laboratory Problems in Civic Biology, Chapter II. American Book Com- 
 pany. 
 
 Jewett, Town and City. Ginn and Company. 
 
 Tolman, Hygiene for the Worker. American Book Company. 
 
 Van Rensselaer Rose Canon, Manual of Home Making (Teacher's use), Chap- 
 ters I, II. The Macmillan Company. 
 
CHAPTER III 
 NATURAL RESOURCES OF HOME ENVIRONMENT 
 
 Problems. i . What things about us do we get directly 
 from nature? 
 
 2. What is air, and how does it satisfy a human need? 
 
 3. How are we dependent upon the sun? 
 
 4. Why are water and food of such importance? 
 
 Experiments. i. To show the reality of the air. 
 
 2. To prepare and observe the properties of the principal gases in the 
 air. 
 
 3. To show what part of the air is oxygen. 
 
 Project I. To MAKE A HOME LABORATORY. 
 
 1. A suitable space and table. 
 
 2. What source of heat? 
 
 3. How arrange to collect gases? 
 
 4. What equipment needed to start ? 
 
 5. Cost? 
 
 Project II. To DISCOVER AND REMEDY ANY HARMFUL EFFECTS OF 
 
 AIR ABOUT THE HOME PREMISES. 
 
 1 . Look for : 
 
 a. Decaying timbers, boards, and trees. 
 
 b. Rusting iron, hinges, fences, screens, tools, and stovepipe. 
 
 c. Tarnishing metal as copper and silver. 
 
 d. Any other changes observed due to air. 
 
 2. To find out the proper way to prevent and to correct the harm. 
 
 3. Apply the remedy. 
 
 39 
 
40 NATURAL RESOURCES OF HOME ENVIRONMENT 
 
 Suggested Projects. 
 
 1. TO PRODUCE AN ARTIFICIAL AIR AND COMPARE ITS PROPERTIES 
 WITH NATURAL AIR. 
 
 2. TO MAKE A STILL AND PRODUCE DISTILLED WATER IN MY 
 HOME LABORATORY. 
 
 3. TO PRODUCE FIRE BY SOME PRIMITIVE MEANS. 
 
 35 
 
 1000 
 
 DensU 
 1 
 
 30000 
 
 What is environment ?- 
 Every boy and girl, yes, and 
 every living plant and animal, 
 no matter where they live, come 
 in contact with certain things in 
 their surroundings. Air is every- 
 where around us. Light is nec- 
 essary to us, so much so that 
 we use artificial light at night. 
 We live either on soil in the 
 country, or if in the city, we 
 come in contact with the hard 
 and often dirty paving stones 
 and sidewalks. Water and food 
 are both necessary. If the tem- 
 perature falls below a certain 
 point, we put on heavier clothes. 
 Heat, then, is evidently a neces- 
 sary factor or part of our sur- 
 roundings. All these things to- 
 gether, air, water, heat, light, 
 food, soil, and the living things 
 that surround us, make up our 
 environment. 
 
 Living in an ocean of air. We are all fully aware 
 every day that air is about us. We live in an ocean of air, 
 
 10 
 
 3-75 
 
 The ocean of air. 
 
LIVING IN AN OCEAN OF AIR 
 
 or, in fact, at the bottom of it. We know that it surrounds 
 us, for does not moving air turn our windmills, blow off our 
 hats, blow out lights, uproot trees, and even wreck houses 
 and whole settlements at times ? 
 
 We know that air occupies space, for if we force an 
 " empty " glass upside down into a pan of water, we find 
 that the water does not 
 enter the " empty " space. 
 We know that air is capable 
 of holding things up. It 
 pushes against our kites. It 
 holds up balloons. It even 
 holds up the moving heavier- 
 than-air machines, or air- 
 planes. The first man who ever flew in an airplane took his 
 simple machine to the crest of a hill, up which a strong wind 
 was blowing. He then launched the glider, for there were no 
 motors used at first in the air, and the force of this air 
 against the flat wings of the machine held him up for a time. 
 
 We may see further evidence that air is a real substance 
 by performing the following experiment. 
 
 Is the glass really empty ? 
 
 Clccnv-p 
 
 Experiment. To show the re- 
 ality of air. 
 
 Materials: Eight-ounce 
 wide-mouth bottle. Two- 
 hole rubber stopper. 
 Funnel. Glass tube. 
 Rubber tube. Clamp. 
 Beaker. 
 
 Method : Arrange the ap- 
 paratus as in diagram. 
 
 Observations and Conclu- 
 sions : When the clamp is 
 closed why does the 
 
42 NATURAL RESOURCES OF HOME ENVIRONMENT 
 
 water remain in the funnel? If the mouth of the tube M is deep 
 in the water when the clamp is opened, and the water runs out of the 
 funnel, what evidence do you see to prove that something is leaving 
 the bottle? 
 
 What air really is. Were any one of us to think over all 
 the possible uses of air, we would probably say its most im- 
 portant use is in the human body, for do we not all use air 
 in breathing? But is breathing anything like burning? 
 Experiments may help us to find this out. If we cover a 
 burning candle with a glass tumbler or cheese dish we 
 notice that the candle goes out in a short time. If we 
 uncover the candle and light it again it will go on burning. 
 If we cover it, it goes out again as before. It is evident that 
 some change takes place in the air during the burning of the 
 candle. Perhaps something in the air is necessary for the 
 burning and it is quickly decreased when we limit the 
 supply of air by inclosing a burning candle in the tumbler. 
 
 We are told by men who have analyzed air that about 99 
 per cent of it is made up of the two gases, oxygen and nitro- 
 gen. If we prepare these gases and study their properties, it 
 may help us to explain the part that the air plays in burn- 
 ing matter and in supporting life and also to show us 
 whether it is the oxygen or the nitrogen which is used 
 in these processes. 
 
 Experiment. To prepare and to observe the properties of the principal 
 
 gases in the air. 
 i. OXYGEN 
 
 Materials: Small wide-mouth bottle or glass. Glass cover. Wood 
 
 taper. Oxone. Candle. 
 
 Method: Drop a piece of oxone about half an inch square into the 
 glass tumbler containing a small amount of water. Light the wood 
 taper. Blow out the flame, leaving a glowing coal at the end. 
 Thrust this into the glass. Name the characteristic property of 
 oxygen shown Will the candle burn in oxygen? 
 
WHAT AIR REALLY IS 
 
 43 
 
 CARBON DIOXIDE 
 
 Materials: Vinegar (or hydrochloric acid). Baking soda (or lime- 
 stone). A glass or beaker. Glass cover. Wood taper. Lime 
 water. Test tubes. 
 
 Method: Pour two tablespocnfuls of vinegar upon a teaspoonful of 
 soda in the glass. Cover immediately. After a minute or two 
 slide the cover to one side and thrust a burning taper into the 
 glass. Produce carbon dioxide in a test tube. Hold the mouth of 
 this tube at an angle over the mouth of a second tube contain- 
 ing some lime water. Carbon dioxide will flow into the lower tube. 
 
 After a minute or two, close the lime water tube with the thumb 
 and shake. This is the lime water test. 
 
 Observation and Conclusion: What characteristic property of carbon 
 dioxide does this show? Result of lime water test? 
 
 NITROGEN 
 
 Materials: Bunsen burner. Test tubes. Rubber stopper. Delivery 
 tube. Shallow dish. Small wide-mouth bottle. Wood taper. 
 Ammonium nitrite. Lime water. 
 
 Method: Heat ten grams of ammonium nitrite in test tube and col- 
 lect Jthe gas by displacement of water as shown in the diagram. 
 When the bottle is full, cover and remove from the water. Open 
 and thrust a burning taper into it. Apply the lime water test. 
 
 Observation and Conclusion: Does nitrogen resemble oxygen or carbon 
 dioxide in its relation to fire? 
 
44 NATURAL RESOURCES OF HOME ENVIRONMENT 
 
 What makes the candle burn ? If we were to place a 
 lighted candle in the jar in which the candle went out 
 (page 42), we would find that it does not burn. Evidently 
 some part of the air caused that candle to burn. Let us 
 try to find out whether it is the oxygen. We have seen 
 that wood burns in oxygen and we guess that it is oxygen 
 that makes it possible for the candle or splinter to burn 
 in the air. Suppose we introduce some oxygen into the 
 glass in which the candle will not burn. After mixing 
 we insert a lighted candle and find that it does burn, act- 
 ing very much as it did in the open 
 air. The mixed gases in the tumbler 
 evidently help the candle to burn. 
 There can now be no doubt that the 
 oxygen of the air is needed to make 
 the candle burn. It is equally es- 
 sential to us in breathing as we shall 
 learn a little later. 
 
 Those of you who have started 
 a home laboratory will be interested 
 to collect oxygen in bottles and to 
 burn other substances in it, as sul- 
 phur and iron. For burning iron 
 use picture cord wire. Unravel the 
 end, warm, dip in sulphur, light 
 the sulphur, and thrust into the jar 
 of oxygen. 
 
 Still another gas in the air. If we were to leave a jar 
 containing limewater in the open air overnight,, we would 
 find in the morning a whitish film on the surface of the 
 liquid. If we prepare a gas by pouring a little vinegar or 
 hydrochloric acid upon cooking soda and pass it through 
 
 The limewater test for carbon 
 dioxide. 
 
WATER IN THE AIR 
 
 45 
 
 limewater, we find that the liquid becomes milky in ap- 
 pearance. If we shake a little limewater in the jar after 
 burning wood or a candle in it, we find that the lime- 
 water turns milky. Evidently we might use this test, 
 known as the limewater test, to prove the presence in 
 the air of a gas formed when 
 certain things are burned. Do 
 you see why ? The chemist tells 
 us that this gas which is pro- 
 duced by mixing soda and vine- 
 gar is carbon dioxide. He uses 
 limewater to test for the pres- 
 ence of carbon dioxide. Carbon 
 dioxide is formed, as we shall find 
 later, by the union of oxygen 
 and a substance called carbon 
 when anything containing car- 
 bon is burned. Carbon dioxide 
 is always present in the air, al- 
 though in very small amounts, 
 about .04 per cent in out-of-door 
 air. It is constantly being given 
 off into the air by decaying vegetable matter, by burning 
 fuels, and by breathing animals. * 
 
 Water in the air. Air is really a very complex sub- 
 stance, and contains besides the gases mentioned, more 
 or less water. You can easily prove this by mixing a 
 little salt with ice in a test tube, and observing the little 
 drops of moisture which form on the outside of the tube. 
 Where does it come from ? In addition to water, several 
 gases, among them argon, are found in small quantities in 
 the air. 
 
 This shows that water is present 
 in the air. 
 
46 NATURAL RESOURCES OF HOME ENVIRONMENT 
 
 There is dust in practically all the air we 
 breathe. 
 
 Impurities in the air. 
 If you allow a beam of 
 sunlight to pass through 
 a small crack into a 
 darkened room, you will 
 see thousands of tiny 
 specks floating in the air. 
 These little particles are 
 perhaps soot, dust, or 
 other bodies. In some 
 cities, like Pittsburgh, 
 
 the smoke is always a constant factor, although it does 
 
 not seem to harm people very much, but where factories 
 
 are numerous, we sometimes get poisonous fumes or gases 
 
 as part of the air we 
 
 breathe. 
 
 Combustion. We 
 
 have seen from the 
 
 experiments we have 
 
 performed that when 
 
 the gas oxygen is 
 
 present, wood or a 
 
 candle may be 
 
 burned. Heat and 
 
 light always accom- 
 pany this burning. 
 
 Combustion or burn- 
 ing in pure oxygen 
 
 is much more intense 
 
 than it is in air. 
 
 Iron and other metals 
 
 can be burned in 
 
 What kinds of oxidation are shown here ? 
 
WATER 
 
 47 
 
 pure oxygen, while in ordinary air the nitrogen dilutes the 
 oxygen and thus weakens its action. 
 
 Oxidation. In the series of experiments we have just 
 performed, burning was simply a union of oxygen with the 
 substances burned, but all around us this union with other 
 substances is taking place without producing any flame. 
 You are all familiar with the fact that iron rusts. This 
 is caused by the union of iron with oxygen. 
 Such oxidation is relatively a slow oxidation. 
 A similar process of oxidation attends the 
 decay of organic matter. In the case of 
 combustion the action is much more rapid, 
 and both heat and light are given off. 
 
 Water. Every boy and girl knows that 
 water is necessary for the life of both plants 
 and animals. This can easily be proved by 
 allowing some living plant to wilt, and then 
 adding a moderate amount of water to the 
 pot in which it grows. What causes the 
 leaves to raise themselves? We say that 
 the plant takes up water. This is true, al- 
 
 . 1-1 Amount of water 
 
 though we cannot at this time explain what in the human 
 happens inside of the plant. Any boy or 
 girl who has had to go without water for several hours 
 knows how necessary it is and how uncomfortable one 
 can be without it. In the World War water played 
 a striking part, especially in General Allenby's campaign 
 against the Turkish army in Palestine. The Turks had a 
 saying that " The Christians will not capture Palestine 
 until the Nile flows into the Jordan." This meant, of 
 course, that they would never capture it, because the 
 Turks believed that such a thing was impossible. But 
 
48 NATURAL RESOURCES OF HOME ENVIRONMENT 
 
 when General Allenby's army marched across the desert 
 into Palestine, the British engineers built a pipe line 
 which actually did carry water from the Nile under the 
 Suez Canal and supplied the army in the desert with 
 fresh, pure water, so the saying of the Turks was carried 
 out almost as if it had been a prophecy. 
 
 No one would think of building a house or locating where 
 there is no supply of water, and modern science has 
 
 shown that pure 
 water is one of the 
 greatest factors in 
 good health. Be- 
 sides using water at 
 home for washing, 
 and sprinkling the 
 lawn, we use it in 
 the form of ice and 
 as steam or hot 
 water to heat our 
 houses, to turn mo- 
 tors which generate 
 power and save la- 
 bor, and in many 
 other ways of which 
 you can think. Why not try to find out how many ways 
 water can be used by man in the home? This would 
 make an excellent home project. But in addition to these 
 uses, the human body needs water, first because a very 
 large percentage of it, about 65 per cent, is made up of 
 water. Furthermore, in order that foods may become part 
 of the body they must first be dissolved in water and soak 
 through the walls of the food tube to become part of the 
 
 Cells are the units of building material in the human 
 body as bricks are of the house. 
 
WHAT IS SOIL? 
 
 49 
 
 blood and in this form go to the various cells or units of 
 building material in the body. In addition to this, water 
 is necessary in order to get rid of the wastes of the body. 
 These wastes must also be dissolved in water and carried 
 off in it, so that water plays an important part in our lives. 
 What is soil ? To the average boy and girl brought 
 up in a large city, the word soil does not mean much. 
 
 Sometimes they may | ; } 1 
 
 play on vacant lots or 
 go to the parks where 
 they see dirt or soil, but 
 they come in contact 
 with it less frequently 
 than the country boy to 
 whom soil means hard 
 work. Gardens depend 
 on soil. They must be 
 weeded and attended 
 to. Crops grow in soil. 
 They must be culti- 
 vated. Fruit trees grow 
 in soil. They require much care. To understand what 
 soil really is and how it came to be, we must look back a 
 great many million years. Long ago, we are told, the earth 
 was a great white-hot mass of rapidly revolving material. 
 As this mass cooled the greater part of it became rock. 
 Later the rock, alternately expanding with heat and con- 
 tracting with cold, began to crack and crumble so that 
 little fragments were formed. These pieces were ground 
 up by the action of ice and running water, and the atmos- 
 phere caused them to decay. Gradually this covering of 
 tiny pieces of rock became soil. Examination of beach 
 
 H.-WHIT. CIV. SCI. IN THE HOME 4 
 
 Formation of inorganic soil. (After Black- 
 welder and Barrows.) 
 
50 NATURAL RESOURCES OF HOME ENVIRONMENT 
 
 sand or river gravel will show you how small particles of soil 
 might thus be formed. 
 
 After plants and animals began to live on the earth, their 
 dead bodies, upon decaying, became a part of the soil. 
 Any boy who has been in a forest knows that the soil is 
 covered with dead leaves, decaying wood, and the like. 
 He also knows that if he digs down through the tangled 
 
 Formation of organic soil or humus. (U. S. Forest Service.) 
 
 mass of roots and other materials forming black rich soil, he 
 may at last come to sand or to crumbling rock. 
 
 Soil and the home. Soils play a very important part 
 in the health of our home. If the soil is of sand and not 
 clay, water will drain readily, and we shall not be troubled 
 with standing bodies of water after rains. Our garden 
 will grow better and conditions of drainage will be good. 
 We shall later see that the fertility of the garden depends 
 largely upon the kind and composition of soil, and this 
 means that the home grounds may or may not be attrac- 
 
THE SUN AND RAYS OF HEAT 
 
 tive, depending on the kind of soil. We shall find later that 
 the soil of the garden or lawn, instead of being dead as we 
 thought, is really a battlefield in which millions of little 
 germs are engaged, some in causing decay of materials 
 there, others in making the decaying material available or 
 valuable for plants in the form of nitrogen compounds, 
 while still others 
 break down these 
 nitrogen compounds 
 and allow some of 
 the nitrogen to pass 
 off into the air. 
 
 Light and heat. 
 What would you do 
 without light? We 
 must all realize the The effect of light upon a growing plant 
 
 importance of light when we remember how much artificial 
 light means to us in our homes. All green plants need 
 light. Notice the geranium or oxalis growing in your win- 
 dow garden. The stems turn to the light, and expose as 
 much leaf surface as possible to the sun's rays. Without 
 light no green plant can exist, and without green plants 
 no animals can exist. Think this over and see if it is not 
 true. Your beefsteak came from a cow which lived upon 
 grass which grew as a result of having, among other things, 
 sunlight. . You know, too, there can be no life without 
 heat. 
 
 The sun and rays of heat. Have you ever stopped to 
 think why it is warmer in summer than in winter ? A glance 
 at the diagram on page 52 will show you. The sun's 
 rays come more directly upon us in summer, and give us 
 more heat. If you do not believe the sun gives off heat, 
 
52 NATURAL RESOURCES OF HOME ENVIRONMENT 
 
 use a burning glass on your fingers instead of on a piece 
 of paper. This heat or energy is more useful than we at 
 first are aware. Energy is the power to do work. The sun 
 
 How the sun's position varies throughout the year. Does it help explain our cold 
 winters and warm summers ? (After Todd.) 
 
 works for us in many ways, and the most wonderful of 
 all is the making of food by green plants. The length of time 
 that the sun works for us depends upon the section of 
 
 Notice that the beam of sunlight covers a smaller area of the earth's surface at noon 
 than at any other time. 
 
 the country in which we live. Study the sunshine chart 
 to see how much sunshine you have in your own locality. 
 
FOODS 
 
 53 
 
 Foods. Another resource of our environment is food. 
 We know that when we are hungry we eat, but we cannot 
 tell why, nor can we tell what the foods do for us. This 
 will be the subject of a later lesson. All we need to know 
 now is that these foods which are taken into our bodies 
 may be used for two purposes, to build more body material, 
 and to release energy or work power in the body. We grow 
 
 up to about the age of twenty, and may increase in weight 
 after that, but it is not easy for us to realize that the 
 food we take into our bodies must actually be oxidized or 
 burned in order to release energy or work. But if we think 
 back to one of our former experiments, this is not so diffi- 
 cult to understand. You remember that when limewater 
 turned milky, it was a test that carbon dioxide had been 
 released, or that something containing the element carbon 
 had been oxidized. If we expel air from our lungs into a 
 jar of limewater we notice that in a very short time the 
 
54 NATURAL RESOURCES OF HOME ENVIRONMENT 
 
 limewater becomes milky in color. From former experi- 
 ments, it is evident that oxidation must be taking place in 
 our bodies. It would not require much of a stretch of one's 
 imagination to think out this whole process, and in this way 
 compare our own bodily machine to that of an engine. 
 Coal may be the source of power to drive the engine. In 
 the case of our bodily machine, what is it that corresponds 
 to the coal of the mechanical machine? 
 
 Scoring my environment. The following score card is 
 a tentative project. We shall find much in the future chap- 
 ters of this book and its companion book on Civic Science in 
 the Community that may cause us later to wish to change 
 our score. You may think of other items to score that seem 
 more important to you. If so, make a score card of your 
 own. Modify any of the conditions here that you think 
 ought to be changed and bring your suggestions into class 
 as a problem for discussion. Get help at home where you 
 need it on this card and above all, try to be honest in 
 your estimates. Remember you do not cheat anybody 
 but yourself in a score which you know is incorrect. 
 
 REFERENCE BOOKS 
 
 Barber, First Course in General Science, Chapter II. Henry Holt and Company. 
 
 Blackwelder and Barrows, Elements of Geology. American Book Company. 
 
 Caldwell and Eikenberry, General Science, Chapters II, VI, VIII. Ginn and 
 Company. 
 
 Clark, Introduction to Science, Chapter IV. American Book Company. 
 
 Dorrance, The Story of the Forest. American Book Company. 
 
 Hunter, Laboratory Problems in Civic Biology, Chapter II. American Book Com- 
 pany. 
 
 Smith and Jewett, Introduction to the Study of Science, Chapter II. The Macmillan 
 Company. 
 
 Trafton, Science of the Home and Community. The Macmillan Company. 
 
 Van Buskirk and Smith, The Science of Everyday Life, Projects II, III, IV. Hough- 
 ton Mifflin Company. 
 
 Weed, Chemistry in the Home, Chapters II, VII, IX. American Book Company. 
 
SCORING MY ENVIRONMENT 
 
 55 
 
 SCORE CARD. THE NATURAL RESOURCES OF MY ENVIRONMENT 
 
 
 EXCELLENT 
 
 FAIR 
 
 VERY POOR 
 
 MY SCORE 
 
 
 Total 
 
 AIR 
 
 Air pure 
 No dust (2) 
 No smoke (2) 
 No bacteria (2) 
 
 No odors (2) 
 
 Much vegetation 
 in vicinity (2) 
 
 Air contains dust at 
 times (i) 
 Some smoke (i) 
 Some bacteria (i) 
 Some odor or dan- 
 gerous fumes (i) 
 Parks (i) 
 Public play- 
 grounds (i) 
 
 Air has much dust (o) 
 
 Smoke at all times (o) 
 Many bacteria in 
 air (o) 
 Much odor or poison- 
 ous fumes (o) 
 No parks or play- 
 grounds (o) 
 
 
 
 WATER 
 
 (City boy 
 and girl 
 score 10 
 if in a 
 city with 
 good 
 protected 
 water 
 supply) 
 
 Spring or well 
 tested by bac- 
 terial expert; 
 driven or ar- 
 tesian well; all 
 protected at 
 'surface (8) 
 Rain water pro- 
 vided in cement 
 cistern; no 
 vegetable mat- 
 ter in supply (2) 
 
 Spring or well not 
 recently tested. 
 Protected by 
 cement curbing. 
 No privy or cess- 
 pool within 100 
 ft. (4) 
 Rain water in tank 
 or barrel; no ce- 
 ment (i) 
 
 Spring or well not 
 properly protected. 
 Cesspool or privy 
 within 100 ft. (o) 
 
 No rain water, or bar- 
 rel open with wig- 
 glers in it (o) 
 
 
 
 SOIL 
 
 (City girl 
 and boy 
 score 10 
 if living 
 in apart- 
 ment) 
 
 Soil; sandy loam 
 (3) 
 House high, 
 drainage from 
 house (3) 
 No pools or 
 standing water 
 (2) 
 Cellar always 
 dry (2) 
 
 Soil; sandy and dry 
 or part clay (2) 
 House level with 
 street, drainage 
 fair (2) 
 Pools of water 
 sometimes after 
 rain (i) 
 Cellar sometimes 
 damp (i) 
 
 Soil; clay (o) 
 
 Drainage poor, house 
 below street level (o) 
 
 Standing water after 
 rain (o) 
 
 Cellar always wet (o) 
 
 
 
 WEATHER 
 
 Sunlight 50% of 
 the time (4) 
 Temperature 
 rarely over 95 
 or under 
 
 -20F. ( 3 ) 
 
 No damaging 
 floods or severe 
 drouth (3) 
 
 Sunlight 40% of 
 the time (2) 
 Temperature rarely 
 above 100 or be- 
 low 30 F. (2) 
 
 Occasional damage 
 by floods or 
 severe drouths (i) 
 
 Sunlight under 40% 
 of the time (o) 
 Temperature rarely 
 more than 105 or 
 below 40 F.(o) 
 
 Frequent damage 
 from floods or 
 drouths (o) 
 
 
 
 FOODS 
 
 Home supply of 
 fruits, vege- 
 tables, eggs, 
 and poultry (5) 
 Food purchased 
 reaches home 
 in sanitary con- 
 dition and 
 fresh (3) 
 Foods relatively 
 cheap (2) 
 
 Home supply of 
 either fruits and 
 vegetables or eggs 
 and poultry (3) 
 Food purchased _ 
 reaches home in 
 fair condition, 
 not always fresh 
 d) 
 Foods moderate in 
 cost (i) 
 
 No home supply of 
 foods; no garden, 
 or chickens kept (o) 
 
 Foods neither sani- 
 tary nor fresh (o) 
 
 Foods expensive (o) 
 
 
 
 GRAND TOTAL 
 
 NOTE: You are expected to pick out the items that you think cover your conditions and 
 score under proper column. For example, if food supply was all purchased but was sanitary, 
 fresh, and cheap, you would score (o), (3), and (2) respectively. Do not fill m the above 
 blank, but make a similar score card in your notebook. 
 
PART II. GOOD HEALTH IN THE 
 
 HOME 
 
 CHAPTER IV 
 PURE AIR 
 
 Problems. i. To understand how and why we breathe 
 air. 
 
 2. To understand the need of ventilation and how to ven- 
 tilate our rooms. 
 
 Experiments. i. Does air have weight? 
 
 2. To illustrate the process of breathing. 
 
 3. To determine some products of respiration. 
 
 4. To demonstrate .the principles involved hi ventilation. 
 
 Project I. CAN I INCREASE MY LUNG CAPACITY WITHIN TEN 
 
 WEEKS ? 
 
 1. What is my chest expansion at the present time? 
 Take measure under the arms, clothing removed. 
 
 (1) After taking a good normal breath. 
 
 (2) After exhaling a normal breath. 
 
 (3) After filling the lungs as full as possible. 
 
 (4) After forcing all the air possible from the lungs. 
 The difference between (3) and (4) is the chest expansion. 
 
 2. Make a tabular form for recording these four measurements 
 and the chest expansion. Take weekly measurements for ten weeks. 
 
 3. Find out what exercise is good to develop the lungs and prac- 
 tice it faithfully each day. 
 
 56 
 
PROJECTS 57 
 
 4. From the weekly reports kept make a graph to show the 
 changes in your chest expansion during the ten-week period. 
 
 Make a report explaining what exercises you have used, and in- 
 clude tables and graph. 
 
 Have you experienced any ill effects or any beneficial effects from 
 this work? 
 
 Note : If desired, actual lung capacity may be tested with a spirometer, 
 though the measurements suggested give satisfactory results. 
 
 Project II. How TO SECURE PURE AIR IN MY BEDROOM. 
 
 1. What methods are used in ventilating ? 
 
 How do my friends ventilate their rooms, windows open at 
 top, at bottom, at both top and bottom; two windows open? 
 Open doors to help air circulation. Dust annoyance. Advan- 
 tage and disadvantage of thin muslin or cheesecloth windows. 
 Deflecting devices. Screens in room to deflect drafts. 
 
 2. Need of fly and mosquito screening the entire length of win- 
 dow. 
 
 3. Plan of room showing arrangement of essentials. 
 Indicate with arrows probable movement of air. 
 Effect of winds; direction of wind; no winds. 
 
 4. Make a complete report of your investigation, illustrating with 
 diagrams, clippings, and pictures from papers and magazines. 
 
 Give specifically best plan for ventilating your own bedroom. 
 
 Project III. To PREPARE FOR LIFE SAVING WHERE ARTIFICIAL 
 
 RESPIRATION MUST BE USED. 
 
 1. You must qualify as a good swimmer. 
 
 2. You must understand dangers from "live" electric wires, 
 and how to remove the shocked person from such wires. 
 
 3. You must know how to rescue a person in water. 
 
 4. You must be able to use the Shaefer method of artificial res- 
 piration. 
 
 Reference: American Red Cross Abridged Textbook on First Aid, 
 Blakiston, or Boy Scout Manual. 
 
 When you feel qualified for this work, write a report on what 
 you can do, and how you would act in case of accident requiring 
 artificial respiration. 
 
PURE AIR 
 
 Suggested Project. 
 
 I. TO MAKE A SUBSTITUTE FOR THE SPIROMETER WHICH YOU 
 CAN USE IN TESTING YOUR LUNG CAPACITY. 
 
 Thought Questions. 
 
 1. Do you breathe normally immediately after holding the 
 breath as long as possible ? 
 
 2. Can you " hold your breath " longer with lungs inflated or 
 deflated? Why? 
 
 Why is pure air necessary ? This is an age when people 
 seem to recognize the necessity of pure air for healthy liv- 
 
 ing. People build houses with sun 
 
 parlors open to the air, and with 
 sleeping porches where the entire 
 family may sleep winter and sum- 
 mer. New laws require city houses 
 and tenements to be built with an 
 adequate air space so that sleeping 
 rooms may have a proper amount 
 of air going in through the windows 
 at night. We have outdoor school- 
 rooms and both teachers and doc- 
 tors preach the need of proper 
 ventilation. 
 
 It seems almost incredible that 
 over sixty barrels of air pass in and 
 out of your lungs every day of 
 your life. If you will count the 
 number of breaths you take in a 
 minute while you sit quietly in the schoolroom (number of 
 tunes your chest rises and falls), and then if you will exer- 
 cise vigorously for two minutes (a stationary run with hands 
 raised above the head will be a good exercise) and again 
 
 An out-of-door sleeping porch. 
 
AIR PRESSURE AND WHAT IT IS 
 
 count the number of times you breathe in one minute, you 
 will notice a distinct increase. Compare this with the 
 forced draft in the engine. Evidently the body needs 
 more air when we exercise than when we sit quietly, and 
 this wonderful human machine responds automatically to 
 its demands. 
 
 Air pressure and what it is. We are told that air presses 
 down on us with a force of fifteen pounds to the square 
 inch. It is easy to understand that water exerts pressure 
 on a vessel which contains it, but it is more difficult to think 
 of air as having weight and so exerting pressure. We may 
 actually see in an experiment whether or not air has Weight 
 by weighing a bottle before and after pumping air out 
 of it. 
 
 Experiment. Does air have weight? 
 
 Materials: A two-liter bottle with one-hole rubber stopper. Glass and 
 rubber tubing. Burette clamp. Mohr clamp. Platform scales. 
 Sand or weights. Air 
 pump for suction or _ 
 
 compression. Vase- ^= ^5^=3 ^ 
 line. 
 
 Method and Observa- 
 tions: Pass the glass 
 tube through the rub- 
 ber stopper and at- 
 tach a rubber tube to 
 it. Place the Mohr 
 clamp on the rub- 
 ber tube. Set the bottle on one arm of the platform scales and 
 fasten the rubber tubing to a clamp on a ring stand leaving the tubing 
 loose enough to move freely up and down with the movement of the 
 balance. Make the stopper tight with vaseline and tie it in if air is 
 to be forced into the bottle. Exactly balance the bottle by pouring 
 sand into a jar or using weights on the other balance arm. 
 
 By means of a force pump attached to the end of the rubber tube force 
 air into the bottle. What is the evidence to show if air has weight? 
 Disconnect the pump to open the tube to the air. Result? 
 
6o 
 
 PURE AIR 
 
 \foice- box: 
 
 How we breathe. We all know that somewhere inside 
 of our bodies there are spongy structures we call lungs. 
 The diagrams (page 70 and below) show us that from the 
 mouth cavity down the front of the neck leads a tube known 
 as the air tube, or windpipe, and that this tube branches 
 into two pipes, or bronchial tubes, which in turn branch 
 
 again and again and 
 end in tiny grapelike 
 clusters of little air 
 sacs, which are too 
 small to be seen with 
 the naked eye. In 
 these air sacs, which 
 have extremely thin 
 walls, the oxygen of 
 the air comes in con- 
 tact with the blood, 
 the blood taking 
 some oxygen and 
 giving up in return 
 some carbon diox- 
 ide, which has been 
 brought there from 
 the various parts of the body where work is being done. 
 Around these delicate lungs are placed the ribs, so that as 
 the diagram shows, the two lungs are held within a sort 
 of bag or cavity. This chest cavity is bounded at the 
 bottom by a muscular wall, the diaphragm, which extends 
 across from the front to the back of the body, and makes 
 an air-tight surface surrounding the lungs. If we now study 
 a simple piece of apparatus shown in the picture on the next 
 page, we shall be able to understand how we breathe. 
 
 The human breathing organs. Notice one lung is cut 
 open to show the air sacs. 
 
HOW WE BREATHE 
 
 61 
 
 Experiment. To illustrate the process of breathing. 
 
 Materials: A bell jar fitted with a rubber cork, and wide glass tubing 
 from the ends of which are tied two rubber balloons. Over the lower 
 end of the bell jar is tied a piece of sheet rubber such as dentists use, 
 with a piece of string attached at the middle outside the jar. 
 
 Method: Pull on the string so that the cavity inside the jar is increased 
 in size. What effect does this have on the rubber balloons ? Allow the 
 rubber diaphragm to go back to its former position by releasing the 
 tension of the string. What happens to the balloons? Why? 
 
 Conclusion: Explain the different actions you have seen and apply 
 them to the action of breathing. If your finger were placed on the 
 tube leading into the balloons and then the rubber diaphragm were 
 pulled, do you think the action would be the same ? Try it. 
 
 It is very evident from 
 this experiment that the 
 air pressing in on the bal- 
 loons through the tube 
 causes them to expand. 
 If we now compare this 
 apparatus in its working 
 with our own lungs, ribs, 
 and diaphragm, we are 
 able to understand how 
 we breathe. If you will 
 stand upright and take 
 a full deep breath, you 
 will readily notice that 
 as your chest expands 
 the ribs rise. This makes 
 
 Apparatus to show the mechanics of breathing. 
 
 the chest cavity some- 
 what larger. As the ribs rise the muscular diaphragm 
 assumes a straighter line. The lungs lying in this cavity 
 are now filled by the air which rushes into the larger 
 space thus made. This enlargement of the chest cavity 
 
62 
 
 PURE AIR 
 
 and the consequent filling of the lungs with air is known 
 as an inspiration. After we have raised the ribs, we al- 
 low the muscles which pull them up to relax ; as the ribs 
 sink back and the diaphragm expands curving up into 
 the chest cavity, the chest cavity becomes smaller and 
 pushes the air from the lungs. This is an expiration. 
 
 Distinction between breathing and cell respiration. 
 Most boys and girls think that breathing takes place in 
 
 the lungs. This is 
 true, but we would 
 soon die if the oxygen 
 stopped there. As a 
 matter of fact the 
 lungs are simply or- 
 gans which serve to 
 pass oxygen over to 
 the blood and to take 
 carbon dioxide and 
 waste matter from it. 
 The real respiration 
 takes place in the cells of the body which do work for 
 us. If we work the muscle of the arm, then that muscle 
 in order to do its work must oxidize some fuel or food 
 material which has been carried to it by the blood. If 
 we work with the brain, then food must be oxidized in 
 the brain cells in order that energy may be released there. 
 The blood, like a railroad train, carries the oxygen from the 
 lungs to all places in the body where oxygen is needed. 
 In the blood are little cells known as red corpuscles. These 
 cells have the peculiar ability to carry oxygen. They are 
 also able to give up this oxygen where it is needed in the 
 body. Thus the blood becomes a medium of exchange 
 
 The respiration of cells. 
 
THE NECESSITY FOR DEEP BREATHING 
 
 between the cells which need oxygen and the air which is 
 taken into the lungs. The products formed when oxygen 
 is used in the body are exhaled in the breath and may be 
 detected by simple tests. 
 
 Experiment. To determine some products of respiration. 
 
 Materials: Glass tubing. Limewater. Test tube. 
 
 Method and Observations: Blow the breath through a large, dry glass 
 tube until there is evidence of material deposited. From its appear- 
 ance what do you judge this to be? Blow the breath through lime- 
 water in a test tube for a short time. What change occurs? Recall 
 the meaning of this test, which was previously shown in Chapter III. 
 
 Conclusion: What are two substances produced in our bodies which 
 escape in our breath? 
 
 The necessity for deep breathing. The blood, too, 
 carries back to the lungs carbon dioxide which has been 
 formed in the cells 
 as a result of the 
 work done there, and 
 this carbon dioxide, 
 as we have seen by 
 our limewater test, 
 is expelled from the 
 lungs during respira- 
 tion. The lungs dur- 
 ing ordinary breath- 
 ing do not expel 
 more than one sev- 
 enth of their total 
 load of air. More 
 of the air in the 
 
 Tidal air is that air taken in and expelled during ordi- 
 nary breathing. Complemental air is what we can 
 take in, in addition to tidal air in a full deep breath. 
 Reserve air is what we can force out in addition to 
 tidal air by forced expiration. Residual air is that 
 which always remains in the lungs. 
 
 air in 
 
 lungs can be expelled when we take a deep breath, but 
 there is always some air left in the lung sacs known as 
 residual air. This air must be very impure, as it lacks 
 
64 PURE AIR 
 
 oxygen and has much carbon dioxide and other waste 
 products as well. It is therefore highly important that 
 we force out as much of this air as possible rather frequently, 
 and we can do this only by deep breathing. One of the 
 best deep-breathing exercises, which should be practiced 
 several times daily out of doors, is to raise the arms well 
 from the sides and breathe deeply while we do this, hold 
 the breath for three seconds, exhale, and repeat fifteen 
 times. 
 
 Water, carbon dioxide, and other wastes given off 
 through the lungs. A study of chemistry shows that as 
 wood, which contains carbon and hydrogen, combines with 
 oxygen it produces two substances, carbon dioxide and 
 water. A chemist writes these two substances as CO 2 
 (carbon dioxide) and H 2 O (water) . Chemical elements are 
 very simple substances of which oxygen, hydrogen, and 
 carbon are examples. They always unite in definite propor- 
 tions. For example, water is always composed of f hydro- 
 gen and ^ oxygen by volume, no matter how much of it 
 there may be. Foods contain carbon, hydrogen, and 
 oxygen, and when they are oxidized in the body, produce other 
 substances ; among these are carbon dioxide and water. You 
 are, perhaps, familiar with the odor that is noticed when 
 one passes from out of doors into a closed room where sev- 
 eral people have been for some time. The " stuffy " odor 
 is caused, in part at least, by certain waste materials which 
 have been passed off through the lungs and skin into the air. 
 
 Need of ventilation. It therefore becomes necessary 
 in rooms where people are gathered, such as schoolrooms, 
 churches, " movie " theaters, and the rooms of our own 
 homes, to have the air constantly changed in order to 
 get rid of the odor, moisture and carbon dioxide, and 
 
NEED OF VENTILATION 
 
 to supply fresh air with its greater load of oxygen in 
 their place. We must not think that in breathing we use 
 all of the oxygen from the room. This would be impossible. 
 Neither does the carbon dioxide given out from the lungs 
 make the air unfit to breathe. Recent experiments have 
 shown that man can live in 
 an atmosphere containing 
 only ten per cent oxygen, an 
 amount so small that a match 
 could not burn in it. But 
 you are all familiar with the 
 great feeling of discomfort 
 one has in a closed and 
 "stuffy" room. This dis- 
 comfort is due principally to 
 the increase in humidity, or 
 water content of the atmos- 
 phere, in the room. Circu- 
 lation of the air will to a 
 certain extent prevent this 
 discomfort. This circulation 
 may be brought about by 
 electric fans, blowers, etc., 
 in large rooms, or by proper ventilation by means of 
 windows in smaller rooms. On the other hand, water 
 in the atmosphere is absolutely necessary for health. 
 In most artificially heated rooms the air is far too dry 
 for health, as people who live in such rooms take cold 
 more easily when they go out of doors. Air may be kept 
 moist by keeping pans of water on the radiators and 
 registers. There is a certain amount of natural circulation 
 due to the difference in weight of hot and cold air. 
 
 H.-WHIT. CIV. SCI. IN THE HOME 5 
 
 This shows the direction of air currents 
 when it is warmer indoors than out. 
 Can you account for this ? 
 
66 
 
 PURE AIR 
 
 Let us now try an experiment to show how to ventilate 
 properly as a basis for home study. 
 
 Experiment. To demonstrate the principles involved in ventilation. 
 Materials: A ventilation box. This is to be about 20 inches tall, 2 feet 
 long, and 4 inches thick, having one of its large surfaces of glass. Either 
 the front or back should be grooved to facilitate opening. A slanting 
 
 shelf one inch wide runs 
 from one lower corner 
 nearly to the opposite 
 upper corner. One-inch 
 holes are bored in the 
 sides and top as sug- 
 gested by the letters A 
 to F in the diagram. 
 Corks are used to close 
 these holes. Three small 
 candles are placed on 
 the diagonal shelf 
 equally spaced so that 
 they are at different 
 levels. 
 
 Method and Results: (i) Light the three candles. Close all the open- 
 ings. Which candle goes out first? Explain why. (2) Light the 
 candles. Open holes B and C. Test currents of air by holding 
 smoking joss stick or rolled paper at the openings. Result? (3) Re- 
 peat (2), using holes A and D open. (4) Repeat, using D and C open. 
 (5) Repeat, using A and B open. (6) Repeat, using E and F open. 
 Conclusions: What facts about circulation of air are shown by the experi- 
 ments? What facts about changes in air due to burning substances? 
 What facts are indicated which will be helpful in planning circulation 
 of air in our homes? What conditions found in the experiment are 
 not duplicated in a room where we wish to apply the principles of 
 ventilation? In what particulars can we apply the results found here 
 to ventilation of rooms where people are congregated? Is ventilation 
 needed for any other reason than the fact that a part of the oxygen 
 of the air has been consumed? 
 
 Dust and its dangers. Not very many years ago an 
 eminent New York physician wrote a book entitled " Dust 
 
 A ventilation box. 
 
DUST AND ITS DANGERS 
 
 and its Dangers." The dangers, as he pointed out, are 
 not in the dust itself, but in the possible presence in the 
 dust of many tiny living organisms known as bacteria, 
 yeasts, or molds. It is very easy to prove the presence of 
 these living plants, for such they are, in the air of the school- 
 room. Let us obtain some previously prepared material 
 known as cul- 
 ture medium. 1 
 This has been 
 placed in a Petri 
 dish, a small 
 glass dish with 
 a loosely fitting 
 glass cover. The 
 dish and con- 
 tents have been 
 t h o r o ug h ly 
 sterilized, or 
 rendered free 
 from all living 
 
 * Plate culture exposed for five minutes in a school hall 
 
 of h P a tin & where pupils were passing to recitations. Each spot is 
 
 o ' a colony of bacteria or mold. 
 
 Thus we know 
 
 that the culture medium and everything inside of the dish is 
 dead. If this dish is now opened for five minutes, exposing 
 the surface of the culture medium to the air of the room, then 
 closed and put away in a warm dark place for two or three 
 days, a number of little dots of different sizes and colors will 
 be found growing on the surface of the culture medium (see 
 
 1 This culture medium may be bought already prepared. It is a gela- 
 tine or agar-agar preparation upon which germs grow readily. It has been 
 previously rendered free from all living things by sterilization. 
 
68 
 
 PURE AIR 
 
 illustration) . These little masses of material have not grown 
 from nothing. They increase in size day by day. They must 
 be alive. Since everything in the dish was dead, we have 
 to conclude that they came from the air. If we were to 
 examine the material under a very high-power microscope, 
 we would find it composed of millions upon millions of tiny 
 plant forms known as bacteria or m"olds. These tiny plants 
 
 DfcY BROOM 
 
 DAMP BROOM 
 
 CARPET SWEEPER, 
 
 VACUUM CLEAN CK> 
 
 Which of the above methods is the best ? What evidence is shown ? 
 
 grow and thrive in our homes under conditions which we 
 shall investigate more thoroughly later. 
 
 Proper methods of sweeping and dusting. If these 
 germs are present in dust, then it is important for us to 
 have methods of sweeping and dusting which will not raise 
 dust. A good home project for girls and boys would 
 be the working out of the best methods for cleaning their 
 own homes. If we are fortunate enough to have electricity, 
 then an electric vacuum cleaner which sucks up the dust 
 
HAY FEVER 
 
 69 
 
 and dirt without charging the air with it is the best method. 
 Floors should be wiped with a damp or oily cloth rather 
 than swept. Why? An interesting problem would be 
 this : To determine which method of cleaning in the 
 home is the most hygienic. Suggest four methods of clean- 
 ing and consequently four different conditions under which 
 you could expose prepared Petri dishes in your own home. 
 
 How the organs of respiration are protected from dust. 
 The nose, the organ of smell, performs several other very 
 important offices. Just near its entrance are 
 many hairs which the air must pass. Down 
 below, in the throat itself, is a soft lining of 
 cells which are provided with tiny whip-like 
 structures made of living matter. These 
 structures, called cilia, are constantly in mo- 
 tion, and always whip upwards so as to ex- 
 pel all foreign material from the lungs. The 
 ciliated cells, together with the hair in the 
 nose, prevent most foreign matter, such as dust 
 and dirt with their load of germs, from going 
 down into the lungs. The lining of the nose also moistens 
 and warms the air before it passes to the lungs. 
 
 Hay fever. Dust, however, often causes us trouble. 
 The disease known as hay fever seems to be caused by dust 
 made up of pollen from different kinds of flowers. This 
 pollen is a violent poison to some people, and causes 
 sneezing, itching eyes and nose, and a feeling of dis- 
 comfort. Sometimes relief is obtained by means of spray- 
 ing the air passages, or plugging the holes in the nose with 
 medicated absorbent cotton, but so far no real cure has 
 been found except by inoculation with various vaccines 
 made from the agents which cause the trouble. 
 
 The tubes lead- 
 ing into the 
 lungs are pro- 
 tected from 
 dust by means 
 of ciliated 
 cells. 
 
PURE AIR 
 
 AcLe-noicl 
 Growth.3 
 
 Diseases of the air passages. We are probably more 
 aware of diseases of the air passages than almost any other 
 part of the body. Nearly everybody has a cold at one 
 time or another, and we have all heard of and perhaps 
 suffered from ravages of influenza and pneumonia. Other 
 diseases which unfortunately attack the air passages are 
 diphtheria, tonsillitis, laryngitis, pharyngitis, bronchitis, 
 
 catarrh, croup, and 
 whooping cough. 
 
 Adenoids and tonsils. 
 Tonsils often make 
 much trouble for us. 
 Germs lodge and grow 
 in them and cause many 
 diseases. Infected ton- 
 sils should be removed. 
 Polyps are soft jellylike 
 growths in the nose 
 which cause stuffiness, 
 difficulty in breathing, 
 and thickness of voice 
 in children. If present, 
 they should be removed 
 by a physician, as the 
 loss of the sense of smell, as well as much discomfort, may fol- 
 low. Adenoids are almost always accompanied by breathing 
 through the mouth, snoring at night, and general listlessness 
 and indifference to work and play. Adenoids grow in the 
 back part of the nose, and shut off the air supply through this 
 organ. They should be treated, or removed if very large. 
 
 Artificial respiration. Accidents which shut off the 
 supply of oxygen, are drowning, suffocation from gas, 
 
 Section of head and neck showing position of 
 adenoids and tonsils. 
 
ARTIFICIAL RESPIRATION 
 
 7 1 
 
 stoppage of the nose or throat, and electric shock. In 
 case of any accident in which breathing stops, it is neces- 
 sary to work quickly. Send for a doctor at once. The 
 person should be taken into the open air if possible, the 
 clothes loosened, and artificial respiration started as soon as 
 possible. In the case of drowning, the first thing to do is to 
 get the water out of the lungs and air passages. - To do this 
 we must raise the 
 lower part of the 
 body of the patient 
 from the ground so 
 that the water may 
 run out. Lift the 
 patient up quickly 
 two or three times 
 with a jerk, with the 
 arms underneath the 
 abdomen. Do not 
 take more than half 
 a minute to do this. 
 Water from the 
 lungs will thus be 
 forced out. Then 
 at once place the patient on the ground face down, arms 
 outstretched, and with head on one side so that air can 
 get in through the nose and mouth. Place yourself 
 astride of the patient, but without resting any weight 
 on him. Place the palms of your hands across the 
 small of his back, thumbs touching. Then allow your 
 weight to fall on your wrists by bending your body for- 
 ward. This decreases the size of the patient's chest cavity 
 and forces air out of his lungs. Now release the pressure 
 
 Shaefer method of artificial respiration. 
 
72 PURE AIR 
 
 by swinging backward quickly. The elastic chest of the 
 patient will go back to its original position, thus drawing 
 air into the lungs. Perform these motions about fourteen 
 or fifteen times a minute, and keep it up for several hours, 
 if necessary, for* victims of drowning accidents have been 
 brought back to life after hours of patient work. If there 
 are others to help have them rub the arms and legs toward 
 the body, as this helps the circulation, and as soon as possi- 
 ble cover with warm blankets. As the patient gets better, 
 give him warm drinks and place hot water bags at the hands 
 and feet. Keep a crowd away from the patient, as he needs 
 all the air he can get. 
 
 In case of suffocation, where the patient has lost con- 
 sciousness, start artificial respiration as directed above, and 
 send at once for a doctor. In case of electric shock the 
 patient must first be rescued. Remember that live wires 
 transfer their electricity through the body of the victim. 
 It is necessary to stand on dry wood, cloth, or rubber, and 
 then you should not touch the person you are rescuing with 
 your hands. You may be able to remove the wire with 
 a dry piece of wood, or cut it with an ax having a dry 
 wooden handle. If the vie tun lies on the wire, place coats 
 under his head and feet and lift him off. As soon as you 
 have rescued the victim start artificial respiration at once, 
 for time is a very important factor here, especially if he 
 has become unconscious. Treatment for lightning shock is 
 the same as for electric shock. 
 
 Fainting. A fainting attack is brought on by a de- 
 crease in the amount of blood in the brain. A person 
 feeling dizzy should lie down with the head lower than 
 the body. This will usually prevent fainting and will 
 hasten the return to consciousness of one who has 
 
REFERENCE BOOKS 
 
 73 
 
 fainted. Abundant fresh air and loose clothing are helps. 
 Enforced respiration often shortens an attack. Respi- 
 ration may be 
 stimulated by 
 throwing cold 
 water upon the 
 face and chest. 
 Ammonia may 
 also be inhaled, 
 but avoid letting 
 any drop into 
 the eye or irri- 
 tating the air 
 passages unduly 
 by holding it too 
 near the mouth 
 
 or nose. 
 
 Why is the head lower than the rest of the body ? 
 (After Tolman.) 
 
 REFERENCE BOOKS 
 
 Allen, Civics and Health, Chapters V, VI (For teacher). Ginn and Company. 
 
 American Red Cross Textbook on First Aid. Blakiston's Son and Company. 
 Broadhurst, Home and Community Hygiene, Chapters IX, XI (Teacher's use). 
 
 J. B. Lippincott Company. 
 
 Chapin, Sources and Modes of Infection (Teacher's use). J. B. Lippincott Company. 
 Fisher and Fisk, How to Live, Chapter I (Advanced readers). Funk and Wagnalls 
 
 Company 
 Hill, The New Public Health, Chapters III, IX, XV (Teacher's use). The Mac- 
 
 millan Company. 
 
 Hough and Sedgwick, The Human Mechanism. Ginn and Company. 
 Hunter, A Civic Biology, Chapters XXI, XXII. American Book Company. 
 Hunter, Laboratory Problems in Civic Biology. American Book Company. 
 Lee, Health and Disease, Chapters VIII, XII (Teacher's use). Little, Brown, and 
 
 Company. 
 
 New York State Ventilation Commission Reports (Advanced readers). 
 
 Prudden, Dust and Its Dangers. G. P. Putnam's Sons. 
 
 Ritchie, Primer of Sanitation, Chapters XX, XXI. World Book Company. 
 
 Woods Hutchinson, Preventable Diseases. Houghton Mifflin Company. 
 
CHAPTER V 
 WATER IN THE HOME 
 
 Problems. i. To understand the cycle of water in 
 nature. 
 
 2. What are the available sources of a home water supply? 
 
 3. How can you tell safe from unsafe water? 
 
 4. How can water be brought into the home ? 
 
 5. What is a "solution"? 
 
 Experiments. i. To find a method of purifying water (distillation). 
 2. To determine how air pressure can lift water. 
 
 Project I. To MAKE A LIFT PUMP. 
 
 Plan how you can make a working model of a lift pump or a force 
 pump. 
 
 Suggestions. Large glass tubing and cylindrical lamp or gas 
 chimneys make good pump barrels. Valves are easily made by 
 using sheet rubber with a long tack or pin passing through it. 
 
 Your report should contain at least two good diagrams showing 
 your pump model in action. 
 
 Project n. How MUCH WATER is WASTED BY DRIPPING FAUCETS? 
 
 Devise a method to find out how much water is lost from a leaky 
 faucet. How much could be lost in a year? 
 
 If the water is metered, what is its cost? 
 
 What would be the difference in gallons lost or in money value 
 per year in the following instances? 
 
 1. When the leak is drop by drop. 
 
 2. When the smallest possible stream is running. 
 
 74 
 
PURE WATER 
 
 75 
 
 Let your report include all details of your processes, and also a 
 report on the results of any attempts to stop the loss. 
 
 What if similar leaks occurred in half the faucets in town? 
 
 Pure water. What is pure water ? We have already 
 seen water condensed as a product of a burning candle, 
 and in a future chapter we shall see that it is the product 
 of burning hydrogen in oxygen. It is, then, a compound 
 produced by the combination of the chemical elements, oxy- 
 gen and hydrogen. All pure water contains hydrogen and 
 oxygen and nothing else. When other substances are mixed 
 with water there are certain methods by which pure water 
 may be separated from some or all of the impurities. One 
 purifying process is distillation. Let us see if this gives 
 us pure water from impure water. 
 
 Experiment. To find a method of purifying water. 
 
 Materials: Two 500 cc. flasks. A one-hole rubber stopper. Glass tube. 
 
 Ring stand. 
 Method: Prepare a sample of impure water by adding a teaspoonful of 
 
 salt and an equal amount of clay or fine sand, and a few crystals of 
 
 potassium permanganate to a half pint 
 
 of water. Fill one flask about half 
 
 full of the prepared water and place 
 
 on ring stand. Arrange to carry the 
 
 steam through a bent glass tube into 
 
 the other flask which stands under a 
 
 stream of cold water. Heat the flask 
 
 which is supported on a ring stand. 
 
 When an inch depth of distilled water 
 
 has been prepared remove the heat. 
 Results and Conclusion: How does the 
 
 distilled water compare with the 
 
 original in appearance? In taste? 
 
 What can you say regarding distillation as a method for purifying 
 
 water? Are any of the impurities left in it? Explain fully the pro- 
 cess of distillation. . 
 
 Distillation apparatus. 
 
7 6 
 
 WATER IN THE HOME 
 
 Rain water. When we think it out rain water must 
 also be very pure, for is it not condensed in somewhat the 
 same way as the drops of water we collected in the last- 
 experiment? Breathe on a cool glass. What happens? 
 The little drops of moisture have been condensed because 
 warm, moist air was suddenly cooled. Moisture in the 
 air comes from evaporation from water surfaces and from 
 all moist surfaces. Leaves give off moisture in the form of 
 
 water vapor. An acre of 
 clover may give off from 
 500 to 750 tons of water 
 during a single season. 
 The production of one 
 pound of some plant 
 foods requires that two 
 to five tons of water be 
 taken from the soil and 
 most of this is evapo- 
 rated into the air from 
 the leaves. An acre of 
 Indian corn gives off 
 nearly a thousand tons of water in a season. When this 
 moisture in the air condenses clouds form. From clouds 
 water falls in the form of rain. 
 
 How we get rain water. In many parts of the world 
 people drink rain water. On the islands of Bermuda, for 
 example, great cisterns are cut in solid rock to hold the 
 water, and the people of the islands depend entirely upon this 
 supply. If rain water is collected in clean cisterns or bar- 
 rels it is perfectly pure. But unfortunately the cisterns 
 and rain barrels are sometimes not clean. Roof drains and 
 gutters are allowed to become clogged with decaying vege- 
 
 Explain this diagram. 
 
SPRINGS AND WELLS 
 
 77 
 
 table matter or sometimes a poor quality of paint used on 
 the roofs will come off in the water. All of these things 
 
 Diagram to show the relation of springs and wells to underground water. 
 
 cause rain water to become unfit for drinking purposes. 
 An excellent plan is to have the first water which falls run 
 off without entering the barrel or cistern, because that 
 water is almost sure to contain dust and other impurities. 
 The best type of cistern is a tank of non-porous material 
 placed in the ground. 
 
 Springs and wells. Any boy or girl who has lived in 
 the country knows what a spring is and any one with a 
 little thought can see how a spring might arise from rain 
 water. The rain soaks into the ground until it comes to 
 a layer through which it cannot pass (impervious layer). 
 It then seeps along until it acquires pressure enough to 
 flow out. If the saturated zone rises to the surface a 
 spring may result. A glance at the accompanying diagram 
 will show how springs occur. In a gushing spring the water 
 is forced out under pressure. Water which has soaked into 
 the ground at some point far distant, often travels under- 
 ground between two layers of impervious material, follow- 
 ing along some layer of soil or rock which allows its passage, 
 and finally finds its way to the surface through some crack 
 or hole in the hard rock. Artesian wells are made when 
 
WATER IN THE HOME 
 
 such underground water sources have been tapped artifi- 
 cially. Sometimes this water may run underground for a 
 long distance, and come from a much higher altitude, so 
 that when it is tapped it shoots into the air to some height. 
 What is impure water? We usually consider water 
 pure unless it contains something that is injurious to health. 
 Ordinary dirt or mud found in water will not cause illness 
 unless there is decaying organic matter in it. Wherever 
 we find decay, we find germs which cause this decay, so 
 impure water, from a health standpoint, is water containing 
 germs. When we realize that germs of different kinds 
 exist in the food tube of our body, and that the wastes 
 which are passed off are full of germs, then it is evident 
 that water which contains sewage is impure. Any water 
 
 drawn from the sur- 
 face of the land 
 would be more likely 
 to contain such 
 wastes, and hence 
 would be more dan- 
 gerous than water 
 coming from under- 
 ground. 
 
 Safe wells and 
 deadly ones. - 
 Many of us who 
 have visited the 
 country on our vaca- 
 tions remember with pleasure the cold water from the deep 
 well or hillside springs near the farm house. Look at the 
 picture and see how a spring may be polluted by a cess- 
 pool. We have all doubtless seen places where the well 
 
 A spring located like this one is deadly. Are there 
 any such in your locality? 
 
HOW WE GET WATER INTO OUR HOUSES 
 
 79 
 
 water might be a source of danger, for all the wastes from 
 the house sinks, from the barnyard, and from the privy 
 or cesspool might soak into the well and render it im- 
 pure. Could you really determine a safe place for a well 
 without knowing 
 something of the 
 rock and soil under 
 the house and 
 grounds? Drainage 
 from the soil may 
 mean that impuri- 
 ties reach the well. 
 We must also pro- 
 tect the well from 
 the surface drainage. 
 Study the picture 
 of the two wells 
 shown here, and explain why the building of a con- 
 crete parapet which slopes away from the opening of the 
 well will protect the water in the well. In addition to 
 surface protection, we should know how the land drains 
 so as to be sure that the well is safe. If one is uncertain 
 as to the purity of the water, a sample can be sent to the 
 town or state bacteriologist, to determine whether the 
 water is safe to drink. This should be done in any case 
 where you suspect that the water is not pure. A driven 
 well on a slight elevation, when the pipe is driven deep into 
 the soil and situated at least 100 feet from a cesspool, or 
 barnyard, will in ordinary sandy soil give pure water. 
 This makes a particularly safe well. 
 
 How we get water into our houses. This is a problem 
 that the city dweller does not think much about, because 
 
 Would you choose your water supply from A or from B ? 
 
8o 
 
 WATER IN THE HOME 
 
 water is delivered directly to his home through pipes. The 
 problem of city water supply will be taken up later. It is 
 sometimes quite easy for the country house to have running 
 water simply because water is pulled down by gravity, or 
 " runs down hill." If the spring or source from which the 
 water is taken is above the height of the house, it can be 
 piped into the house easily ; if the well or spring is below 
 the house we have a different problem. 
 
 If the country boy or girl acquires a little knowledge of 
 air pressure, it might enable him or her to plan how to 
 
 make use of this knowledge to 
 deliver water into the house. 
 We have already seen that air 
 has weight. If you take a 
 tumbler of water, place a 
 smooth card over the tumbler 
 and then invert it carefully, 
 you can lift the glass upside 
 down with the water in it. 
 A moment's thought will tell 
 you that something is pressing 
 upward on the card, or that 
 the air pressing against the 
 card weighs more than the 
 water held in the glass. If you take a wide-mouthed bottle, 
 fill it with water, insert a cork containing a glass tube, and 
 then try to suck the water out you will be unable to do so. 
 Loosen the cork a little and then try, and you will find that 
 you can suck the water out. We may demonstrate this 
 same principle in another way. 
 
 Experiment. To show how air pressure can lift water. 
 
 Materials: A U-tube, piston, and stopper to fit, a glass tube. 
 
 The water is held in the glass by the 
 upward pressure of the air. 
 
HOW WE GET WATER INTO OUR HOUSES 81 
 
 Method and Results: (a) Fill the U-tube with water. Push the piston 
 three fourths of the way down one side of the U-tube. Place the 
 stopper in the other end, making sure that it is air-tight. Pull the 
 piston to the top of 
 the tube. Result? 
 (b) Repeat (a) and 
 leave the end of the 
 tube open. Result? 
 
 Conclusion : Explain 
 why the water fol- 
 lows the piston to a 
 higher level in one 
 case than in the 
 other. 
 
 Application: If the 
 tube were straight and dipped into a jar of water, would the water 
 follow the piston? Explain. Explain how one can drink soda water 
 through a straw. 
 
 Let us apply this principle to the pump. If the tube 
 is placed in the water as in the diagram and we suck on 
 
 the tube, we can pull 
 the water up. This 
 is because we have 
 removed the pres- 
 sure of the air in 
 the tube and this al- 
 lows the air outside 
 the tube to force the 
 water up the tube. 
 If we now substi- 
 tute for the tube the 
 The lift pump. pump, consisting of 
 
 a piston (see diagram) containing a lifting valve, we see 
 that when this piston is raised the water is pushed into the 
 tube by the weight of the air pressing down on the water 
 
 H.-WHIT. CIV. SCI. IN THE HOME 6 
 
82 
 
 WATER IN THE HOME 
 
 in the cistern. When the piston is lowered the valve in 
 the piston opens, thus allowing the water to run into the 
 space above the piston. On the next upward stroke of 
 the piston this water which is held above is lifted still 
 higher in the tube until eventually 
 it flows out of the pump. This 
 pump, known as the lift pump, will 
 only raise water to a height of 
 about 33 feet because the weight 
 of the air, which presses down with 
 a force of fifteen pounds to the 
 square inch upon the surface of the 
 water in the cistern, can balance a 
 column of water only 33 feet high. 
 In practice the lift pump will rarely 
 lift water more than 28 feet because 
 of leakage around the piston and 
 valves. 
 
 If we wish to force water above 
 twenty-eight feet we use a force 
 pump. This is illustrated in the 
 accompanying diagram. Study it 
 carefully and explain why we are 
 able to raise water higher by this method than by the lift 
 pump. Chamber A holds air which may be compressed 
 in order to give a continuous flow of water. Can you ex- 
 plain how it does this? 
 
 The pneumatic tank system. In some houses a supply 
 system by which water can be piped and sent to all parts 
 of the house is used. This can be done through the use of 
 a pneumatic tank. (See illustration on page 83.) Water is 
 forced into the tank and the confined air above it is com- 
 
 The force pump. 
 
THE PNEUMATIC TANK SYSTEM 83 
 
 pressed so that it exerts great lifting power. Thus when 
 the tank is three fourths full of water the air is compressed 
 to one fourth of its original volume and the pressure 
 becomes four times that of the atmosphere, or four atmos- 
 
 Pneumatic tank system of distribution of water. 
 
 pheres. Such a pressure will easily force water higher than 
 the top of an ordinary house. 
 
 Experiment. To demonstrate the use of the pneumatic tank. 
 
 Materials: An eight-ounce, wide-mouth bottle. Two-hole rubber stop- 
 per. Glass tubes. Force pump. Ring stand. Rubber tubing. 
 
 Method: Invert the bottle and support it on the ring stand. Make a U 
 bend at one end of a four-foot glass tubing. Insert this in the rubber 
 
8 4 
 
 WATER IN THE HOME 
 
 stopper. One end of the 
 other glass tube is con- 
 nected by a rubber tub- 
 ing to the outlet valve of 
 the force pump. The in- 
 let valve of the pump is 
 connected by a rubber 
 tubing to a jar of water. 
 Wire the stopper securely 
 in the mouth of the bottle. 
 Pump water into the bot- 
 tle, and as it presses the 
 air, note how high it rises 
 in the glass tube. Connect 
 another four-foot length of 
 glass tubing on top of the 
 first one. When the water 
 fills one fourth of the bot- 
 tle, what is the height of 
 the water in the tube ? 
 
 Application: Apply this 
 principle to a house sup- 
 ply. How high could the 
 water be raised if the 
 air in the bottle were compressed to half its original volume ? 
 
 Faucets. Any water system in the house means that 
 we must have 
 pipes that carry 
 the supply from 
 where the water 
 enters the house 
 to the kitchen, 
 to the laundry 
 tubs, to 
 bathroom 
 
 the 
 and 
 
 toilets. A cut-off 
 valve is placed 
 
 Two types of faucets: screw and spring. 
 
HOW TO STOP FAUCETS FROM DRIPPING 
 
 close to the point where the water enters the house. 
 Why ? In order to obtain water when we wish it a device 
 called the faucet is necessary. A careful study of the two 
 diagrams will shw how these devices are operated. The 
 type most in use is known as the screw faucet. In this 
 type, as the handle is screwed down, a washer, which may be 
 a round perforated disc of rubber, is forced down over the 
 opening where the water flows, thus making it water-tight. 
 In another common type of faucet, the pressure of a spring 
 (see diagram) holds the" washer down so that no water can 
 
 Water waste per year. 
 
 get out. When we squeeze the handles together, this pres- 
 sure is released and the water flows through. 
 
 How to stop faucets from dripping. Any handy boy, 
 or girl either, for that matter, should know how to stop 
 faucets from dripping. The first thing to do is to turn 
 off the supply of water at the cut-off in the cellar, 
 then with your wrench take off the handle of the faucet 
 and remove the washer. You will probably find the washer 
 either broken or badly worn. A new washer which can be 
 procured at any hardware store should then be inserted and 
 the handle replaced. Sometimes a faucet when turned on 
 gives an annoying noise, due to vibration as the water 
 passes through. If caused by a loose washer it is easily 
 remedied. Leaky faucets waste money ; do not allow 
 any of them in your home. 
 
86 
 
 WATER IN THE HOME 
 
 What we mean by solution. You are all aware of the 
 fact that sugar placed in your lemonade soon dissolves in 
 it and disappears, but you can taste the sugar in all parts 
 of the glass of lemonade. If you were to allow crystals 
 of eosin (the material from which red ink is made) to dis- 
 solve in a bowl of water, in a short time the eosin would 
 have passed to all parts of the water, giving it a uniform 
 pink color. 
 
 When a substance completely dissolves in a liquid so as 
 to become permanently a part of it, we say the substance 
 
 is soluble in water, 
 and that we have 
 a solution. Water 
 takes up mineral 
 matter in solution. 
 Rain water, al- 
 though perfectly 
 
 Formation of caves by water running through lime- pure as it drODS from 
 
 the clouds, after 
 
 soaking into the ground may soon take up into itself mineral 
 matter by solution. Certain minerals, particularly com- 
 pounds of calcium (lime) and magnesium, are slightly soluble 
 in ground water, and indeed in some parts of the country, 
 great gaps and caves have been formed by water gradually 
 running through limestone and dissolving it out. We 
 must not confuse solutions with muddy water, for if we 
 allow a glass of muddy water to stand, the mud eventually 
 settles to the bottom, or if the water is passed through filter 
 paper, it remains on the filter ; but when mineral substances 
 are in solution, they pass through the filter with the water. 
 Hard and soft water. Water that has taken up a con- 
 siderable amount of soluble mineral material is called hard 
 
HOW WE MAY MAKE WATER PURE 
 
 water, while rain water and other waters that have little 
 or no dissolved mineral matter in them are known as 
 soft waters. We can usually tell hard water because soap 
 does not readily make a good lather, or suds, with it. We 
 find that the soap comes to the top in a sticky, insoluble 
 scum. Hard water leaves a deposit in kettles, feels harsh 
 to the hands, and requires much 
 w r ashing powder, else it is very 
 wasteful of soap. Such waters 
 are perfectly good to drink, but 
 must be treated with chemicals 
 before using them for washing 
 purposes. Washing soda added 
 to the water before soap is used 
 will usually make the water bet- 
 ter suited for washing. 
 
 How we may make water 
 pure. We have already seen 
 that harmful water contains 
 germs. Germs are living organ- Notice the bubbles of air which es- 
 
 . , fit cape when water is first heated. 
 
 ISmS, and many Of them do Why is boiling water sometimes 
 
 recommended? . 
 
 harm when they are alive. Any 
 
 method which will kill them and will not harm the water 
 will therefore render it safe to drink. Boiling water for a 
 period of at least ten minutes will kill practically all harmful 
 germs, so that we may- safely drink such water. Unfortu- 
 nately, boiled water has a flat and unpleasant taste, due to the 
 fact that the air which was held in solution has been forced 
 out of it. In order to make such water palatable we may 
 shake it up in a bottle half full of air or allow it to stand 
 exposed to the air. Such water dissolves some of the air 
 and again assumes its palatable taste, and is good to drink. 
 
88 
 
 WATER IN THE HOME 
 
 SCORE CARD. WATER IN MY HOME 
 
 EXCELLENT 
 
 FAIR 
 
 VERY POOR 
 
 MY 
 
 SCORE 
 Total 
 
 A SAFE 
 WATER 
 SUPPLY 
 
 Water protected 
 f r om surface 
 drainage (deep) 
 
 (s) 
 
 Water without sedi- 
 ment (i) 
 Water having no 
 color (i) 
 Water having no 
 odor (indication 
 of organic mat- 
 ter) (2) 
 Use of bottled wa- 
 ter for drinking 
 (i) 
 
 Water from shallow 
 source protected 
 against surface 
 drainage (3) 
 Water having some 
 sediment (5) 
 Water having slight 
 color (|) 
 Water having slight 
 odor (i) 
 
 Boiled water for 
 drinking (i) 
 
 No protection from 
 drainage. Cess- 
 pool or privy 
 within 100 ft. (o) 
 Much sediment (o) 
 
 Much color (o) 
 Much odor (o) 
 
 Neither boiled nor 
 bottled water 
 used for drinking 
 (o) " 
 
 
 
 AMPLE 
 WATER 
 SUPPLY 
 
 Always enough wa- 
 ter for all pur- 
 poses at all sea- 
 sons including 
 possible fire (5) 
 Head of water suf- 
 ficient to throw 
 stream over 
 house (5) 
 
 Supply only to two 
 lower floors of 
 home (3) 
 
 Supply sometimes 
 low in hot sum- 
 mer or cold win- 
 ter (3) 
 
 Supply only to low- 
 est floor of house 
 (2) 
 
 Supply usually low 
 in winter or sum- 
 mer (i) 
 
 
 
 
 
 ALL PARTS 
 SUPPLIED 
 WITH PIP- 
 ING AND 
 FIXTURES 
 
 Water supplied un- 
 der pressure to 
 bathroom (i), 
 toilet (2), sink 
 (i), and tubs 
 in kitchen or 
 laundry (i) 
 No pumps : gravity 
 system: piped to 
 all parts of the 
 house (<;) 
 
 Water supplied un- 
 der pressure from 
 pneumatic tank 
 to bathroom (i), 
 toilet (2), sink 
 (i), tubs (i) 
 
 Pumps: no pneu- 
 matic tank. W r a- 
 ter supplied only 
 to sink (i), tubs 
 (i) 
 
 .... 
 
 .... 
 
 CONDI- 
 TION OF 
 PLUMBING 
 
 Pipes in good con- 
 dition; no leaks 
 (2) 
 Faucets all tight; 
 no dripping (2) 
 Pipes never freeze 
 
 (2) 
 
 Plumbing all ex- 
 posed (2) 
 No odors (2) 
 
 Pipes in fair condi- 
 tion ; sometimes 
 leak (i) 
 Faucets drip at 
 times (i) 
 Pipes freeze in very 
 cold weather (i) 
 
 Plumbing partly ex- 
 posed (i) 
 Slight odor at times 
 (i) 
 
 Pipes old and leaky 
 (o) 
 
 Faucets constantly 
 drip (o) 
 Pipes freeze in or- 
 dinary winter 
 weather (o) 
 No exposed plumb- 
 ing (o) 
 Much odor from 
 plumbing (o) 
 
 
 
 SOFT 
 WATER 
 PROVIDED 
 
 Water is soft (4) 
 
 Rain water and ce- 
 ment cistern (3) 
 
 Bucket pump or 
 other means of 
 mixing air with 
 water (2) 
 Flow-off of first 
 rain water from 
 roof (i) 
 
 Water of medium 
 hardness (2) 
 Rain water in tight- 
 ly covered barrel 
 (i) ' 
 Water falls from 
 height into barrel 
 thus mixing air 
 with, it (i) 
 Roof clean, water- 
 proof paint (i) 
 
 Water very hard 
 (o) 
 Rain barrel ex- 
 posed, no tight 
 cover (o) 
 No method of mix- 
 ing air in water 
 (o) 
 
 Water smells or is 
 dirty (o) 
 
 .... 
 
 
 GRAND TOTAL 
 
SCORING MY HOME WATER SUPPLY 89 
 
 Scoring my home water supply. Any boy or girl who 
 has read this chapter with thought now realizes the impor- 
 tance of our water supply and how great an advantage 
 those of us who live in cities have over those who have 
 no safe supply or to whom it is not delivered in pipes. 
 The score on the preceding page will probably be much 
 higher for those who live in the city. 
 
 REFERENCE BOOKS 
 
 Barber, General Science, Chapter IX. Henry Holt and Company. 
 
 Broadhurst, Home and Community Hygiene, Chapter V. J. B. Lippincott Company. 
 
 Butler, Household Physics. Whitcomb and Barrows. 
 
 Caldwell and Eikenberry, General Science, Chapter IX. Ginn and Company. 
 
 Clark, Introduction to Science, Chapter XXXIV. American Book Company. 
 
 Hazen, Clean Water and How to Get It (Teacher's use). John Wiley and Sons. 
 
 Hoadley, Essentials of Physics. American Book Company. 
 
 Hunter, A Civic Biology, Chapter VI. American Book Company. 
 
 Lynde, Physics of the Household. The Macmillan Company. 
 
 Ritchie, Primer of Sanitation, Chapter XX. World Book Company. 
 
 Smith and Jewett, Introduction to the Study of Science, Chapter V. The Macmillan 
 
 Company. 
 
 Yearbook, U. S. Dept. Agri., Clean Water and How to Get It on the Farm. 
 Weed, Chemistry in the Home, Chapter III. The American Book Company. 
 
CHAPTER VI 
 THE USES OF FOODS 
 
 Problems. i. To learn the uses of foods. 
 
 2. To learn of what our bodies are made and what must 
 be supplied if we are to grow. 
 
 3. To learn to tell what different nutrients foods contain. 
 
 4. To learn how and where food is made ready for ab- 
 sorption. 
 
 5. To determine reasons for differences in diets. 
 
 6. How to select a proper and economical variety of food. 
 
 7. How and why foods should be cooked. 
 
 Experiments. i. To show the presence of carbon and water in foods. 
 
 2. To make tests for the carbohydrate foods, sugar and starch. 
 
 3. A test for protein. 
 
 4. A test for fat or oil. 
 
 5. To show digestion of starch with saliva. 
 
 Project I. WHAT NUTRIENTS ARE IN THE FOODS COMMONLY 
 
 USED IN MY HOME? 
 
 1. Make a list of the common foods used. 
 
 2. Test some of these for starch, sugar, fat, and protein. 
 
 3. Consult food tables in books to learn the proportions of the 
 different nutrients and their fuel value in foods. 
 
 Project n. To OBTAIN STARCH FROM POTATOES. 
 i . Look up a method or device by which you can separate starch 
 granules from potatoes. 
 
 90 
 
COMPARISON OF THE BODY WITH AN ENGINE 91 
 
 2. Prepare an exhibit to show what you have done. You might 
 show: 
 
 (1) Potatoes equal in weight to those used. 
 
 (2) The starch you obtained. 
 
 (3) The residue. 
 
 (4) A chart comparing your results with the actual amount 
 of starch in potatoes as learned from food tables. 
 
 (5) A written report of your work and results including an 
 account of starch factories, possibly illustrated with pictures. 
 
 Project III. To PLAN FOR ECONOMICAL BUYING FOR OUR FAMILY 
 
 FOR ONE WEEK. 
 
 1. Determine foods and amounts of each. 
 
 2. Determine proportion of different nutrients needed. 
 
 3. Compare costs. 
 
 4. Purchase cheaper foods giving required nutrients. 
 
 5. Make a written report comparing your purchases with those 
 of the previous week. Give your conclusions before the class. 
 
 Comparison of the human body with an engine. We 
 have already compared the human body to an engine. Let 
 us go farther with this comparison. It is like an engine in 
 that it contains very many complex parts, each of which 
 has some particular work to do ; for example, the fire box, 
 or steam chest of the engine, or the carburetor of a gaso- 
 line engine, or in the case of the human body, there are 
 the lungs and passages leading to them, the food tube 
 with its different complex parts, and the system of blood 
 tubes and the blood within. We find, moreover, that an 
 engine and the human body both work more or less auto- 
 matically, although the locomotive is controlled from the 
 outside, while in the body control comes from within. 
 Both engine and body need fuel in order to do work. In 
 order to release the energy locked up in the fuel, we must 
 have oxygen to unite with it. Both engine and body must 
 
92 THE USES OF FOODS 
 
 get rid of the waste material, for no engine can run with 
 its fire box clogged with ashes, nor can any human being 
 live long without getting rid of wastes. Neither engine nor 
 body can be overworked without breaking down. Rest 
 has been found to be necessary for metals as well as for 
 man. It is necessary to allow the most smooth-running 
 
 Fuel gives heat and energy, and makes motion possible. (After Hoadley.) 
 
 machine to take a rest now and then if the machinery is 
 to be kept in good condition. 
 
 But the human machine differs from the engine in some 
 respects. It has the remarkable ability to build itself out 
 of the very materials that are put into it as fuel. No 
 engine could do this. Besides, as we have already seen, 
 germs may attack the human body and render it unable to 
 carry on its regular work. Owing to the activity of these 
 germs, we become ill. 
 
 What the body is made of. If we study the figure on the 
 next page, we find that the human body is made up of 
 about 72 % oxygen, 13.5 % carbon, 9 % hydrogen, 2.5 % 
 nitrogen, about 3 % of various mineral salts, including cal- 
 cium, phosphorus, potassium, sulphur, sodium, chlorine, 
 magnesium, iron, and some others. All of these substances 
 
WHAT THE BODY IS MADE OF 
 
 93 
 
 mentioned are known as chemical elements. The first four 
 named, oxygen, carbon, hydrogen, and nitrogen, are the ones 
 which are of most interest to us just now, as they form the 
 bulk of most foods. Carbon, oxygen, hydrogen, and nitrogen, 
 for example, come to us in such 
 foods as meats and vegetables. 
 Water supplies much of the hy- 
 drogen and oxygen. One ex- 
 periment which can easily be 
 performed at home will show 
 some of the elements contained 
 in foods. 
 
 Experiment. To show presence of car- 
 bon and water in foods. 
 
 Materials: Several foods, as potatoes, 
 meats, oatmeal. A metal plate or 
 small piece of sheet metal. Burner. 
 Glass funnel. Sugar. Sulphuric 
 acid. A 500 cc. beaker. 
 
 Method and Results: Place a small 
 piece of the food to be tested upon 
 the metal and heat it. Hold the 
 glass funnel over it as a test for 
 escaping moisture. Continue heat- 
 ing until a black residue is left. 
 What in all probability is this black 
 substance ? 
 
 Strong sulphuric acid has such attraction for water that it will withdraw 
 the water from many plant products and generate enough heat to sepa- 
 rate it from the black carbon. This is very strikingly done with sugar. 
 Mix 60 grams of sugar in 45 cc. of water in a 5oo-cc. beaker which is 
 set on a plate. Pour 60 cc. concentrated sulphuric acid into the sugar 
 solution. Result ? (If performed as an individual pupil experiment use 
 one fourth quantities suggested.) Can you name the black product? 
 
 Some of these chemical elements, although present in 
 very small quantities, have extremely important uses ; 
 
 Chart to show the percentage of 
 chemical elements in the human 
 body. 
 
94 THE USES OF FOODS 
 
 for example, it has recently been discovered that the 
 beating of the heart, the contraction of working muscles, 
 and the ability of our nerves to send messages depend upon 
 the presence of very minute quantities of calcium, magne- 
 sium, potassium, and phosphorus in the body. 
 
 Two uses of foods. Scientists have shown us that our 
 common foods are made up of substances called nutrients. 
 These nutrients are known as proteins, fats, carbohydrates, 
 mineral matter, and water. Three of these nutrients, 
 protein, fat, and carbohydrate, are consumed in the body 
 to release energy. The mineral matter serves to aid in the 
 making of bone, in carrying on digestion, and in other body 
 functions, while the water is largely used as a vehicle to 
 carry the nutrients, and forms a very large percentage of 
 the human body. Protein, of which eggs, lean meat, and 
 the germ or gluten of wheat are examples, is used for mak- 
 ing body material. The following table taken from a 
 government bulletin l sums up the uses of the nutrients to 
 man. 
 
 THE FUNCTION OF THE NUTRIENTS IN THE BODY 
 
 Protein Forms tissue (muscles, 
 
 White of eggs (albumen), tendon, and probably 
 curd of milk (casein), fat), 
 lean meat, gluten of 
 wheat, etc. 
 
 Fats Form fatty tissue. 
 
 Fat of meat, butter, olive 
 
 All serve as fuel and 
 yield energy in form 
 of heat and muscular 
 strength. 
 
 oil, oils of corn and 
 wheat, etc. 
 
 Carbohydrates Transformed into fat. 
 
 Sugar, starch, etc. 
 Mineral matter (ash) . . Aid in forming bone, as- 
 Phosphates of lime, pot- sist in digestion, in ab- 
 ash, soda, etc. sorption and in other 
 ways help the body 
 parts do their work. 
 
 Water is used as a vehicle to carry nutrients, and enters into the composition of liv- 
 ing matter. 
 
 1 Adapted from Atwater, Principles of Nutrition and Nutritive Value of 
 Food, U. S. Department of Agriculture, 1902. 
 
HOW TO TEST FOR NUTRIENTS IN FOODS 
 
 95 
 
 Where the nutrients are found. Carbohydrates form 
 the chief nutrient in the foods we call cereals, breads, 
 cake, fleshy fruits, sugars, jellies, and the like. Fats and 
 oils are found in nuts and some grains, and make up the 
 greater part of bacon, pork, lard, and butter. Animal 
 foods yield our chief supply of protein. White of egg and 
 lean meat are almost pure protein and water. Proteins 
 are most abundant in those plants which are richly sup- 
 plied with nitrogen such as peas and beans, grains and nuts. 
 
 Foods rich in protein. (After Tolman.) 
 
 How to test for the nutrients contained in foods. 
 
 Since it is necessary for us to have some or all of these 
 various nutrients in our daily diet, it will be interesting 
 for us to learn how to determine their presence in foods. 
 An interesting home experiment is the testing of as many of 
 the foods which make up your daily dietary as you can. 
 
 Experiment. Tests for the carbohydrates, sugar and starch. 
 
 Materials: Starch. Grape sugar. Iodine solution. Fehling's solution. 
 
 Test tubes. Various foods to be tested. Bunsen burner. 
 Test for Starch: Mix a little starch with cold water and heat to boiling 
 in a test tube. Add a few drops of iodine solution. The resulting 
 blue or blue-black is the characteristic test for starch. The test may 
 
96 THE USES OF FOODS 
 
 be made on cold starch, but is quicker and surer if the substance tested 
 has been heated to the boiling point. The heat causes the granules 
 to swell and burst the cell walls which inclosed them. 
 
 Test for Grape Sugar: Place a little grape sugar in a test tube one fourth 
 full of water. Add an equal amount of Fehling's solution. Heat to 
 the boiling point. The characteristic brick red color which appears 
 is the test for grape sugar. Cane sugar heated or digested with diluted 
 acid changes in part to grape sugar, but pure cane sugar will give no 
 result with this test. 
 
 Test many foods, as oatmeal, bread, potatoes, rice, sirup, molasses, 
 cabbage, apples, bananas, candy, cheese, meat, etc., for starch and 
 sugar. List the foods under the following headings : 
 
 MUCH STARCH 
 
 LITTLE STARCH 
 
 No STARCH 
 
 GRAPE SUGAR 
 
 
 
 
 
 Experiment. To test for fats or oils. 
 
 Materials : Pork or butter, oily nut, corn meal, paper. 
 
 Method and Results : Rub a piece of pork or butter on a piece of paper. 
 Lay a crushed nut or a little corn meal on a piece of paper and place 
 it in a warm oven for a few minutes. The oil or fat absorbed by the 
 paper makes a semi-transparent spot which is seen when held toward 
 the light. 
 
 Application: Test various foods. Those which give a test without 
 warming in the oven have a higher per cent of fat. 
 
 Experiment. To test for protein. 
 
 Materials: White of egg (a typical protein). Test tube. Concentrated 
 nitric acid. Ammonia. 
 
 Method and Results: Pour the white of egg into boiling water to coagu- 
 late it. Pour off the water and add a few drops of strong nitric acid 
 to the solid white of egg. Is there any change? Rinse the acid off 
 with water and add ammonia. The lemon color after the addition of 
 the acid and the deep orange following the addition of the ammonia 
 complete the test for protein. Heat quickens the reaction. 
 
 Application of Test: Try this test on such foods as lean meat, bread, 
 cheese, beans, and rice. Which ones show the presence of protein? 
 
THE FOOD REQUIREMENTS OF THE BODY 97 
 
 COMPOSITION OF FOOD MATERIALS. 
 
 EEED cm em ^ /-.? 
 
 COMPOSITION OF FOOD MATERIALS. 
 
 WHITE BREAD WHOLE WHEAT BREA 
 
 Water 35. i Wttr J 
 
 Sa5LP'Otem-9Z Prote.n 9 7 
 
 09 
 
 COMPOSITION OF FOOD** MATERIALS. 
 
 COMPOSITION OF FOOD MATERIALS. 
 
 SUGAR 
 
 Foods of plant origin. Select 5 foods containing a high percentage of protein, 5 with a 
 high percentage of carbohydrates, 5 with a high percentage of water. Do vegetable 
 foods contain much fat ? Which of the above-mentioned foods have the highest 
 burning value ? 
 
 H.-WHIT. CIV. SCI. IN THE HOME 7 
 
9 8 
 
 THE USES OF FOODS 
 
 COMPOSITION OF FOOD MATERIALS. 
 
 B mm f~i wm BB.^-" 
 
 "cop r " c 
 
 SALT COD 
 
 LI .( [ipeimM SUIHMS C.F. UllGWORW 
 
 COMPOSITION OF FOOtTMATERIALS. 
 
 BBi ClMl 
 
 M05 uiMin .1. PWW 
 
 tiKrlClta> 9 tal>l 
 
 COMPOSITION OF FOOD MATERIALS. 
 
 BB i:::: :: i r~ I F;r^] g^g i 
 
 COMPOSITION OF FOOD' MATERIALS' 
 
 1 Bffltllliil | : | WMWA fES^^ F u l 
 
 CREAM CHEESE COTTAGE CHEESE 
 
 "*'"' '* '%==*-ssi 
 
 P-o.;n:259 W "r 720 
 
 h,dtt 2 4 
 
 Foods largely of animal origin. Compare with the previous chart with reference to 
 amount of protein, carbohydrate, and fat in foods. Compare the burning value of 
 plant and animal foods. Compare the relative percentage of water in both kinds 
 of foods. 
 
HOW FOODS ARE PREPARED FOR USE IN BODY 99 
 
 The food requirements of the body. For some time 
 chemists have had a standard of measurement for heat 
 given off when substances are burned. This heat unit 
 is called a calorie. A calorie is the amount of heat 
 required to raise the temperature of one pound of water 
 from zero to four degrees, Fahrenheit. The burning value 
 of foods may be determined and measured in calories. 
 Professor Atwater and others, by means of a series of in- 
 teresting experiments, endeavored to show how much 
 fuel is needed by our bodies each day, as well as the amount 
 of building material. It has been found, for instance, 
 that the human body needs from three to a little over five 
 ounces of protein each day, and enough fuel food to furnish 
 the body with from two thousand to six thousand calories. 
 We may adopt as our standard proportion of nutrients 
 i (protein): i (fat): 4 (carbohydrate). Stated in another 
 way this is about a quarter of a pound of protein, a quarter 
 of a pound of fats, and a pound of carbohydrates each 
 day for a person doing moderate work. More food would 
 be needed if hard work had to be done. 
 
 How foods are prepared for use in the body. We all use 
 foods, but the body does not use them in the condition in 
 which we buy them . If we think for a moment, we will remem- 
 ber that food, in order to become a part of the body, has to 
 pass through the wall of the food tube and get into the blood, 
 and from there be carried to the place where it is to be used. 
 You cannot pass a solid material through a thick wall. Ob- 
 viously, the food tube has in some way to change the materi- 
 als from solids into liquids so that they can get through this 
 thick wall. This process of changing foods into a liquid con- 
 dition which enables them to pass through the walls of the 
 food tube and become part of the blood is called digestion. 
 
IOO 
 
 THE USES OF FOODS 
 
 Where digestion takes place. If we study the accom- 
 panying diagram of the digestive tract we notice that there 
 are several parts to it : the mouth, with the tongue, teeth, 
 and three pairs of salivary glands, which produce saliva 
 
 in the mouth. Beyond 
 the mouth a smooth 
 muscular tube, known 
 as the gullet, which 
 leads to a bag-like or- 
 . gan, called the stomach. 
 Some people think the 
 stomach is the organ of 
 digestion, but it does 
 only a part of the work 
 of digestion. The stom- 
 ach opens into the small 
 intestine, which in the 
 adult is a much coiled 
 tube about thirty feet 
 in length. In this tube 
 most of the digestion 
 takes place. Into this 
 part of the tube are 
 poured juices from two 
 large glands, the pan- 
 creas and the liver. 
 The wall of the small 
 intestine is thrown into thousands of little projections, called 
 wlli, through which the digested food is absorbed into the 
 blood. The large intestine is the last part of the food tube. 
 Near the junction of the small and the large intestine is a 
 little sac, the vermiform appendix, about which most of you 
 
 Ircxrg' 
 
 Intestine 
 
 3vccll . 
 Intestine 
 
 Apper\<a.i>c 
 
 T^eotucrp^/ 
 
 Digestive tract. 
 
HOW DIGESTION TAKES PLACE 
 
 ici 
 
 know. This is an organ of much harm and little use, because 
 of the disease appendicitis which results from its inflam- 
 mation. 
 
 How digestion takes place. It is not so easy for us to 
 understand how solid foods are made liquid in the food 
 tube, but perhaps the following experiments will help. 
 If we take unsweetened cracker and chew it for some time, 
 we notice it begins to taste sweet. A cracker is composed 
 largely of starch. 
 Mix some powdered 
 cracker, or starch, 
 with a small quantity 
 of water. Pour this 
 mixture into a fun- 
 nel lined with filter 
 paper, and allow the 
 substances to trickle 
 through into a test 
 tube. Take grape 
 sugar of equal weight 
 with the starch. Mix 
 with as much water as before and filter in like manner. 
 We can prove that no starch comes through the filter. If 
 we test the water that drips through with iodine, it does 
 not turn dark blue. If we taste the water which has 
 dropped through from the funnel containing the sugar, 
 we find it is sweet. Evidently sugar passes through 
 this wall, while starch does not. An experiment per- 
 formed with unsweetened crackers shows that mixing a 
 cracker thoroughly with saliva causes some of the starch 
 to change to grape sugar (a kind of digested starch) while 
 cracker moistened with water will not be changed. This 
 
 What does this experiment prove ? 
 
1C? 
 
 THE USES OF FOODS 
 
 change, or digestion, is caused by the presence in the saliva 
 of a digestive ferment called an enzyme. 
 
 Experiment. To show digestion of starch with saliva. 
 
 Add a few drops of sodium carbonate solution to a test tube a third full 
 of starch paste. Add a tablespoonful of filtered saliva warmed to 
 99 degrees F. Keep it at this temperature on the water bath. At 
 the end of ten minutes test a portion of the solution with Fehl- 
 ing's solution to see if any of the starch has been changed to sugar. 
 Result? 
 
 Enzymes and what they do. We shall find in our later 
 study that enzymes perform an important work in the body 
 of plants and animals. They are the active parts of the 
 digestive fluids and cause the digestion of the nutrients 
 
 in different parts of the food 
 tube. Starches are digested 
 in part by enzymes supplied 
 in the mouth, and in part by 
 other enzymes in the small in- 
 testine. Proteins are digested 
 by enzymes in the stomach 
 and intestines. In the small 
 intestine fats are changed 
 in part by enzyme action 
 into a kind of soft soap, 
 in which form they enter the 
 blood. 
 
 The uses of the teeth. If 
 you study the accompanying 
 diagram of the teeth, or better, your own mouth before a 
 mirror, you will notice that some teeth are broad and 
 rather irregular on the upper surface, and are evidently 
 used for grinding. Others are sharp or pointed, and are 
 
 I. Teeth of the upper jaw, from below. 
 7, 2, incisors; 3, canine; 4, 5, pre- 
 molars; 6, 7, 8, molars. II. Section 
 of a tooth. , enamel; D, dentine; 
 C, cement ; P, pulp cavity into which 
 blood vessels and nerves pass to keep 
 the tooth alive. 
 
MOVEMENT OF THE FOOD TUBE 103 
 
 used for cutting or tearing. The long tooth of a dog is an 
 excellent example of a tooth fitted for tearing purposes. 
 Using the diagram, divide the teeth according to their 
 uses, and name them from the chart, as - molars, pre- 
 molars, canines, and incisors. The teeth, with the assist- 
 ance of the tongue, prepare the food for digestion by 
 cutting and crushing it, so that when the tongue pushes 
 it into the gullet, it will be in better condition for digestion. 
 The smaller the particles of food the more surface the en- 
 zymes have to act upon, and consequently the more rapidly 
 digestion takes place in the body. There is, then, a real 
 scientific reason for chewing the food. 
 
 Movement of the food tube as an aid to digestion. 
 Perhaps you have had the experience of losing something 
 held in the mouth by having it slip down the food tube 
 without your being able to get it back again. As this 
 mysterious movement of food through the tube takes place 
 just as well when we are lying down as when we are standing 
 up, it is evidently not due to the force of gravity. The walls 
 of the gullet, the stomach and small intestines are muscular, 
 and are constantly in motion. The stomach itself aids more 
 than the teeth in 
 making the particles 
 of food smaller, for 
 
 the food after it is i ,. . 
 
 swallowed is turned 
 
 Peristaltic waves. 
 
 over and over again 
 
 by the action of this muscular organ, and only very small 
 particles are allowed to go into the small intestine. The 
 large intestine sends along the food by means of wavelike 
 movements. This movement, called peristalsis, occurs in 
 both small and large intestines and is of great importance 
 
104 THE USES OF FOODS 
 
 in passing foods through the food tube and in expelling 
 wastes from it. 
 
 The influence of the mind on digestion. Not many 
 years ago, it was discovered in experiments with the X-ray 
 machine that the peristaltic movements of the food tube 
 were stopped or arrested when a cat or a dog was frightened 
 or angry, but when contented and happy the movements 
 began again and continued normally. These experiments 
 teach us a very real lesson, for our own food tube acts in 
 the same manner. Form the habit of contentment. At 
 meal times especially learn to be cheerful and happy. 
 Laugh and grow fat is a statement founded on simple 
 scientific fact. 
 
 Some reasons for differences in diets. It goes with- 
 out saying that you would not fill up the fire box of 
 your furnace with as much coal on a day that promised to 
 be warm as on a cold day. Similarly we do not always 
 need the same amount and kind of food. A man doing hard 
 work, for example, would need very much more energy- 
 giving food than a man doing little work. 
 
 We find that environment plays a very important part in 
 diet. People living in hot climates need different foods from 
 those in cold climates. The inhabitants of cold countries 
 need more heat-releasing foods, and use fats for this pur- 
 pose. In summer we do not require so much fat as we do 
 in winter, and watery foods, such as fruits, vegetables, 
 milk, eggs, and cereals, are better than much meat and 
 fats. Age should cause a difference in the kind of food. 
 We take food in order to make new body material, to repair 
 what is wasted, and to give us energy. Very young chil- 
 dren grow rapidly, and should use milk largely in their diet. 
 A study of the diagram will show you the reason for this. 
 
FOOD ECONOMY 
 
 105 
 
 Milk contains all the food nutrients, and in about the 
 right proportion for a child. Rapidly growing boys and 
 girls require more food, and more protein food than do those 
 who are older. As a rule boys 
 and men need more food than 
 girls and women. 
 
 Each one of us must deter- 
 mine also whether he or she can 
 easily digest certain kinds of 
 foods. Some of us, for example, 
 cannot eat strawberries or to- 
 matoes without suffering from 
 indigestion, while some of us are 
 able to eat these foods, but can- 
 not take others, for " what is one 
 another man's 
 
 globule$ 
 
 IS 
 
 Composition of milk. What per cent 
 is water? 
 
 man s meat 
 poison." 
 
 Food economy. A study of the table on page 106 
 will show us that the same amount of money will buy 
 vastly different amounts of energy and building material 
 in food. The American family, as a rule, does not expend 
 its money wisely in foods. We should eat to live, and not 
 live to eat. We should learn to like and use cheaper 
 foods which have the same nutritive value as do the more 
 expensive ones, and above all we should learn to eat 
 more fruits, more vegetables and cereals, more milk, and 
 less meat, because meat is more expensive, and because 
 there is danger of eating too much protein. We Americans 
 are fond of meats, and eat more than is good for us. As 
 a result we make some of our organs work overtime and 
 put a strain upon them in order to get rid of the extra 
 protein which forms wastes harmful to the body. 
 
io6 
 
 THE USES OF FOODS 
 
 PROTEIN FATS CARBOHYDRATES FUEL VALUE 
 
 FOOD 
 MATERIALS 
 
 c 
 fl 
 
 H 
 
 s ., 
 
 POUNDS OF NUTRIENTS AND CALORIES OF FUEL 
 VALUE IN 25 CENTS WORTH 
 
 10 
 
 1 LB. 2 LBS. 3 LBS. 
 
 CENTS 
 
 POUNDS! 2.OOO CAL. 4.OOO CAL. 6.OOO CAL. 
 
 Beef .round 
 
 35 
 
 ,,ta POUNPS 
 
 
 
 
 '") CALORIE 
 
 
 
 
 Beef, sirloin 
 
 50 
 
 
 
 
 
 
 
 
 
 Beef, shoulder 
 
 30 
 
 [isr 
 
 
 
 
 
 
 
 
 Mutton, leg 
 
 40 
 
 fe 
 
 (.0 R3=| 
 
 
 
 
 
 
 
 
 Pork, loin 
 Pork, salt, fat 
 Ham, smoked 
 
 30 
 30 
 45 
 
 
 
 
 
 
 
 
 
 
 .56 P 
 
 
 Codfish, fresh, 
 dressed 
 
 25 
 
 
 
 
 
 
 
 
 
 Oysters, 90 cents 
 per quart 
 
 45 
 
 
 
 
 
 
 
 
 
 Milk, 15 cents 
 Per Quart 
 
 Butter 
 
 7K 
 02 
 
 3.33 
 
 .40 
 
 
 
 
 
 tmmm^m 
 
 1 
 
 mmm^m^ 
 
 
 
 
 Cheese 
 
 40 
 
 .63 Pj 
 
 
 
 
 Eggs, 60 cents 
 per dozen 
 
 40 
 
 .63 
 
 1 
 
 
 
 
 1 
 
 
 
 
 Wheat bread 
 
 12^ 
 
 2.00 
 
 WMMMMb 
 
 W 
 
 
 
 
 
 
 Corn Meal 
 
 7 
 
 S.fiO 
 
 &$$$&ffifflfflffiffib 
 
 
 
 %%$( 
 
 Oat Meal 
 
 10 
 
 2.50 
 
 } [ 
 
 
 ' 7 A 
 
 
 Beans, white, dried 
 
 12H 
 
 2.00 
 
 if 
 
 ffifflffifflh 
 
 
 
 Rice 
 
 8 
 
 3.00 
 
 'MW/ 
 
 
 
 
 Potatoes, $1.50 
 
 2M 
 
 10.00 
 
 W^M^^M^/, 
 
 WflMfth 
 
 
 
 Sugar 
 
 10 
 
 2.50 
 
 ^MftMttMsMfflfr, 
 
 Wt^M^MZMb 
 
 WMfa 
 
 
 On the basis of cost and food values shown in the above table, make an economical 
 dietary for one day for a man engaged in light work. Make a second dietary to sat- 
 isfy the same conditions but select expensive foods. Give reasons for the amounts 
 and choice of foods in each case. What is the difference in the cost of these two 
 dietaries ? 
 
VITAMINES AND THEIR USES 107 
 
 Vitamines and their uses. Recent studies have shown 
 that some foods possess peculiar substances known as wtam- 
 ines which are essential to health. For example, one of 
 
 These rats are the same age. They were always fed the same kinds and amounts 
 of food, namely, bread 60%, potatoes 20%, greens 20%, but the one at the left 
 had in addition a tablespoonful of milk daily. (Photo from Battle Creek Sani- 
 tarium.) 
 
 the German raiders was forced to put in at Newport News 
 and have its crew interned because of severe illness among 
 them. They seemingly had all the food necessary, for they 
 had sunk ship after ship and had taken canned goods, 
 wheat flour, and other materials in abundance. The officers 
 had fresh vegetables from time to time while the crew had 
 none, and after a period of nearly three hundred days, a 
 large number of the crew became so ill that medical at- 
 tention was necessary. When these men were given a diet 
 of fresh fruit, milk, eggs, and soups made of boiled skins of 
 vegetables, they were cured in a very short tune. This 
 seems to show that they needed the vitamines which were 
 present in skins of certain vegetables. The chief sources 
 of vitamines for us are the outer coats of rice (unpolished or 
 brown rice), potatoes, carrots, and some other vegetables; 
 eggs, milk, and many fresh fruits, particularly oranges and 
 pineapples. 
 
io8 THE USES OF FOODS 
 
 Marketing. Most mothers and fathers do the market- 
 ing for the family, but it would be good practice for girls 
 and boys to do this for one week. They would find it would 
 not be as easy as it seemed, for one must keep in mind that 
 the cost of foods has little relation to their nutritive value 
 and that some foods that cost a great deal have a low 
 nutritive value. They must also remember that the family 
 has need of fuel for the body and building material as well 
 which must be supplied by foods. If you will study the 
 charts on the preceding pages, you will find that all of these 
 factors must be taken into account in buying for the family. 
 An excellent home project would be for each boy and girl 
 to market for one week, and to bring into class lists with 
 amounts and cost of each article purchased. These should 
 be placed in tabular form, giving the size of the family, 
 approximate age of each member of the family, and all other 
 data which would be necessary in order to discuss the 
 material brought in. Class discussion of these lists would 
 then enable you to decide which one of the marketing 
 lists was the best. Why not try this? 
 
 How to select a proper menu. A practical exer- 
 cise which will enable your teacher and schoolmates to 
 determine whether you have understood the foregoing 
 paragraphs will be to select the proper foods from the 
 three following lists, for breakfast, lunch, and dinner 
 respectively. In preparing these menus, balance the diet, 
 keeping in mind your own occupation, your own age, your 
 own ability to digest foods, and the cost of foods. 
 
 What foods could you substitute for meat to get pro- 
 teins? What articles on the rnenu might you select be- 
 cause of their good taste, but which do not have much food 
 value? Should such articles be part of our diet? Which 
 
WHAT COOKING DOES TO FOODS 
 
 109 
 
 beverages are foods? Which are not? Can you give good 
 reasons for this ? In connection with this menu study the 
 food tables and all diagrams given in the chapter. 
 
 Cantaloupe 
 
 Oranges 
 
 Prunes 
 
 Cornflakes 
 
 Oatmeal 
 
 Shredded Wheat 
 
 Beefsteak 
 Boiled Egg 
 Fried Lamb Chop 
 Fried or Hashed 
 
 Brown Potatoes 
 Hominy 
 
 BREAKFAST 
 
 Griddle Cakes and Apple Sauce 
 
 Maple Sirup Apple Pie 
 
 Whole Wheat Bread Crullers 
 
 Hot Biscuits Coffee 
 
 Toast Milk 
 
 Butter Tea 
 
 LUNCH 
 
 Chicken Soup 
 
 Shrimp Salad 
 
 Bread and Butter 
 
 Peaches and Cream 
 
 Corn Soup 
 
 Baked Beans 
 
 Hot Biscuit 
 
 Ice Cream 
 
 Vegetable Soup 
 
 Frankfurters 
 
 Soda Crackers 
 
 Cocoa Milk 
 
 Fruit Salad 
 
 Dill Pickles 
 
 Doughnuts 
 
 Soda Water 
 
 Potato Salad 
 
 Cheese 
 
 Chocolate Cake 
 
 Tea 
 
 DINNER 
 
 Consomm6 
 
 Boiled Ham with 
 
 Stuffed Peppers 
 
 Peach Pie 
 
 Clam Chowder 
 
 Spinach 
 
 Hearts of Lettuce 
 
 Vanilla Ice Cream 
 
 Pea Soup 
 
 Saddle of Lamb 
 
 French Dressing 
 
 Chocolate Ice Cream 
 
 Olives 
 
 Planked Steak 
 
 Lobster Salad 
 
 Grapes 
 
 Celery 
 
 Mashed Potatoes 
 
 Fruit Salad 
 
 Nuts 
 
 Pickles 
 
 Baked Potatoes 
 
 Waldorf Salad 
 
 Raisins 
 
 Fried Filet of Sole 
 
 Potatoes Lyonnaise 
 
 Italian Salad 
 
 Edam Cheese 
 
 Boiled Whitefish 
 
 Peas 
 
 Bread 
 
 Roquefort Cheese 
 
 Saratoga Chips 
 
 String Beans 
 
 Rolls 
 
 Tea 
 
 Roast Lamb with 
 
 Cauliflower 
 
 Butter 
 
 Cocoa 
 
 Brown Gravy 
 
 Beets 
 
 Strawberry Pie 
 
 Milk 
 
 Fried Chicken 
 
 Rice 
 
 Apple Pie 
 
 Coffee 
 
 What cooking does to foods. If we were to examine a 
 bit of raw potato under the microscope, we would find 
 that the starch contained in it was placed in little pockets 
 surrounded by thick walls. Examination of a bit of cooked 
 potato under the microscope will show quite a different 
 condition. The walls around the starch cells are broken 
 and the starch swelled and softened. Cooking breaks down 
 
no 
 
 THE USES OF FOODS 
 
 FOODS ADAPTED TO DIFFERENT AGES, CLASSIFIED ACCORDING TO WHAT 
 THEY Do FOR THE BODY 
 
 Numbers are placed after some foods to show that they do important work under the column 
 headings of those numbers. 
 
 FOOD PRIMARILY FOR GROWTH 
 
 FOOD PRIMARILY FOR HEAT AND WORK 
 
 AND REPAIR 
 
 (ENERGY) 
 
 I 
 
 II 
 
 III 
 
 IV 
 
 V 
 
 Rich in Protein 
 
 Rich in Mineral 
 Matter 
 
 Rich in Fats 
 
 Carbohydrates 
 Starches 
 
 Carbohydrates 
 Sugars 
 
 Builds and repairs 
 
 Builds bone 
 
 Stimulate 
 
 Yield energy; 
 
 Yield energy for 
 
 muscle 
 
 Body activities 
 
 growth 
 
 heat and work 
 
 heat and work 
 
 FOODS SUITABLE FOR INFANTS 
 
 Milk II, III, V 
 
 Milk I, III, V 
 
 Cream I. II 
 
 Gruels I, II 
 
 Orange juice 
 
 human, modified 
 
 Egg yolk I 
 
 used to enrich 
 
 made f r om 
 
 II 
 
 cow's 
 
 Orange juice, 
 
 cow's milk 
 
 oats, barley, 
 
 Prune juice 
 
 Beef juice II 
 
 Prune juice 
 
 
 whole wheat 
 
 II 
 
 FOODS TO BE ADDED AFTER THE FIRST YEAR 
 
 Milk II, III, V 
 
 Soups III, 
 
 Egg I, II 
 
 Breakfast foods 
 
 Prunes -- II 
 
 Eggs 11,111 
 
 Fruits V 
 
 Cream I, V 
 
 I, II 
 
 stewed ; in 
 
 Poultry II, III 
 
 Greens III 
 
 Whole milk - 
 
 Potatoes I 
 
 puddings 
 
 Meats II, III 
 
 Meat broths 
 
 I, II, V 
 
 Rice I 
 
 Apples II 
 
 (in limited 
 amounts) 
 
 with vege- 
 tables III 
 
 Butter II 
 
 Sweet potatoes 
 
 nVv 
 
 stewed ; 
 baked 
 
 FOODS SUITABLE FOR ANY ONE OVER FIVE YEARS 
 
 Fish II, III 
 
 Vegetables 
 
 Following fats Chestnuts 
 
 All fruits in 
 
 
 (green- 
 
 may be defi- { II 
 
 jam or pre- 
 
 Cheese II, III 
 
 leaved) 
 
 cient in fat Squash II 
 
 serves, and 
 
 
 Cabbage raw 
 
 solublesi Pumpkins V 
 
 candied or 
 
 Beef II, III 
 
 as a salad, as 
 
 which stim- 
 
 Bananas II, 
 
 glace^ 
 
 Veal II 
 
 vegetable 
 Cauliflower 
 
 ulate growth. 
 Use them in 
 
 V 
 Rice II 
 
 Apples II 
 Peaches II 
 
 
 Artichokes 
 
 cooking 
 
 a. Polished 
 
 Apricots II 
 
 Mutton II, III 
 
 Tomatoes 
 
 Oleomargarine 
 
 b. Rice flour 
 
 Raisins II 
 
 Pork II, III 
 
 Egg plant 
 Green peppers 
 
 II 
 Peanuts I, 
 
 Wheat prod- 
 ucts I, II 
 
 Dates and figs 
 
 
 (sweet) 
 
 II, IV 
 
 a. Flour 
 
 All jellies 
 
 Soybeans II, III, 
 
 Cucumbers 
 Onions 
 
 Suet 
 Goose fat 
 
 b. Macaroni 
 c. Cream of 
 
 Honey 
 replaces sug- 
 
 
 Beets and tur- 
 
 Chicken fat 
 
 wheat 
 
 ar in pre- 
 
 Peanuts II, III, 
 
 nips V 
 
 Mutton fat 
 
 d. Shredded 
 
 serves, can- 
 
 IV 
 
 Radishes 
 
 Clarified and 
 
 wheat 
 
 dies, and 
 
 
 Parsnips 
 
 mixed with 
 
 Corn products 
 
 cakes 
 
 Beans (dried) 
 
 Watermelon 
 
 suet or cot- 
 
 I, II 
 
 Molasses 
 
 II, IV 
 
 raw, pickled 
 
 tonseed oil 
 
 a. Corn meal 
 
 replaces sug- 
 
 
 Cantaloupe 
 
 it makes an 
 
 b. Corn flour 
 
 ar in candies 
 
 Lentils II, IV 
 
 Pickles of all 
 
 excellent 
 
 c. Hominy 
 
 and cakes 
 
 Peas (dried) II, 
 
 kinds 
 Fruits raw 
 
 butter sub- 
 stitute for 
 
 Barley products 
 
 Maple sugar 
 Grape juice 
 
 IV 
 
 or cooked 
 
 cookery 
 
 Rye products 
 
 II 
 
 
 Food value 
 
 Salt pork 
 
 I, II 
 
 All candies 
 
 Nuts II, III, IV 
 
 depends upon 
 amount of 
 
 Lard 
 Bacon I 
 
 Oat products 
 
 All sirups 
 Cane or beet 
 
 Cereals II, III, 
 
 sugar added 
 
 Olive oil 
 
 Buckwheat 
 
 sugar 
 
 IV 
 
 Dried fruits 
 
 Cottonseed oil 
 
 products - 
 
 Sweet cakes 
 
 
 and v e g e - 
 
 Peanut oil 
 
 I, II 
 
 I, II, III, 
 
 Gelatine 
 
 tables 
 
 Corn oil 
 
 Tapioca 
 
 Sweet desserts 
 
 From chart prepared by the Department of Home Economics University of Michigan. 
 
DIFFERENT METHODS OF COOKING lit 
 
 and softens the tough walls of the cells in vegetables, and 
 in the case of meats makes them less tough and renders 
 them more palatable, and thus helps in their digestion. 
 More than this, especially in meats, cooking destroys 
 organisms which might grow if taken into the body. 
 Thus cooking makes foods safe which otherwise might be 
 harmful. 
 
 Different methods of cooking. - In general there are 
 four principal ways of cooking foods, boiling, broiling, fry- 
 ing, and baking. In boiling we place the food in water and 
 heat to 212 degrees Fahrenheit. White of egg coagulates 
 or hardens above 140 F. An excellent method of cooking 
 eggs is therefore either to poach them in water just below 
 boiling or to place the eggs in a dish of boiling water, cover, 
 take off the stove and leave for seven minutes. They 
 will be found to be cooked and the white will be quite 
 digestible. Milk should not be boiled, for this injures 
 the protein. In making soups, where we wish to draw 
 the nutriment into the water, the material should be put 
 into cold water, brought to the boiling point, and then 
 boiled slowly. If we wish to keep the nutriment in the 
 material, it should be put at once into boiling water. 
 In roasting and broiling use a high temperature at first. 
 A hot fire should be used in cooking a steak so as to 
 keep the nutriment within the browned surface. A 
 seared covering prevents the escape of juices. Frying 
 is not a desirable method of cooking because fat is likely 
 to soak into the foods, thus rendering them less digest- 
 ible. In baking, the food should be placed in a hot oven 
 first and then the heat reduced so that the inside of 
 the substances can be cooked. Cooking starch at baking 
 temperature changes it to dextrin, which is more easily 
 
112 
 
 THE USES OF FOODS 
 
 digested than starch. The browning of the bread crust is 
 due to this change. 
 
 Fireless cooker. In these days nearly every household 
 is provided with a labor-saving device known as the tireless 
 cooker. An interesting home project would be the manu- 
 facture of such a cooker. The principle of the tireless cooker 
 
 is that of insulation. 
 
 '' The food to be 
 
 cooked is placed hot 
 in the metal con- 
 tainer inclosed in a 
 box with heat insu- 
 lating material filling 
 the space between it 
 and the outer part 
 of the box, while a 
 hot soapstone or 
 cast iron radiator 
 is placed under the container. In this way after the 
 covers are tightly fastened, the food cooks slowly, and its 
 flavor is preserved. In addition to this time and fuel are 
 saved. 
 
 Scoring my foods and dietary. Probably no score card 
 is more difficult for you to use than this one and yet none 
 is more important. If you can make this a summary of 
 what you have learned about the uses of foods and then 
 apply this knowledge in your daily life your time will have 
 been well spent. In this card you will doubtless find im- 
 portant matters that have not been touched. If you want 
 to add or subtract or change any part of the card do so and 
 have the class discuss the change with you, for in this way 
 you may do some real constructive work in science. 
 
 Fireless cooker. 
 
SCORING MY FOODS AND DIETARY 
 
 SCORE CARD. FOODS IN MY HOME 
 
 
 
 
 
 MY SCORE 
 
 
 EXCELLENT 
 
 FAIR 
 
 VERY POOR 
 
 
 TOTAL 
 
 A BAL- 
 
 Menu varies under 
 
 Variation 10% to 
 
 If any one group is 
 
 
 
 ANCED 
 
 10% from i (pro- 
 
 50% (5) 
 
 omitted (o) 
 
 
 
 DIET 
 
 tein): i (fat): 4 
 
 
 
 
 
 
 (carbohydrate) (10) 
 
 
 
 
 
 
 RIGHT DIET FOR OCCUPATION, SEASON, AND ENVIRONMENT. 
 
 
 
 More food for heavy work (2) Less protein in hot weather (2) More 
 
 
 
 watery foods in hot weather (i) More fats in cold weather (i) Milk at 
 
 
 
 all times (4) 
 
 
 
 FOODS 
 
 Meats broiled, 
 
 Fried meats not 
 
 Fried meats three 
 
 
 
 PROPERLY 
 
 roasted, never 
 
 more than once 
 
 times a week or 
 
 
 
 COOKED 
 
 fried (2) 
 
 a week (i) 
 
 more (o) 
 
 .... 
 
 
 
 Cereals well cooked 
 
 Uncooked prepared 
 
 No cereals (o) 
 
 
 
 
 (2) 
 
 cereals (i) 
 
 
 
 
 
 Vegetables boiled 
 
 Vegetables boiled 
 
 Vegetables under- 
 
 
 
 
 slowly in little 
 
 rapidly but done 
 
 cooked and rap- 
 
 
 
 
 water (2) 
 Puddings, no fried 
 
 d) 
 Fried desserts in- 
 
 idly boiled (o) 
 Fried desserts fre- 
 
 
 
 
 desserts or pies (2) 
 Raw foods thor- 
 
 frequently (i) 
 Raw foods usually 
 
 quently (o) 
 Raw foods never 
 
 
 
 
 
 oughly washed (2) 
 
 washed (i) 
 
 washed (o) 
 
 
 
 COST OF 
 
 Expensive cuts of 
 
 Expensive cuts of 
 
 Expensive cuts of 
 
 
 
 FOODS 
 
 meat omitted (2) 
 
 meat once a week 
 
 meat every day 
 
 
 
 CONSID- 
 
 
 (i) 
 
 (o) 
 
 
 
 ERED 
 
 Vegetables out of 
 
 Vegetables out of 
 
 Vegetables out of 
 
 
 
 
 season omitted 
 
 season twice a 
 
 season regardless 
 
 
 
 
 (2) 
 
 week (i) 
 
 (o) 
 
 
 
 
 Cereals and canned 
 
 Canned goods but 
 
 No substitutes for 
 
 
 
 
 vegetables used 
 
 never cereals sub- 
 
 fresh vegetables 
 
 
 
 
 when fresh ones 
 
 stituted for fresh 
 
 (o) 
 
 
 
 
 are high (2) 
 
 vegetables (i) 
 
 
 
 
 
 Cheap fruits used 
 
 Expensive fruits 
 
 Expensive fruits 
 
 
 
 
 (2) 
 
 infrequently (i) 
 
 often used (o) 
 
 
 
 
 Home produced 
 
 Home grown foods 
 
 Home grown foods 
 
 
 
 
 foods used (2) 
 
 infrequent (i) 
 
 never used (o) 
 
 
 
 EASILY 
 
 Foods selected 
 
 Foods sometimes 
 
 Foods never se- 
 
 
 
 DIGESTED 
 
 every day for vi- 
 
 selected for vi- 
 
 lected for vitam- 
 
 
 
 FOODS 
 
 tamines (i) 
 
 tamines (A) 
 
 ines (o) 
 
 
 
 SELECTED 
 
 Fruit on menu 
 
 Fruit on menu 
 
 Fruit infrequently 
 
 
 
 
 twice a day (2) 
 
 once a day (i) 
 
 on menu (o) 
 
 
 
 
 Milk on menu three 
 
 Milk on menu once 
 
 Tea or coffee in- 
 
 
 
 
 times a day for 
 
 a day for chil- 
 
 stead of milk (o) 
 
 
 
 
 children under 15 
 
 dren; no tea or 
 
 
 
 
 
 (2) 
 
 coffee (i) 
 
 
 
 
 
 Cereals and bread 
 
 Cereals or bread 
 
 Cereal rarely used 
 
 
 
 
 used frequently 
 
 once a day only 
 
 (o) 
 
 
 
 
 (i) 
 
 (i) 
 
 
 
 
 
 Rice or potatoes 
 
 Rice or potatoes 
 
 Rice or potatoes 
 
 
 
 
 used frequently 
 
 infrequently (A) 
 
 used rarely (o) 
 
 
 
 
 (i) 
 
 
 
 
 
 
 No rich desserts (i) 
 
 Infrequent (5) 
 
 Frequent (o) 
 
 
 
 
 Have learned to 
 
 Have learned a few 
 
 Have learned them 
 
 
 
 
 omit foods I do 
 
 foods I cannot di- 
 
 but continue to 
 
 
 
 
 not digest (i) 
 
 gest (|) 
 
 eat them (o) 
 
 
 
 
 Laxative foods once 
 
 Laxative foods in- 
 
 Laxative foods not 
 
 
 
 
 a day (i) 
 
 frequently (5) 
 
 considered (o) 
 
 
 
 GRAND TOTAL 
 
 H.-WHIT. CIV. SCI. IN THE HOME 8 
 
H4 THE USES OF FOODS 
 
 REFERENCE BOOKS 
 
 Broadhurst, Home and Community Hygiene, Chapter III (Teacher's use). J. B. 
 Lippincott Company. 
 
 Bulletin 13, American School of Home Economics, Chicago. 
 
 Human Nutrition, Bulletins 6 and 7. Cornell Reading Course. 
 
 Davison, The Human Body and Health. American Book Company. 
 
 Fisher and Fisk, How to Live, Chapter II. Funk and Wagnalls. 
 
 Hunter, A Civic Biology, Chapters XIX, XX. American Book Company. 
 
 Hunter, Laboratory Problems in Civic Biology (For teachers). American Book 
 Company. 
 
 Lusk, Food in War Time. W. B. Saunders Company. 
 
 Ritchie, Physiology and Sanitation, Chapters VII, VIII, IX. World Book Com- 
 pany. 
 
 Rose, Feeding the Family. The Macmillan Company. 
 
 Stiles, Nutritional Physiology (For teachers). W. B. Saunders Company. 
 
 Stiles, Human Physiology, Chapters XXV, XXVI. W. B. Saunders Company. 
 
CHAPTER VII 
 
 PURE FOOD IN THE HOME 
 
 Problems. i. To learn what causes food to spoil. 
 
 2. To find out how yeast assists in bread making. 
 
 3. To discover methods of keeping foods for long periods 
 of time. 
 
 4. Why is there a difference in the efficiency of different 
 refrigerators ? 
 
 5. To discover the most favorable conditions for the growth 
 of bacteria. 
 
 Experiments. i. How and why yeast is used in bread making. 
 
 2. What conditions are favorable and what unfavorable for the growth 
 of bacteria? 
 
 3. What effects have different preservatives upon bacteria? 
 
 Project I. TESTING AND PRESERVING EGGS FOR HOME USE. 
 
 1. TESTING. Devise means for testing quality of eggs. (Candling; 
 10% brine solution.) Make test of fresh, stale, and good storage 
 eggs. (See United States Department Agriculture, Farmers' Bulle- 
 tin No. 471, and Sherman's Food Products, page 144.) 
 
 2. PRESERVING. Methods in use? Principle of preservation? 
 Why must fresh, clean, and unwashed eggs be used when preserving 
 in water glass? 
 
 3. COST OF EGG SUPPLY. Prices paid for eggs at different sea- 
 sons? 'How many eggs in a year? What saving would be made by 
 preserving three fourths of this supply? 
 
 "S 
 
n6 PURE FOOD IN THE HOME 
 
 Project II. To PASTEURIZE YOUR HOME MILK SUPPLY. 
 
 If your milk is purchased is there any evidence to indicate whether 
 or not it has been pasteurized? What is the evidence? Reasons why 
 you prefer pasteurized milk? Devise apparatus for pasteurization. 
 What temperature will you use? Give in your report a full account 
 of new facts learned, diagram of apparatus, and results secured. 
 
 Thought Question. 
 
 In a test, 50 pounds of ice were put into the refrigerator on a warm, 
 muggy day. The refrigerator was opened when necessary to put 
 in and to take out food. All the drip water going from the re f rig- 
 erator was saved and weighed. It weighed more than 50 pounds. 
 Explain why. 
 
 Why foods spoil. We are well aware that foods do not 
 keep indefinitely. Peaches, pears, and apples rot; eggs, 
 meat, and fish spoil; and milk and cooked cereals become 
 sour. Why does this happen? We know that if foods 
 are placed in the ice box they will not spoil so soon. We 
 know that if we boil certain kinds of foods they are less 
 likely to spoil, and we are all familiar with the use of canning 
 as a means of keeping foods ; but why do foods become 
 unfit for use eventually ? Take small quantities of several 
 different kinds of foods, for example, milk, a piece of 
 meat, potatoes, and cooked cereal, divide each food into 
 two equal portions, and place in separate dishes or jars; 
 seal tight. Place these jars in a large dish of water 
 and boil them for one hour. After this boiling we are sure 
 that everything that might have been living in the jars is 
 dead. If we now open one jar of each food, keeping the other 
 closed, and examine their contents after four or five days, 
 we shall find that in the open jars, the food has begun to 
 spoil, while in the closed jars, it is still good. Comparing 
 this with our previous experiments with the air, we may 
 conclude that whatever causes the food to spoil must come 
 
YEASTS AND WHAT THEY DO 
 
 117 
 
 from the air which is in contact with the food. As a matter 
 of fact this is true. The tiny plants of the home yeasts, 
 molds, and bacteria are always present in the air, al- 
 though we cannot see them, and when they lodge on food 
 and grow, they cause certain changes to take place in the 
 food. These changes cause the food to have an unpleasant 
 taste and odor. In fact, its quality is so changed that it is 
 no longer suitable to eat. 
 
 Yeasts and what they do. All boys and girls who live 
 in the country know that apple juice or grape juice, if 
 allowed to stand exposed to the 
 air, will very soon ferment, that 
 is, little bubbles will appear in 
 the liquid, and a prickly, pun- 
 gent taste is noticeable. The 
 yeast changes the sugars in the 
 fluid to alcohol and carbon di- 
 oxide is formed. The escaping 
 bubbles of this gas may be seen 
 as the liquid ferments. Yeasts 
 are tiny plants made up of a 
 single cell or unit of building material. They grow very 
 rapidly under favorable cond'tions. These conditions can 
 be easily shown by a home experiment. 1 Yeasts are useful 
 in commercial industries which make use of fermentation. 
 They are of great value also in the home in causing bread 
 to rise. 
 
 Experiment. How and why yeast is used in bread making. 
 
 Materials: Flour. Water. Sugar. Salt. Lard. Yeast cake. Bak- 
 ing tins. 
 Method: Make a dough by mixing the flour, sugar, salt, lard, and water 
 
 1 See Hunter's Civic Biology, page 137. 
 
 Yeast plant. 
 
Ii8 PURE FOOD IN THE HOME 
 
 to form a thick paste. Add a little yeast which has been mixed with 
 lukewarm water. Divide this into three parts. Keep the first of 
 these at a temperature of 85 to 90 degrees, the second in a cold tem- 
 perature, and the third at the room temperature, say about 70 degrees, 
 for several hours. Then bake the three samples. 
 
 Observation: Compare the three lots for appearance, texture, and taste. 
 
 Conclusion: How do you account for the pores in the bread? What 
 caused the bread to rise? Under what conditions does the rising take 
 place best? 
 
 Bread making. Most of us are familiar with the pro- 
 cess of bread making. The materials used are flour, milk 
 or water or both, salt, some butter or lard, a little sugar 
 and yeast. The sugar hastens the process of fermenta- 
 tion, or " rising," as it is called. After mixing the mate- 
 rials thoroughly, the dough is put in a warm place (about 
 75 Fahrenheit) to "rise." If we examine the dough after 
 some hours, we find it filled with holes, which give the mass 
 a spongy appearance. The yeast plants, owing to favorable 
 conditions, have grown rapidly and made the cavities with 
 carbon dioxide. Alcohol is present, too, but this is evapo- 
 rated when the dough is baked. The baking cooks the 
 starch of the bread, drives off both the carbon dioxide and 
 alcohol, and kills the yeast plants, besides forming a crust 
 on the loaf. 
 
 Molds in the home. One of the most common enemies 
 of food in the home is mold. If you place two pieces of 
 bread, one kept moist, and the other dry, side by side in 
 the kitchen or living room, the dry bread will remain un- 
 changed and a fuzzy growth will soon appear on the moist 
 bread. This fuzzy growth later turns black. This growth 
 is composed of a large number of little mold plants (see 
 figure) which take root on the surface of the bread, obtain 
 their food from it, grow in time so as to cover it, and produce 
 
CONDITIONS FOR THE GROWTH OF BACTERIA 119 
 
 little upright fruiting bodies. These fruiting bodies bear 
 tiny little seedlike structures, called spores, which are 
 blown around in the air, and grow under favorable condi- 
 tions. What are these conditions? Refer to your two 
 pieces of bread. Warmth and moisture are necessary for 
 the growth of all tiny organisms. Molds do considerable 
 damage, although 
 they do not render 
 foods completely un- 
 fit to eat. You all 
 remember scraping 
 the layer of mold 
 from cheese, before 
 using it. As a mat- 
 ter of fact, certain 
 cheeses get their 
 flavor from the 
 molds that grow in 
 them. Molds also 
 attack other organic 
 materials besides 
 foods. They grow 
 on shoes, leather, paper, or even moist wood. At least one 
 troublesome skin disease, called ring worm, is due to the 
 growth of molds in the skin. 
 
 Conditions favorable for the growth of bacteria. By far 
 the most important enemies of pure foods are bacteria, which 
 cause food to decay. We can show the factors which in- 
 fluence the growth of bacteria by the following experiment : 
 
 Experiment. What conditions are favorable and what unfavorable to the 
 
 growth of bacteria ? 
 Materials: Beans. Test tubes. 
 
 Three different types of mold plant. Notice the fruit- 
 ing bodies, containing spores, i. Cheese mold. 
 2. Corn smut. 3. Bread mold. 
 
120 PURE FOOD IN THE HOME 
 
 Method: Soak half of the beans in water overnight. Crush them and 
 place a portion in each of three different test tubes. Add a few drops 
 of water to each test tube. Place one of these test tubes where it will 
 be kept warm, about 90 degrees. Place another in the refrigerator, 
 close the third with a wad of cotton and heat to the boiling point. 
 Crush one or two of the dried beans and put them in a test tube in a 
 warm place. Compare the odor in these tubes in three days. 
 
 Conclusion: In which ones is decay taking place? Is this due to action 
 of bacteria ? Why do you think so ? Name at least two conditions 
 which favor bacterial growth and two conditions which are unfavorable 
 to it. 
 
 The experiments show us that bacteria need moist 
 food and a warm temperature in order to grow well. Grains, 
 crackers, dried fish, and dried fruits all are examples of 
 foods which keep well because they contain very little water. 
 Boiling or sterilizing kills bacteria. It can be shown that 
 they need air, and that light is unfavorable for their rapid 
 growth. Sunlight is known to be one of the best germ 
 killers we have. For that reason sunlight is important in 
 both sleeping and living rooms. 
 
 Foods most easily spoiled by bacteria. If you were 
 to select a large number of different foods and test them 
 to determine in which bacteria grow most rapidly, you 
 would find that the foods containing moisture; and a large 
 amount of protein, are most favorable for bacterial growth. 
 As the bacteria feed on this protein, it falls to pieces and 
 eventually rots. It is broken down by the action of bac- 
 teria into gases, liquids, and some solids. It has a char- 
 acteristic " rotten " odor, and poisons which come as a 
 result of the work of the bacteria. Some of the poisons 
 are called ptomaines. No food should be eaten that 
 smells badly or appears to be decayed. The use of com- 
 mon household preservatives in checking bacterial action 
 may be seen from this experiment. 
 
HOW TO KEEP GERMS FROM SPOILING FOODS 121 
 
 Experiment. What effect have different preservatives upon bacteria ? 
 
 Materials: Beans. Test tubes. Salt. Sugar. Vinegar. Boric acid. 
 
 Method: Soak beans in water overnight and crush them. Put a portion 
 into each of seven test tubes. Add water to cover. Set one tube 
 aside; add preservatives as follows: No. i, untreated; No. 2, one 
 fourth teaspoonful of salt; No. 3, one fourth teaspoonful of sugar; 
 No. 4, one teaspoonful of sugar; No. 5, one fourth teaspoonful of 
 vinegar; No. 6, one teaspoonful of vinegar; No. 7, a pinch of boric 
 acid. Leave these tubes open in a warm room. A bad odor will 
 result from bacterial growth. Test for odors every two days for 
 two weeks. Make tabulated form for recording the result of the test. 
 
 Preservatives and their use. Foods are often protected 
 against bacteria by adding substances in which bacteria 
 cannot live and develop. Such materials as salt, sugar, 
 vinegar, and some 
 spices are harmless 
 preservatives. In re- 
 cent years, other sub- 
 stances, such as ben- 
 zoate of soda, borax, 
 or boracic acid have 
 come to be used 
 as preservatives, but 
 the latter materials 
 are harmful, espe- 
 cially when used in 
 large quantities. 
 
 How may we keep 
 germs from spoiling 
 foods ? From the 
 
 Cold storage meat warehouse. 
 
 experiments that we 
 
 have performed, we 
 
 find that intense heat and intense cold prevent the growth 
 
 of germs. Bacteria are prevented from growing in foods 
 
122 
 
 PURE FOOD IN THE HOME 
 
 SECTION -THROUGH WALI/ 
 
 
 while kept in cold storage from six months to two years or 
 more. But we must remember that intense cold, while it 
 prevents the growth of bacteria, does not kill them, and 
 
 cold storage foods, if 
 placed in favorable 
 conditions for the 
 growth of germs, will 
 soon spoil. On the 
 other hand, heat if 
 continued long 
 enough kills bacte- 
 ria; and no germs 
 will grow in foods 
 thus heated pro- 
 vided they are kept 
 from air which con- 
 tains germs. With a 
 knowledge of these 
 facts we can better 
 understand the prin- 
 ciples underlying the 
 
 use of the ice box, 
 cold storage, and 
 canning. 
 
 Value of the re- 
 frigerator in the 
 home. We have 
 
 Circulation of air in the refrigerator. What foods are 
 placed below the ice chamber ? Why ? 
 
 seen that warm, moist air helps germs to grow, and decay 
 to take place. The refrigerator prevents this decay by sur- 
 rounding foods with dry, cold air. Left-overs which other- 
 wise would be wasted are thus saved for use, and foods 
 and drinks are made more palatable. 
 
HOW TO USE THE ICE BOX 123 
 
 Construction of the refrigerator. The household re- 
 frigerator is really a large box with thick, heat-insulating 
 walls, and with doors or covers to the several compart- 
 ments inside. There is always one chamber for the ice, 
 and several others with shelves for food. All of the 
 compartments within are connected by air ducts or 
 spaces, so that there is a free circulation of air through- 
 out the entire refrigerator. The drainage pipe leads to 
 a pan, or to a waste pipe. This drainage pipe is pro- 
 tected by a trap which prevents warm air from coming 
 in. The wall is of much importance; one of the best 
 is made of layers suggested in the diagram. If heat 
 enters this wall, it must go through all of these insulating 
 substances. 
 
 How to use the ice box. When air comes in contact 
 with ice, it gives up heat to the ice, and becomes colder and 
 heavier, and sinks to the bottom of the ice chamber. 
 An outlet below the ice allows this cold air to pass out at 
 one side to the bottom part of the refrigerator, where warm 
 food substances give off their heat to the cold air, which is 
 warmed and gradually rises, passing in again at the top 
 of the ice chamber. Thus we have a circulation of air 
 within the ice box. 
 
 The warm air, returning to the ice, causes some of it to 
 melt, and the heat is thus carried off in the water which 
 drips out into a drain outside. Since most foods have more 
 or less odor, we must place those which give off the most 
 odor at the top of the ice chest where, the air is warmer, 
 while meats, milk, and butter should be placed in the 
 coldest part of the ice box, where they will not take the 
 odor from other things. If you want your ice box to be 
 cold inside, do not cover the ice with newspapers or a woolen 
 
124 
 
 PURE FOOD IN THE HOME 
 
 blanket. If you desire to keep 
 the ice, and not the food, then 
 this is the way to do it. 
 
 The iceless refrigerator. An 
 interesting home project is the 
 making of an iceless refrigerator. 
 Directions may be found in the 
 U. S. Dept. of Agriculture pam- 
 phlet, Food Thrift Series, No. 4. 
 The principle of evaporation and 
 transfer of heat from the inside 
 to the outside of the box explains 
 its value. Study the diagram 
 and see how it might be usefully 
 applied to your own home. 
 
 Thermos bottle. The ther- 
 mos bottle, as a study of the 
 diagram will show, is another applica- 
 tion of insulation. It is essentially a 
 double walled bottle or one bottle in- 
 side of another, with a vacuum space 
 between. A vacuum is a better insu- 
 lator than air. The inside walls of 
 the bottles surrounding the vacuum 
 are mirrors. They reflect radiant heat 
 energy and prevent its passage across 
 the vacuum. Thus the thermos bot- 
 tle keeps cold substances cold, and hot 
 substances hot, by means of insulation. 
 Canning foods. Canning is simply 
 a method by which foods are boiled to kill the bacteria in 
 them and then placed in vessels into which no more bacteria 
 
 The iceless refrigerator. The out- 
 side canvas dips into a pan of 
 water at the top and drains into 
 another pan at the bottom of the 
 refrigerator. (U. S. Dept. Agri.) 
 
PASTEURIZATION OF MILK 
 
 125 
 
 Section of thermos bottle. 
 (After Hoadley.) 
 
 can gain entrance. This is done 
 usually by boiling fruits or vege- 
 tables, sometimes with sugar or 
 salt, and placing them immediately 
 in sterile jars and then sealing them 
 tightly. They may also be canned 
 by simply placing food uncooked 
 but clean in cans, closing the cans, 
 and then sterilizing by boiling for 
 a considerable period of time. The 
 United States Government, De- 
 partment of Agriculture, Farmers' 
 Bulletin No. 839 gives full direc- 
 tions for canning by this last method, called the cold-pack 
 process. Some vegetables such as peas, beans, and corn are 
 very difficult to can, probably because of spores of bacteria 
 
 which are attached to them, and 
 it requires a longer heating to kill 
 the spores. Fruits, on the other 
 hand, are usually much easier to 
 sterilize. The main thing to bear 
 in mind is to have the jars as well 
 as the material that goes into 
 them, sterilized, that is, absolutely 
 free from all living matter. This 
 can be done best by long boiling. 
 Pasteurization of milk. Milk 
 is one of the favorite foods of 
 bacteria. It is also a very im- 
 portant food for children, and 
 since a baby's digestive system 
 is easily upset, we should pro- 
 
 Pasteurizing apparatus, an arrange- 
 ment by which milk is conven- 
 iently heated to destroy disease 
 germs. The thermometer tells 
 the degree of heat used. 
 
126 
 
 PURE FOOD IN THE HOME 
 
 tect it by having the milk as free from germs as possible. 
 All milk contains some germs, even shortly after taken from 
 the cow, the most numerous being those which cause milk 
 to sour. To kill the harmful bacteria and not injure the 
 milk, a method known as pasteurization is used. This pro- 
 
 A model kitchen. 
 
 cess is named after the great French scientist, Louis 
 Pasteur, who did so much to apply his knowledge of harm- 
 ful germs to human betterment. By this method milk is 
 heated to a temperature of not over 150 degrees Fahrenheit 
 for a period of ten minutes to one half hour. The diagram 
 at the bottom of page 125 shows an excellent home pas- 
 teurization apparatus. In cities most milk delivered to 
 the home has been pasteurized, because the milk is some- 
 times forty-eight hours old before it is delivered to cus- 
 tomers. 
 
A CLEAN KITCHEN NECESSARY 
 
 127 
 
 Flavors in foods. Foods frequently get a large part of 
 their flavor from the bacteria which live in them. The flavor 
 of butter, the "gamey " taste of certain meats, the flavor of 
 sauerkraut, are due to the work of bacteria. Bacteria have 
 some useful, as well as harmful, effects in foods. 
 
 A clean kitchen necessary. Since foods are handled in 
 the kitchen, it goes without saying that a clean kitchen 
 will go a long way to pre- 
 vent spoiling of foods. This 
 means that all surfaces in 
 the kitchen should be washed 
 frequently. Why? Tables 
 and shelves should be cov- 
 ered with oil cloth or some- 
 thing which can be wiped off 
 and dried quickly. Wooden 
 surfaces, especially when 
 they become greasy, make 
 excellent homes for bacteria. 
 Remember that hands must 
 
 NUMBER OF BACTERIA LEfT ON A- 
 AfTER DIFFERENT METHOD? OF WASHING 
 
 259,000 
 
 i. As plate leaves table. 2. Washed in 
 
 B*r,J2- 
 
 Was " 
 
 be kept clean when handling 
 
 foods. Since flies carry dis- 
 
 ease the kitchen should be 
 
 screened. Dishes should be 
 
 washed clean with plenty of 
 
 soap and hot water. The accompanying diagram will 
 
 illustrate how the clean washing of dishes helps in keeping 
 
 bacteria from foods. 
 
 An excellent method of drying is to stack the dishes on the 
 draining board and then to pour boiling water over them. 
 Why is this better than drying them with a hand towel ? Is it 
 a good plan to leave the dishes to drain overnight ? Why not ? 
 
128 
 
 PURE FOOD IN THE HOME 
 
 Hints on the use of this score card. We are all in- 
 terested in keeping well and strong. We all like good 
 things to eat, too. Study the conditions in your home, 
 suggested by each item in the score card. Be fair in your 
 marking. The purpose is not to see who can get the 
 highest score but to show each one of you just what con- 
 ditions surround you and to suggest those things which 
 need correction the most. 
 
 SCORE CARD. PURE FOOD IN MY HOME 
 
 
 
 
 
 MY SCORE 
 
 
 EXCELLENT 
 
 FAIR 
 
 VERY POOR 
 
 
 Tota.1 
 
 CLEANLI- 
 
 Closed closet for 
 
 Closed closet; 
 
 No closet for dishes 
 
 
 
 NESS IN 
 
 dishes Glass 
 
 wooden doors (i) 
 
 (o) 
 
 
 
 THE CARE 
 
 doors (2) 
 
 
 
 
 
 OF FOOD 
 
 Dishes scalded, 
 
 Dishes dried with 
 
 Dishes not scalded 
 
 
 
 
 drained dry (2) 
 
 clean towel (i) 
 
 (o) 
 
 
 
 
 Wash hands with 
 
 Sometimes remem- 
 
 Never wash hands 
 
 
 
 
 soap and water 
 
 ber to wash 
 
 before handling 
 
 
 
 
 before handling 
 
 hands (i) 
 
 food (o) 
 
 
 
 
 food (3) 
 
 
 
 
 
 
 Kitchen table, floor, 
 
 Table, woodwork, 
 
 Kitchen table, 
 
 
 
 
 woodwork, and 
 
 floor, and walls 
 
 woodwork, floor, 
 
 
 
 
 walls always kept 
 
 usually clean (i) 
 
 and walls seldom 
 
 
 
 
 clean (3) 
 
 
 clean (o) 
 
 
 
 REFRIG- 
 
 Large enough to 
 
 Too small (i) 
 
 No refrigerator (o) 
 
 
 
 ERATOR 
 
 hold all food (2) 
 
 
 
 
 
 
 Enamel or porce- 
 
 Galvanized iron or 
 
 Rough or cracked 
 
 
 
 
 lain lining, easily 
 
 zinc interior (i) 
 
 interior (o) 
 
 
 
 
 cleaned (2) 
 
 
 
 
 
 
 Economical of ice, 
 
 Wasteful of ice (i) 
 
 Does not keep ice 
 
 
 
 
 good circulation 
 
 
 or food ; poor in- 
 
 
 
 
 (2) 
 
 
 sulation (o) 
 
 
 
 
 Food properly 
 
 Food in part prop- 
 
 No knowledge of 
 
 
 
 
 placed to show 
 knowledge of con- 
 
 erly placed. Some 
 foods spoil or 
 
 convection cur- 
 rents shown (o) 
 
 
 
 
 vection currents 
 
 taste (i) 
 
 
 
 
 
 (2) 
 
 
 
 
 
 
 Washed thoroughly 
 twice a week (2) 
 
 Washed thoroughly 
 once a week (i) 
 
 Washed irregularly 
 Has odor (o) 
 
 
 
 STERILI- 
 
 Left-overs heated 
 
 Some left-overs 
 
 No left-overs saved 
 
 
 
 ZATION 
 AND 
 
 to boiling point 
 to prevent spoil- 
 
 thrown away be- 
 cause of not being 
 
 (o) 
 
 
 
 PASTEURI- 
 
 ing (3) 
 
 sterilized (i) 
 
 
 
 
 ZATION 
 
 No fruits left to 
 
 Fruit occasionally 
 
 Fruit often spoils. 
 
 
 
 
 spoil (2) 
 
 spoils (i) 
 
 not cooked and 
 
 
 
 
 
 
 saved (o) 
 
 
 
 
 All milk left ov?r 
 
 Some milk scalded, 
 
 No milk saved (o) 
 
 
 
 
 scalded for cook- 
 
 some sours and is 
 
 
 
 
 
 ing (2) 
 
 thrown out (i) 
 
 
 
 
 
 Milk for children 
 
 No certified milk 
 
 No pasteurized or 
 
 
 
 pasteurized at 
 
 but town or city 
 
 certified milk (o) 
 
 
 
 
 home or certified 
 
 supply pasteur- 
 
 
 
 
 
 milk used (3) 
 
 ized (2) 
 
 
 
 
REFERENCE BOOKS 
 
 129 
 
 SCORE CARD. PURE FOOD IN MY HOME Continued 
 
 
 
 
 
 MV 5 
 
 )CORE 
 
 
 EXCELLENT 
 
 FAIR 
 
 VTTPV Pnrn? 
 
 
 
 
 
 
 
 
 Total 
 
 USE OF 
 
 Proper knowledge 
 
 Somo food wasted 
 
 Much food wasted 
 
 
 
 PRESERV- 
 
 of use of preserv- 
 
 because of lack of 
 
 (o) 
 
 
 
 ATIVES 
 
 atives shown. 
 
 knowledge (i) 
 
 
 
 
 
 No food wasted 
 
 
 
 
 
 
 (2) 
 
 
 
 
 
 
 Salt or waterglass 
 
 Salt or waterglass 
 
 Salted food not 
 
 
 
 
 used in preserv- 
 
 sometimes used 
 
 used; Eggs not 
 
 
 
 
 ing foods (2) 
 
 in preserving 
 
 preserved (o) 
 
 
 
 
 
 food (i) 
 
 
 
 
 
 All extra supplies 
 of vegetables and 
 
 Part of extra supply 
 canned (i) 
 
 None of extra sup- 
 ply canned (o) 
 
 
 
 
 fruits canned (2) 
 
 
 
 
 
 
 Sugar used in pre- 
 
 Some fruits and 
 
 No homemade jel- 
 
 
 
 
 serving fruits (2) 
 
 jellies made, but 
 
 lies or preserves 
 
 
 
 
 
 not all utilized (i) 
 
 (o) 
 
 
 
 
 No harmful pre- 
 
 Use of preserva- 
 
 Preservatives other 
 
 
 
 
 servatives in 
 
 tives in some 
 
 than salt, sugar, 
 
 
 
 
 bought foods (2) 
 
 bought food 
 
 and vinegar in 
 
 
 
 
 
 shown by label 
 
 much food pur- 
 
 
 
 
 
 d) 
 
 chased (o) 
 
 
 
 PROTEC- 
 
 Perishable foods 
 
 Perishable foods 
 
 Much perishable 
 
 
 
 TION OF 
 
 kept cool (2) 
 
 sometimes kept 
 
 food wasted be- 
 
 
 
 FOODS 
 
 
 cool (i) 
 
 cause not kept 
 
 
 
 
 
 
 cool (o) 
 
 
 
 
 Foods kept covered 
 
 Foods sometimes 
 
 Foods often uncov- 
 
 
 
 
 (2) 
 
 covered (i) 
 
 ered (o) 
 
 
 
 
 Canned goods never 
 
 Canned goods 
 
 Canned goods often 
 
 
 
 
 left in cans after 
 
 sometimes left in 
 
 left in cans after 
 
 
 
 
 they are opened 
 
 cans (i) 
 
 opening (o) 
 
 
 
 
 All foods protected 
 
 Insects sometimes 
 
 Insects often in 
 
 
 
 
 from insect (2) 
 
 get in foods (i) 
 
 food (o) 
 
 
 
 
 Fly screens in win- 
 
 Fly screens in win- 
 
 No screens; many 
 
 
 
 
 dows; no flies in 
 
 dows ; a few flies 
 
 flies in house (o) 
 
 
 
 
 house (2) 
 
 in house (i) 
 
 
 
 
 
 
 
 
 
 
 GRAND 
 
 rOTAL 
 
 
 
 
 
 REFERENCE BOOKS 
 
 Allen, Civics and Health, Chapter XXV (For teachers). Ginn and Company. 
 Broadhurst, Home and Community Hygiene, Chapters I, III, IV (Teacher's use). 
 
 J. B. Lippincott Co. 
 Caldweil and Eikenberry, Elements of General Science, Chapter VIII. Ginn and 
 
 Company. 
 
 Clark. An Introduction to Science, Chapters IX, XIV. American Book Company 
 Conn, Bacteria, Yeasts and Molds of the Home. Ginn and Company. 
 Claycomb- Petri Dish Projects. School Science and Mathematics, April, 1918. 
 The Persistent Delusion of Ptomaine Poisoning. Current Opinion, April, 1918. 
 Hunter, A Civic Biology, Chapters XI, XXIV. American Book Company. 
 H.-WHIT. CIV. SCI. IN THE HOME Q 
 
130 PURE FOOD IN THE HOME 
 
 Hunter, Laboratory Problems in Civic Biology, Chapter XI (For suggested exper- 
 imental work). American Book Company. 
 
 McNutt, The Modern Milk Problem (For teachers). The Macmillan Company. 
 
 Official Handbook, Boy Scouts of America (Questions on decay). Doubleday, Page 
 and Company. 
 
 Public Health Service Bulletin 56, Milk and its Relation to Public Health. 
 
 Ritchie, Primer of Sanitation, Chapter XXX. World Book Company. 
 
 Milk, U. S. Department of Labor, Bulletin 35 Children's Bureau. 
 
 Van Buskirk and Smith, The Science of Everyday Life, Project X. Houghton 
 Miffiin Company. 
 
 Vulte and Vanderbilt, Food Industries, Chapter VIII. Chemical Publishing 
 Company. 
 
 Weed, Chemistry in the Home, Chapter XXIV. American Book Company. 
 
 Wing, Milk and Its Products (For teachers). The Macmillan Company. 
 
CHAPTER VIII 
 
 HOUSEHOLD PESTS AND HOW TO FIGHT THEM 
 
 Problems. i. To understand what harm is done by 
 household pests. 
 
 2. To learn the life history of some harmful insects. 
 
 3. To find how household pests can be exterminated. 
 
 Experiment. To work out the life cycle of the fly. 
 
 Project I. To EXTERMINATE FLIES FROM MY HOME. 
 
 1. Find details of various methods of getting rid of flies. Traps, 
 tanglefoot, poison papers, liquids, and powders. 
 
 2. Find details of means of preventing production of flies which 
 will be of value in your particular place. Care of breeding places. 
 
 3. Make a plan of campaign and carry it out. 
 
 4. Make a complete report of your project. State to what ex- 
 tent the fly nuisance has been abated. 
 
 Suggested Projects. 
 
 1. TO RID THE HOUSE OF RATS AND MICE. 
 
 2. TO WORK OUT METHODS OF FIGHTING OTHER HOUSEHOLD 
 PESTS. 
 
 3. TO PREPARE PROPER CONTAINERS, AND STORAGE SPACE FOR 
 CLOTHES, AND TO KEEP WINTER CLOTHING OVER SUMMER SAFE FROM 
 MOTHS. 
 
 What household pests do. What a pleasant place the 
 world would be to live in if it were not for the flies and mos- 
 quitoes which annoy us, fleas and bedbugs which bite us, 
 
132 HOUSEHOLD PESTS AND HOW TO FIGHT THEM 
 
 weevils and roaches to get into our foods, and rats and mice 
 to destroy our homes and damage our plants and crops. 
 
 Estimates made by the United States Department of 
 Agriculture show that over a billion dollars' worth of 
 damage is done each year to crops and other property in 
 this country by insects alone. An estimate is made that 
 at least a million dollars' damage a year is done by rats in 
 the city of Pittsburgh alone. But aside from these losses 
 the untold suffering and the many unnecessary deaths 
 caused by diseases which are carried by insects and other 
 
 Follow the fly. What happens ? 
 
 animals, should cause us to spend thought and time in 
 making homes as free as possible from these household 
 pests. Almost every day scientists discover some new 
 relation between insects and diseases. Many infectious 
 diseases depend in part, at least, upon insects as carriers. 
 The fly which to-day puts its dirty feet in baby's cup 
 of milk yesterday lived in a manure heap, and on the 
 way here may have stopped in a privy. This is not nice 
 to think about, but it is fact, nevertheless, and every think- 
 ing boy and girl should realize these things. 
 
 The house fly in relation to our home. It is estimated 
 that while snakes kill perhaps two or three people every 
 year in the United States, house flies are responsible for 
 
THE HOUSE FLY IN RELATION TO OUR HOME 133 
 
 the deaths of about 100,000 people. This is due to the filthy 
 habits of flies. Probably most of the dysentery and sum- 
 mer complaint, especially of babies, is due directly to flies, 
 for they carry directly to baby's milk on their legs or bodies 
 germs which they have 
 taken from some other 
 sick baby or person hav- 
 ing the disease. 
 
 Typhoid fever, a well- 
 known disease, responsi- 
 ble for a great many 
 deaths, especially in 
 country districts, is un- 
 doubtedly largely spread 
 by means of flies. A 
 study of the accompany- 
 ing diagram will show 
 clearly that the warm 
 weather, spread of ty- 
 phoid, and diarrhoea are coincident with fly time. A 
 knowledge of the life history of the fly will help us to 
 combat the pest. 
 
 Experiment. To work out the life history of the fly. 
 
 Materials: A small wire cage. A piece of stale meat. 
 
 Method: Leave the meat out in the open where there are plenty of flies 
 until you can see fly eggs, then cover it with a wire cage and keep it 
 in a warm place. 
 
 Observation: Look at it every few days. What different stages follow 
 the egg stage ? How long does it take each stage to develop ? Do you 
 think temperature would have any effect on the rapidity of develop- 
 ment? 
 
 Conclusion: What is the life cycle of the fly? 
 
 Application: Does this experiment suggest any method of control of the 
 number of flies about the house ? 
 
 There were 329 cases of typhoid in Jacksonville, 
 Florida, in 1910; 158 in 1911; and 87 in the 
 first 10 months of 1912. During the winter of 
 1910-1911, 80 to 85 % of the outdoor toilets 
 were made flyproof . How would you account 
 for the great decrease in cases of typhoid in- 
 dicated in 1911 and 1912 ? 
 
134 HOUSEHOLD PESTS AND HOW TO FIGHT THEM 
 
 How to get rid of flies. In order to rid our houses of 
 these pests it is necessary to know something about the 
 habits of flies. Flies commonly breed in manure, but 
 sometimes in garbage which has been allowed to stand 
 in uncovered cans and in rotting masses of paper and other 
 rubbish, provided it is moist. A fly does not take more 
 than ten days to complete its life history in warm weather. 
 The eggs hatch in about eight hours into maggots. 
 
 These whitish 
 wormlike animals 
 burrow into the 
 manure pile and 
 there after six or 
 seven days become 
 brown pupae, and 
 hatch out three 
 days later as adult 
 flies. Since an 
 adult fly lays 
 about one hun- 
 dred and fifty eggs 
 at a time, and about one half of all flies are females, it is not 
 difficult to estimate how many flies might come from one pair 
 in a season. Hodge has estimated that within three months 
 the offspring from one fly would amount to 143,675 bushels 
 of flies. If these figures are correct, it is evident that 
 " swatting the fly " or using screens will not do much good 
 unless the flies are " swatted " early in the season when there 
 are not very many which have lived through the winter. 
 Evidently the best things to do are to destroy the breeding 
 places of flies and to trap as many as possible. All manure 
 heaps should be worked over and scattered at least once 
 
 Life history of house flies, showing from left to right the 
 eggs, larvae, pupae, and adult flies. (Photograph about 
 natural size, by Overton.) 
 
MOSQUITOES 
 
 135 
 
 A fly trap. 
 
 every ten days so that the flies cannot have a chance to 
 breed. Garbage and any material that might form a breed- 
 ing place should be carefully removed within the ten-day 
 period. One of the best baits for flies is made by adding 
 to a pint of milk and 
 water two tablespoon- 
 fuls of formaldehyde. 
 Place a piece of bread 
 in a shallow dish and 
 almost cover it with 
 the poisonous dose. An 
 excellent home project 
 would be the manu- 
 facture of an efficient 
 fly trap. The United 
 States Government bulletins, for example, Farmers' Bulle- 
 tin No. 927, or Hodge's Nature Study and Life give de- 
 scriptions of excellent traps. 
 
 In addition to the house fly, many other flies, as the 
 stable fly, the fruit fly, and the black fly, cause us great 
 annoyance, and some are believed to carry disease. 
 
 Mosquitoes. We have all at one time or another 
 been annoyed by mosquitoes. They render some parts 
 of cities and towns unfit for human residence, not only 
 because of their bite, but because they carry malaria. 
 The old belief that malaria was caused by bad air has 
 long been exploded, for experiments have proved that a 
 certain kind of mosquito, the anopheles, is responsible for 
 carrying this disease. A careful study of the diagram will 
 show how we can distinguish between the harmless culex 
 and the harmful anopheles. The harmful one, as you 
 notice, stands with its body oblique while the culex holds 
 
136 HOUSEHOLD PESTS AND HOW TO FIGHT THEM 
 
 its body parallel to the surface. Mosquitoes breed in water, 
 and unfortunately for us, rain barrels, roof gutters, or any 
 place where water remains for two weeks or more can 
 raise a large number of these nuisances. Their life his- 
 tory can be understood by studying the diagram be- 
 low. The common culex, the house mosquito, lays from 
 
 two hundred to four 
 hundred eggs. The 
 little wigglers which 
 come from the eggs live 
 in water, obtaining their 
 oxygen through a long 
 tube which sticks out of 
 the water when they go 
 to the surface to breathe. 
 It takes from two to 
 three weeks for the mos- 
 quito to complete its life 
 from the egg to the adult. 
 Since mosquitoes live 
 during this time under 
 water, and since they 
 must come to the surface 
 to get air, a simple way 
 to destroy them by pre- 
 venting their breathing 
 is to pour oil over the standing water in which they lay 
 their eggs. Sometimes it is necessary to drain swampy 
 areas where standing water makes breeding places, and 
 many households have been relieved from the plague of 
 mosquitoes by the simple removal of empty cans or bar- 
 rels which might hold water. Why not make a survey of 
 
 The four stages in the life history. Read from 
 top to bottom as follows: egg, larvae (wig- 
 glers), pupae, adult. At the left is seen the 
 culex; at the right, the harmful anopheles. 
 
LICE 137 
 
 your own house and grounds and make sure that no stand- 
 ing water is near, for mosquitoes rarely fly more than a 
 few hundred yards from where they hatch. The introduc- 
 tion of goldfish, sticklebacks, or other small fish will soon 
 rid ponds of mosquitoes. 
 
 Yellow fever, which at one time was a terrible menace in 
 this country, is carried by another kind of mosquito. We 
 will discuss this more fully in " Civic Science in the Com- 
 munity." 
 
 Fleas. The ordinary dog and cat flea should always be 
 considered a menace to health, for it may carry bubonic 
 plague and infect people with it. 
 Plague is a disease of rats, but is 
 spread by fleas which live upon them. 
 Fortunately this disease is not prev- 
 alent in this country, although in Flea which trai T smits bubonic 
 some parts of the world, particularly plague from rat to man. 
 in China, it is killing many thousands of people yearly. 
 Fleas flourish in dust, under carpets, in cracks, and par- 
 ticularly where dogs and cats sleep. Mats on which these 
 animals sleep should be constantly dusted and cleaned, 
 
 and benzene or pyrethrum powder may be used 
 
 to fight the pests. 
 Lice. Lice are wingless insects which have 
 
 come into prominence during the World War. 
 
 The body louse is the " cootie " of the soldier. 
 
 It becomes a very serious pest to those obliged 
 
 to live in dirty surroundings, and can be 
 The "cootie." era di ca t e d only by having the clothes sterilized 
 and by treatment of the body with ointments. The head 
 louse sometimes found in the heads of school children is very 
 annoying and hard to get rid of. The " nits " or eggs are 
 
138 HOUSEHOLD PESTS AND HOW TO FIGHT THEM 
 
 attached to hairs, and can only be removed after thoroughly 
 washing and combing. The application of larkspur is 
 found to kill the pests. 
 
 Bedbugs. Although the bedbug is usually found in 
 dirty homes, it may come from outside into clean houses. 
 Bedbugs move around only at night, and 
 their very flat bodies get into small crevices, 
 especially along wall boards and in wooden 
 beds, where they may become very annoy- 
 ing. They are much more active in hot 
 The bedbug. weather than in cold. While the bite is not 
 serious, it is believed sometimes to carry diseases. To rid 
 the house of bedbugs it is necessary to clean all furniture 
 and woodwork thoroughly. Every crack in the furniture 
 and floors should be treated with formalin or an insecticide 
 made particularly for destroying this pest. 
 
 Insects which attack food. Some household pests 
 are attracted to the house by our food. Cockroaches are 
 found usually around sinks or in food closets. They eat 
 almost anything, and are apt to be a great nuisance, al- 
 though the damage they do is not very great. 
 They are difficult to get rid of, as every house- 
 wife knows. They may be poisoned by feed- 
 ing them a mixture of sugar and powdered 
 borax. All cracks and crevices where they 
 hide should be sprayed with bisulphide of car- 
 bon which will kill them. They may be 
 
 . 11. The cockroach. 
 
 trapped by plating food in a deep dish into 
 
 which they may crawl by means of sticks, but from which 
 
 they cannot get out. 
 
 Ants also are very troublesome, as they destroy many 
 kinds of foods. The best way to rid the house of them is. 
 
INSECTS WHICH ATTACK CLOTHES 
 
 139 
 
 The ant. 
 
 to find their nest and pour into it a few ounces of carbon 
 
 bisulphide. (This is a dangerous liquid to handle, but 
 
 is less explosive than gasoline.) Colonies 
 
 of ants in the house may be treated also 
 
 with gasoline or boiling water, and the ants 
 
 may be kept from getting into the house 
 
 by placing a border of some substance that 
 
 they do not like, such as powdered borax, on 
 
 the threshold. Sulphonaphthol is another 
 
 efficient means of ridding the house of ants. 
 
 Insects which attack clothes. Two insects, clothes 
 moths and carpet beetles (Buffalo moth or Buffalo bug), 
 are pests which do much damage to stored materials, espe- 
 cially our clothes and rugs. The young, or larvae, feed 
 on the woolen and fur of the clothes, and do much damage 
 in this way. If these materials are well dusted and allowed 
 to hang outside in the sun a few hours before putting them 
 away for the summer, and then packed into tight boxes or 
 bags, they will not be troubled by moths. Moth balls and 
 
 camphor keep out 
 the insects, but do 
 not kill them, so that 
 if clothes are put 
 away with the in- 
 sect in them they 
 will not be pro- 
 tected. The carpet 
 beetle can be fought 
 It feeds on carpets 
 
 The clothes moth, i, eggs; 2, larva; 3, pupa; 
 4, adult. 
 
 in the same way as the clothes moth, 
 and other goods stored away. 
 
 Household insects may be grouped according to the 
 damage they do. The following experiment is suggested 
 
140 HOUSEHOLD PESTS AND HOW TO FIGHT THEM 
 
 that you may see which insects should be grouped to- 
 gether : 
 
 Experiment. To classify the insects of the home according to the harm 
 
 they do. 
 
 Make a list of all the household insect pests you can find out about. 
 List these under the suggested headings according to the harm they do. 
 Possibly some one insect will need to be listed in more than one column. 
 
 DISEASE CARRIERS 
 
 EATS AND DESTROYS 
 FOODS 
 
 ANNOYS AND BITES 
 
 DESTROYS TEXTILES 
 AND CLOTHING 
 
 
 
 
 
 The house rat. David Lanz of the Department of 
 Agriculture calls the rat the worst mammalian pest 
 known to man. Not only do they do many million dollars' 
 damage to grain stored in barns but they kill many 
 young chicks and destroy a great number of eggs. They 
 have been estimated to do $200,000,000 damage in the 
 United States every year. Buildings are damaged, water 
 pipes gnawed, and buildings flooded. Many fires are caused 
 by rats gnawing off the insulation of electric wires and by 
 setting off matches which they have taken to their nests. 
 In addition to this, rats are responsible for killing millions 
 of people in India and elsewhere lately by carrying the 
 germs of the bubonic plague, the " Black Death " of the 
 Middle Ages. 
 
 One of the practical projects a boy can work out is to lay 
 plans for the trapping of rats or killing them by means of 
 poison. One must remember that poisons are dangerous 
 to handle and that rats and mice are cunning, so that it 
 takes constant and careful work in order to finally rid the 
 
USE OF THE SCORE CARD 
 
 141 
 
 house or barn of these destructive pests. Concrete con- 
 struction which is rat proof is one of the latest and best 
 
 How the house rat does damage. (Photo of group in American Museum of Natural 
 
 History.) 
 
 methods of preventing rats from doing damage in the 
 home. The best proof that this chapter has not been 
 written in vain will be the home work of those who read 
 it. Let us all work together to make our homes safer 
 and better places in which to live. 
 
 Use of the score card. While it is not always pleasant 
 to admit that things are not as they should be, yet that 
 is a good way to begin and improvements are sure to fol- 
 low. If home conditions show up badly in this card, each 
 boy and girl should go to work at once to make them 
 better. Naturally you need not show the details of this 
 card to any one, although your total score might be given. 
 
142 HOUSEHOLD PESTS AND HOW TO FIGHT THEM 
 
 SCORE CARD. HOUSEHOLD PESTS 
 
 
 
 
 
 MY 
 
 SCORE 
 
 
 EXCELLENT 
 
 FAIR 
 
 VERY POOR 
 
 
 
 
 
 
 
 
 TOTAL 
 
 FLIES 
 
 No manure piles (2) 
 
 Manure pilrj pro- 
 tected (i) 
 
 Manure piles never 
 disinfected (o) 
 
 
 
 
 Garbage pail with 
 
 Garbage pails loose 
 
 Garbage pails no 
 
 
 
 
 tight cover (i) 
 Garbage pail scald- 
 
 covers (5) 
 Garbage pails scald- 
 
 cover (o) 
 Garbage pails scald- 
 
 
 
 
 ed twice a week 
 
 ed once a week 
 
 ed infrequently 
 
 
 
 
 in hot weather (i) 
 
 in hot weather (i) 
 
 (o) 
 
 
 
 
 No outdoor privies 
 
 Outdoor privies 
 
 Privies not screened 
 
 
 
 
 (2) 
 
 well screened (i) 
 
 (o) 
 
 
 
 
 No decaying refuse 
 
 Decaying refuse in 
 
 Yards with much 
 
 
 
 
 in yard (2) 
 
 yard occasionally 
 
 refuse (o) 
 
 
 
 
 
 (i) 
 
 
 
 
 
 All windows 
 
 Kitchen windows 
 
 No windows 
 
 
 
 
 screened (i) 
 
 screened (5) 
 
 screened (o) 
 
 
 
 
 Fly traps or poi- 
 
 Fly traps or poi- 
 
 No traps or poi- 
 
 
 
 
 sons and swatters 
 
 sons or swatters 
 
 sons; swatters 
 
 
 
 
 (i) 
 
 (any two) (J) 
 
 only used (o) 
 
 
 
 
 No culex (2) 
 
 Very few culex (i) 
 
 Many culex (o) 
 
 
 
 MOSQUI- 
 
 No anopheles (2) 
 
 Very few anopheles 
 
 Many anopheles (o) 
 
 
 
 TOES 
 
 
 d) 
 
 
 
 
 
 No breeding places 
 
 Breeding places not 
 
 Breeding places 
 
 
 
 
 of any kind (4) 
 
 near home (2) 
 
 near home (o) 
 
 
 
 
 
 All standing water 
 
 Standing water not 
 
 
 
 
 
 oiled regularly in- 
 cluding rain bar- 
 
 regularly oiled (o) 
 
 
 
 
 
 rels (i) 
 
 
 
 
 
 No mosquitoes in 
 
 Mosquitoes rare in 
 
 Many mosquitoes 
 
 
 
 
 house (2) 
 
 house (i) 
 
 in house at night 
 
 
 
 
 
 
 (o) 
 
 
 
 BODY 
 
 No fleas on cat or 
 
 Fleas on cat or dog 
 
 Fleas in carpets or 
 
 
 
 PESTS 
 
 dog in house (3) 
 
 not in rooms. 
 
 rugs. Children 
 
 
 
 
 
 Pets washed fre- 
 
 often bitten. 
 
 
 
 
 
 quently (2) 
 
 Dog or cat not 
 
 
 
 
 
 
 washed (o) 
 
 
 
 
 No bedbugs (3) 
 
 Bedbugs infre- 
 
 Bedbugs frequent. 
 
 
 
 
 
 quently found. 
 Insecticide used 
 
 Insecticide not 
 used (o) 
 
 
 
 
 
 frequently (2) 
 
 
 
 
 
 No head lice (3) 
 
 Children rarely 
 
 Children frequently 
 
 
 
 
 
 have head lice or 
 
 have head lice or 
 
 
 
 
 
 nits. Treatment 
 
 nits (o) 
 
 
 
 
 
 given frequently 
 
 
 
 
 
 
 (i) 
 
 
 
 
 
 No other body 
 
 Other body pests 
 
 Other body pests 
 
 
 
 
 pests (i) 
 
 sometimes found 
 
 frequent. Dirty 
 
 
 
 
 
 (i) 
 
 conditions o f 
 
 
 
 
 
 
 clothes or body 
 
 
 
 
 
 
 (o) 
 
 
 
 FOOD 
 
 No cockroaches or 
 
 Roaches or water 
 
 Roaches and water 
 
 
 
 AND 
 
 water bugs (2) 
 
 bugs infrequent. 
 
 bugs frequent ; 
 
 
 
 CLOTHES 
 PESTS 
 
 
 Constant care ex- 
 ercised. Insecti- 
 
 sink dirty; food 
 left around kitch- 
 
 
 
 
 
 cides used (i) 
 
 en ; no insecti- 
 
 
 
 
 
 ' 
 
 cides used (o) 
 
 
 
 
 No ants (2) 
 
 Ants sometimes in 
 
 Ants numerous ; 
 
 
 
 
 
 pantries; not in 
 
 much food 
 
 
 
 
 
 foods. Insecti- 
 
 spoiled by them 
 
 
 
 
 
 cides used (i) 
 
 (o) 
 
 
 
 
 
 
 
 
 
REFERENCE BOOKS 
 
 143 
 
 SCORE CARD. HOUSEHOLD PESTS Continued 
 
 
 
 
 
 MY S 
 
 CORE 
 
 
 T^Yr*1?T T T?MT 
 
 FAIR 
 
 Wuv POOP 
 
 
 
 
 
 
 
 
 TOTAL 
 
 FOOD 
 
 No weevils or other 
 
 Other insects de- 
 
 Much food thrown 
 
 
 
 AND 
 
 f o o d-destroying 
 
 structive to foods 
 
 out because of 
 
 
 
 CLOTHES 
 
 insect (2) 
 
 sometimes found 
 
 weevils or other 
 
 
 
 PESTS 
 
 
 00 
 
 insects. No care 
 
 
 
 
 
 
 taken (o) 
 
 
 
 
 No clothes moths 
 
 Clothes moths and 
 
 Clothes moths or 
 
 
 
 
 or Buffalo moths. 
 
 Buffalo moths 
 
 Buffalo moths 
 
 
 
 
 All precautions 
 
 do infrequent 
 
 do much damage 
 
 
 
 
 taken (2) 
 
 damage. Clothes 
 
 (o) 
 
 
 
 
 
 well cleaned and 
 
 
 
 
 
 
 put away with 
 
 
 
 
 
 No other insect 
 
 proper care (i) 
 Other pests some- 
 
 Other pests com- 
 
 
 
 
 pests (2) 
 
 times seen (i) 
 
 mon (o) 
 
 
 
 RATS 
 
 No rats in house 
 
 Rats infrequently 
 
 Much damage by 
 
 
 
 AND 
 
 or barn (6) 
 
 seen; little dam- 
 
 rats (o) 
 
 
 
 MICE 
 
 
 age done (i) 
 
 
 
 
 
 No mice in house 
 
 Mice infrequently 
 
 Much damage by 
 
 
 
 
 or barn (4) 
 
 seen ; little dam- 
 
 mice (o) 
 
 
 
 
 
 age done (i) 
 
 
 
 
 
 
 Dog and cat (i) 
 
 No dog or cat (o) 
 
 
 
 
 
 Traps or poisons 
 
 No traps or poi- 
 
 
 
 
 
 used (i) 
 
 sons used (o) 
 
 
 
 
 
 Concrete construc- 
 
 No concrete con- 
 
 
 
 
 
 tion (2) 
 
 struction or tin 
 
 
 
 
 
 
 to cover holes (o) 
 
 
 
 
 
 
 
 
 
 GRAND 
 
 roTAL 
 
 
 
 
 
 REFERENCE BOOKS 
 
 Broadhurst, Home and Community Hygiene, Chapter IX (For teachers). J. B. 
 
 Lippincott Company. 
 
 Caldwell and Eikenberry, General Science, Chapter XX. Ginn and Company. 
 Doane, Insects and Disease. Henry Holt and Company. 
 
 Headier, Effective Methods of Fly Control. Sci. Amer. Supplement, March 9, 1918. 
 Headier, The Mosquito Question. Scientific American Supplement, April 6, 1918. 
 Herrick, Insects Injurious to the Household. The Macmillan Company. 
 Hodge and Dawson, Civic Biology, Chapters X, XI, XIII, XVIII (Good). Ginn 
 
 and Company. 
 
 Hodge, Nature Study and Life. Ginn and Company. 
 Hunter, A Civic Biology, Chapter XV. American Book Company. 
 Hunter, Laboratory Problems in Civic Biology, Chapter XV. American Book 
 
 Company. 
 
 Kellogg, American Insects (For teachers). Henry Holt and Company. 
 Kellogg and Doane, Economic Zoology and Entomology, Chapters XXX, XXXI. 
 
 Henry Holt and Company. 
 
 Ritchie, Primer of Sanitation, Chapter XXIX. World Book Company. 
 Smith and Jewett, Introduction to the Study of Science, Chapter XII. The Macmillan 
 
 Company. 
 
CHAPTER IX 
 HOW WASTES ARE REMOVED FROM THE HOME 
 
 Problems. i. To understand how wastes are removed 
 from the body. 
 
 2. To understand the system of waste removal needed for 
 the home. 
 
 3. To learn how the various plumbing fixtures work. 
 
 4. To see how a septic tank does its work. 
 
 Experiments. i. To see how a siphon works. 
 2. To understand how a flush tank works. 
 
 Project I. To PREPARE MYSELF TO KEEP THE HOME PLUMBING 
 
 SYSTEM IN ORDER. 
 
 This involves a thorough study of the devices, piping, etc. in the 
 home. Diagrams should be made of pipe systems showing valves 
 and cut-offs, etc., and of individual devices, as traps, bowls, toilets, 
 flush tank, and faucets. 
 
 Study the devices seen at plumbers. Talk with men who know 
 how these devices work. Find out how to remedy a clogged sink drain, 
 toilet, and wash bowl drain. Learn what to do when pipes are frozen 
 and when a large leak occurs, and how to repair your faucets. Be 
 sure you know how to shut off water, gas, and electricity from the 
 entire house. 
 
 A collection of pictures of plumbing devices cut from magazines 
 and described in your own words will make a splendid section in your 
 final report of this project. 
 
 144 
 
HOW WASTES ARE REMOVED FROM THE BODY 145 
 
 How wastes are 
 removed from the 
 human body. We 
 have seen that the 
 human body uses 
 foods wherever work 
 is done in it. After 
 the food is digested 
 in the food tube it 
 is absorbed by the 
 blood which carries 
 it through a system 
 of pipes called veins 
 to a pumping station 
 called the heart. 
 This is a double 
 station ; the left side 
 of it forces the blood 
 
 The upper cavities in the heart are called auricles (right 
 or left), the lower, the ventricles (right or left). 
 Follow the arrows. In what respect is the heart 
 like a force pump ? 
 
 through the arteries (see diagram) to all parts of the body, 
 while the right side pumps blood to the lungs. Here, as 
 
 we have seen before, 
 
 1" 
 
 VCS5K, 
 
 I 
 
 jalf 
 
 LYMPH SP/teiFV 
 ^"'1 
 
 TUBB 
 
 The exchange between blood and the cells of the body. Called 
 H.-WHIT. CIV. SCI. IN THE HOME IO 
 
 it gives up carbon 
 dioxide, and receives 
 its burden of oxygen. 
 Before the blood 
 reaches the cells, the 
 little units of building 
 material of which the 
 body is composed, the 
 vessels containing it 
 divide into tiny tubes 
 capillaries. 
 
146 HOW WASTES ARE REMOVED FROM THE HOME 
 
 The liquid food soaks through the thin walls of the capil- 
 laries and bathes the cells so that they are continually 
 supplied with food. In the cells the food is oxidized and 
 energy is released. Some of the food containing nitrogen 
 is used to build tissue and repair the body. Nitrogen 
 does not unite easily with oxygen, and hence a consider- 
 able amount of nitrogenous material must be passed from 
 the body as waste. This nitrogenous waste, along with 
 other waste materials, is passed out from the cells into the 
 lymph spaces, then into the lymph tubes, and ultimately 
 gets into the blood again, this time being carried through 
 veins, which are tubes leading toward the heart. Wastes 
 containing nitrogen are finally collected by the kidneys, from 
 which organ they are passed out of the body in the urine. 
 Through the food tube, other wastes and material which 
 cannot be digested are passed out in a partly decayed con- 
 dition from the body. This work of decay is carried on by 
 means of millions of bacteria which live in the lower part of 
 the food tube. 
 
 Why we need a system to remove wastes from the home. 
 All body wastes from the home as well as garbage, used 
 water, and the like must be removed from our homes and 
 put where they cannot do any harm to others. Wastes from 
 the body contain bacteria, possibly some harmful ones. If 
 we were alone in the world we could afford to be selfish, but 
 when we are living where there are many other people, we 
 cannot do anything which might do harm to others. Open 
 privies to which flies can go might be the means of spreading 
 disease among one's own brothers and sisters. Garbage 
 thrown out and left to decay may mean millions of flies 
 for you and your neighbors. Water and wastes from "the 
 kitchen sink allowed to form a dirty, smelling pool outside 
 
THE NEED OF SANITARY PLUMBING 147 
 
 may become the breeding place of insects as well as a place 
 of foul odors. The purpose of this chapter is to point out 
 some of the means by which sewage is removed from the 
 home and rendered harmless to others. We must remember 
 that sewage or material containing wastes from the body 
 substances is very dangerous to health. It has been 
 shown many times that as a result of carelessness, germs 
 from sewage pass into the drinking water or get on the 
 food. It is necessary, therefore, that sewage everywhere, 
 in cities as well as the country, be properly disposed of 
 else it becomes a menace to health. In 1854 there was 
 a great outbreak of Asiatic cholera in London. Some parts 
 of the city were stricken much more than others. In those 
 clays people got their water from wells, and the Broad Street 
 pump had such a reputation for clean, sparkling water, 
 that people from blocks away went to it for their drinking 
 water. It was found, however, that one of the greatest 
 outbreaks of cholera was among people taking water from 
 this well, so the health authorities investigated the condi- 
 tions there. Imagine their horror to find the well water 
 separated by only a single layer of old worn-out bricks 
 from a cesspool which received the waste materials from 
 many cholera patients. As cholera is a disease of the in- 
 testines or bowels millions of germs were being placed in 
 that well water every day. After the well was closed to the 
 public, the epidemic subsided in that part of the city. This 
 is only one instance among many where germs in the water 
 supply have done untold harm. 
 
 The need of sanitary plumbing. In these days it is 
 hardly necessary for people to have outdoor insanitary 
 privies. If an outdoor privy is necessary, then all parts 
 should be carefully screened to prevent flies from getting 
 
148 HOW WASTES ARE REMOVED FROM THE HOME 
 
 in, and the lids of the seats should be close-fitting. Earth 
 mixed with lime should be used constantly to keep the waste 
 material in the receiving vault covered so that flies cannot 
 get to it. In most homes nowadays it is quite possible 
 to have indoor toilets and pass the waste material along 
 with the kitchen and other wastes into an underground 
 
 sewer in cities and 
 into cesspools or 
 septic tanks in the 
 country. 
 
 The modern bath- 
 room. Most houses 
 nowadays have a 
 warm indoor bath- 
 room, furnished with 
 all the fixtures shown 
 in the illustration ; a 
 washbasin, bathtub, 
 mirror, cupboard, 
 towel racks, stool, 
 and toilet. Not very 
 many years ago it 
 was thought proper 
 to cover all the 
 plumbing with 
 wood, but this is insanitary, because it makes an excellent 
 place for germs to lodge and grow. Now we find bath- 
 rooms furnished with one-piece sanitary bowls, and tubs 
 made either of porcelain or metal, everything raised from 
 the floor, with all parts easy to get at in case of repair. 
 A tub with cold water at least is an essential part of a bath- 
 room, and a shower bath if the water supply is sufficient, 
 
 A modern bathroom. 
 
THE MODERN BATHROOM 
 
 149 
 
 Snr\ /*' SETS 
 
 adds much pleasure to the daily life. A little knowledge of 
 a few scientific principles underlying the operation of these 
 fixtures will be useful for us to have and may save much ex- 
 pense and trouble. We have already studied different types 
 of faucets, and know how to make simple repairs on them. 
 
 Experiment. To see how the siphon works. 
 
 Materials: Battery jar. Glass beaker. Rubber tube. Glass tube. 
 
 Pulley with little friction. Cord or rope to go over the pulley. 
 Method: (A) Hang a short heavy cord or small rope over the easily 
 
 running pulley with the two ends at the same level. See figure (a). 
 
 Result ? Change the cord 
 
 so that one end hangs 6 
 
 inches or more lower than 
 
 the other side. See figure 
 
 (b). Result? (B) Con- 
 nect a six-inch length of 
 
 glass tubing to one end of 
 
 the rubber tube. Fill the 
 
 entire glass and rubber 
 
 tube with water. Hold 
 
 the finger over the end of 
 
 the glass and put the end 
 
 of the rubber tube into a 
 
 jar of water. Hold the 
 
 end of the glass tube just 
 
 below the level of the 
 
 water in the jar, and open 
 
 it. Carefully raise the 
 
 tube until the end is just 
 
 level with the water sur- 
 face in the jar. See figure (c). Does water run out? Does it run 
 
 back? Give reason. Lower the end of the glass tube so that it is 
 
 several inches below the level of the water in the jar to (d) in figure. 
 
 Result ? Explain. What will happen if it is raised above the level of 
 
 water in the jar? Try it. 
 Conclusion: The tube is used in this experiment as a siphon. Explain 
 
 how much of the action of the siphon depends on the pressure of the 
 
 atmosphere. How does the analogy with the rope help to explain a 
 
 part of the action of the siphon ? 
 
150 HOW WASTES ARE REMOVED FROM THE HOME 
 
 A flush tank. If you will examine the diagram accom- 
 panying this paragraph carefully, you will find that water 
 gets into the tank through the action of the ball float, 
 which, when the toilet is flushed, opens a valve and allows 
 a new supply of water to come into the tank. When the 
 water reaches a certain level the float automatically closes 
 the valve. The toilet itself is flushed by pulling a lever 
 
 The bathroom flush tank. 
 
 which opens the valve at the base of the siphon. As the 
 water begins to flow this valve closes, and the water in the 
 pipe leading to the toilet acts as the plunger of a piston (see 
 diagram) , and water is passed into the flush pipe through 
 the siphon. As soon as the water in the tank is lowered 
 to the point D the siphon tube fills with air and the action 
 stops. The tank then fills up as has been shown pre- 
 viously. 
 
 The study of your own home flush tank makes an inter- 
 esting experiment. 
 
THE HOME SYSTEM OF DRAIN PIPES 
 
 Experiment. To understand how the flush tank works. 
 
 Remove the cover from the flush tank. (A) Pull the lever to allow the 
 water to run out. Locate the inlet valve. Where is it? What con- 
 trols it ? Make a diagram to show clearly how the water inlet is con- 
 trolled. (B) Hold the ball-float valve to prevent more water entering 
 the tank. Pull the lever to empty the tank. Notice whether the tank 
 is emptied by use of a siphon or whether there is a rubber ball valve. 
 If it has a ball valve, fill with water again and empty. Observe just 
 when the ball closes the valve. Can you explain why the valve stays 
 open just so long? Make one or more diagrams to show the empty- 
 ing mechanism. How would you make repairs if the rubber valve 
 leaked? What would you do if the ball float were broken off? 
 
 The home system of drain pipes. In order to get water 
 and wastes out of the house it is necessary to have a system 
 of drain pipes consisting 
 of a large soil pipe from 
 cellar to roof. All the 
 sinks, toilets, and tubs 
 must connect with this 
 soil pipe. It is neces- 
 sary, then, to arrange our 
 house so as to have all 
 of the fixtures grouped 
 about this drain pipe. 
 The pipe must leave the 
 house at a point slightly 
 lower than at any other 
 place, and all pipes leav- 
 ing fixtures must also 
 run slightly down hill. 
 The large and straight 
 
 pipes are usually iron with the joints tightly closed 
 by means of cement substances, while the smaller pipes 
 are usually lead. In order to prevent odors from de- 
 
 An S-trap showing water seal and vent. 
 
152 HOW WASTES ARE REMOVED FROM THE HOME 
 
 caying substances or sewer gas from getting into the 
 house, fixtures known as traps are necessary. A study 
 of the figure on page 151 shows that the trap is an inverted 
 siphon, and forms a water seal which prevents any gas 
 from going by the water. A good example of such a water 
 seal is seen in the refrigerator trap, where the water seal 
 is used to prevent warm air from getting in to melt the ice. 
 
 Why well water is sometimes unsafe. 
 
 In the water seal or traps in our houses, the vent (see fig- 
 ure) is usually necessary to keep the air pressure equal 
 on each side of the trap, so that the water will not be all 
 sucked out, thus leaving no protection against odors. 
 
 Under the kitchen sink we often find a grease trap. This 
 is fitted, as are all other traps, with a cap which is easily 
 accessible, and which can be unscrewed to remove the 
 grease which otherwise might clog the drain pipes. 
 
 Disposal of sewage. Where there is no city sewage 
 system the disposal of sewage is a most important ques- 
 
THE SEPTIC TANK 153 
 
 tion. In homes where no proper provision is made, we 
 frequently find sewage running into open drains, or even 
 upon the soil, there becoming a dangerous menace to 
 health. Most country homes nowadays have a cesspool. 
 This is nothing more or less than a deep hole dug in the 
 earth, having an open bottom, uncemented rock or brick 
 walls and a covered top. It is situated a few feet away 
 from the house, and receives all the sewage which drains 
 out gradually through holes at the sides and bottom into 
 the surrounding soil. If a great deal of water is used, the 
 cesspool is too small, and satisfactory drainage is impos- 
 sible. Moreover, unless great care is taken, there is dan- 
 ger of drainage into a near-by well. In clayey soils, cess- 
 pools give much trouble, as little drainage takes place, and 
 frequent pumping out is necessary. A cesspool should be 
 simply a temporary means of getting rid of sewage. 
 
 The septic tank. By far the most modern and hygienic 
 method of sewage disposal is by means of what is known 
 as the septic tank. It has been discovered that? there are 
 two types of bacteria, one of which (anaerobic) thrives 
 without air, releasing oxygen from the substances on which 
 it feeds, and another (aerobic) that must have air. The 
 septic tank is made with at least two compartments, both of 
 which are made of cement and are water-tight. In the first 
 compartment sewage from the house flows, and is there 
 attacked by the anaerobic bacteria, which cause the solid 
 matter to become liquid. Fats and other substances rise 
 to the surface, forming an almost air-tight scum, which 
 assists the anaerobic bacteria to do their work more effec- 
 tively. As the sewage is decomposed it passes into the 
 second tank in an almost colorless and odorless condition. 
 When this tank fills its contents are siphoned off into 
 
154 HOW WASTES ARK KKMOVEI) I ROM THE HOME 
 
 drains under the surface of the ground. This sewage is 
 now quite harmless, as all organic contents have been 
 
 A septic tank. 
 
 decomposed or oxidized by the bacteria, so that no harm 
 can come from it. Several different types of septic tanks 
 are now on the market, and they are infinitely better than 
 the old type of cesspool. The liquid leaving the septic 
 tank contains much valuable fertilizing material, and is 
 generally used on the home garden. 
 
 Sanitary garbage pails and their care. We have already 
 learned that flies feed and lay their eggs in garbage. The 
 garbage pail should be of metal so that it can easily be scalded 
 and should have a tight-fitting cover. During the summer 
 it should be emptied every day or two, as otherwise the 
 bacteria of decay will cause the refuse contained in it to 
 smell badly. If the garbage is not taken up by a collector 
 it ought to be either burned or buried so deep that the 
 flies cannot get at it. If we live on a farm all the fresh 
 garbage should be fed to the , pigs or chickens daily. The 
 pail should be kept covered in an inconspicuous place and, 
 as every good housewife knows, should be sterilized with 
 
USE OF THE SCORE CARD 
 
 155 
 
 boiling water and washing soda at least twice a week 
 during the hot weather. If these rules are observed we 
 shall have no trouble from the garbage pail during hot 
 weather. 
 
 Use of the score card. Here again the city boy and 
 g'rl have an advantage over his or her country cousin. 
 This means more care and an honest attempt to improve 
 conditions on the part of those whose environment is not 
 so favorable. And we must also remember that city condi- 
 tions are sometimes much worse than country conditions 
 because of lack of repair of fixtures or carelessness on the 
 part of users. So both city and country dwellers may have 
 to make low scores. Remember that, after all, improve- 
 ment is the big thing. 
 
 SCORE CARD. REMOVAL OF WASTES FROM MY HOME 
 
 
 
 
 
 MY SCORE 
 
 
 EXCELLENT 
 
 FAIR 
 
 VERY POOR 
 
 
 
 
 
 
 
 TOTAL 
 
 SYSTEM 
 OF 
 
 Exposed plumbing 
 throughout (2) 
 
 Exposed plumbing 
 in bathroom and 
 
 No exposed plumb- 
 ing (o) 
 
 
 
 PLUMB- 
 
 
 sink (i) 
 
 
 
 
 ING 
 
 All parts of system 
 having traps (toi- 
 
 Traps at toilet and 
 sink (i) 
 
 No traps (o) 
 
 
 
 
 let, bowl, bath- 
 
 
 
 
 
 
 tub, sink, tubs) 
 
 
 
 
 
 
 (2) f 
 
 
 
 
 
 
 All pipes laid at 
 
 
 Not all pipes at 
 
 
 
 
 slight grade (2) 
 Ventilation ducts 
 
 Ventilation ducts 
 
 grade (o) 
 No ventilation 
 
 
 
 
 provided (2) 
 
 not always pro- 
 
 ducts (o) 
 
 
 
 
 
 vided (i) 
 
 
 
 
 
 Trap at house exit 
 
 
 No trap at house 
 
 
 
 
 (2) 
 
 
 exit (o) 
 
 
 
 TOILET 
 AND 
 
 All porcelain or 
 enameled fix- 
 
 Porcelain or enam- 
 eled fixtures, 
 
 No porcelain or 
 enameled fix- 
 
 
 
 BATH- 
 
 tures, including 
 
 wooden seat (2) 
 
 tures (o) 
 
 
 
 ROOM 
 
 toilet seat (3) 
 
 
 
 . 
 
 
 FIXTURES 
 
 Bathtub, foot tub, 
 
 Bathtub, no show- 
 
 No bathtub (o) 
 
 
 
 
 and shower (2) 
 
 er or foot tub (i) 
 
 
 .... 
 
 
 
 More than one 
 
 One bathroom (2) 
 
 No bathroom (o) 
 
 
 
 
 bathroom (2) 
 
 
 
 
 
 
 Lavatory and toilet 
 
 Lavatory only on 
 
 No lavatory (o) 
 
 
 
 
 on ground floor 
 
 ground floor (i) 
 
 
 
 
 
 (3) 
 
 
 
 .... 
 
 
156 HOW WASTES ARE REMOVED FROM THE HOME 
 
 SCORE CARD. 
 
 REMOVAL OF WASTES FROM MY HOME 
 
 Continued 
 
 
 
 
 
 MY S 
 
 CORE 
 
 
 EXCELLENT 
 
 FAIR 
 
 VERY POOR 
 
 
 
 
 
 
 
 
 TOTAL 
 
 KNOWL- 
 
 Sufficient knowl- 
 
 Knowledge which 
 
 No knowledge of 
 
 
 
 EDGE 
 
 edge of system to 
 
 will give sufficient 
 
 system. Must 
 
 
 
 OF 
 
 
 information t o 
 
 call plumber and 
 
 
 
 SYSTEM 
 
 
 call plumber to 
 
 let him find out 
 
 
 
 
 (a) Clean out 
 
 (a) Clean out 
 
 the trouble (o) 
 
 
 
 
 trap (3) 
 (b) Clean out 
 
 trap d) 
 (b) Clean out 
 
 
 .... 
 
 
 
 grease trap (3) 
 (c) Repair flush 
 
 grease trap (i) 
 (c) Fix flush 
 
 
 
 
 
 tank float (4) 
 
 tank float (i) 
 
 
 
 
 
 SEWAGE 
 
 Sewage connection 
 
 Cesspool (5) 
 
 Sewage flows un- 
 
 
 
 CONNEC- 
 
 with town or city 
 
 
 treated into open 
 
 
 
 TION 
 
 system (10) 
 
 
 drains (o) 
 
 
 
 
 Septic tank, prop- 
 
 Septic tank occa- 
 
 
 
 
 
 erly working (10) 
 
 sionally giving 
 
 
 
 
 
 
 trouble (5) 
 
 
 
 
 
 (Score only one of 
 
 Outdoor privies if 
 screened and dis- 
 
 Outdoor privies not 
 screened or disin- 
 
 
 
 
 above.) 
 
 infectant used 
 
 fected (o) 
 
 
 
 
 
 every day (4) 
 
 
 
 
 
 
 
 
 
 
 CARE OF 
 
 Garbage 
 
 Garbage 
 
 No garbage collec- 
 
 
 
 GARBAGE 
 
 (a) Collected by 
 
 (a) Collected by 
 
 tion (o) 
 
 
 
 AND 
 GARBAGE 
 
 city daily 
 (b) burned daily 
 
 city once a week 
 (b) burned once a 
 
 Garbage burned ev- 
 ery two weeks (o) 
 
 
 
 PAIL 
 
 
 week 
 
 Garbage scattered 
 
 
 
 
 (c) buried at least 
 
 (c) buried six 
 
 over garden in 
 
 
 
 
 2 ft. under sur- 
 
 inches under 
 
 summer (o) 
 
 
 
 
 face daily 
 
 surface 
 
 
 
 
 
 (d) fed to pigs 
 
 (d) fed to pigs or 
 
 
 
 
 
 and chickens one 
 
 chickens once a 
 
 
 
 
 
 day after collec- 
 
 week (any meth- 
 
 
 
 
 
 tion (any meth- 
 
 od) (ij) 
 
 
 
 
 
 od) (3) 
 
 
 
 
 
 
 Metal pail with 
 
 Metal pail, loose 
 
 Wooden pail, no 
 
 
 
 
 tight cover (2) 
 
 cover (i) 
 
 cover (o) 
 
 
 
 
 Pail emptied daily 
 in summer (2) 
 
 Pail emptied week- 
 ly d) 
 
 Pail not emptied 
 of tener than once 
 
 
 
 
 
 
 every two weeks 
 
 
 
 
 Pail sterilized twice 
 
 Pail sterilized 
 
 (o) 
 Pail not sterilized 
 
 
 
 
 a week in sum- 
 
 weekly (i) 
 
 more often than 
 
 
 
 
 mer (2) 
 
 
 once every two 
 
 
 
 
 
 
 weeks (o) 
 
 
 
 
 Pail kept in incon- 
 
 Pail with some odor 
 
 Bad odor from gar- 
 
 
 
 
 spicuous place 
 
 (i) 
 
 bage (o) 
 
 
 
 
 no odors (i) 
 
 
 
 
 
 
 
 
 
 
 
 GRAND 
 
 TOTAL 
 
 
 
 
 
REFERENCE BOOKS 157 
 
 REFERENCE BOOKS 
 
 Broadhurst, Home and Community Hygiene, Chapter VII (Teacher's use). J. B. 
 
 Lippincott Company. 
 
 Butler, Household Physics, pages 356-364. Whitcomb and Barrows. 
 Caldwell and Eikenberry, General Science, Chapter XIV. Ginn and Company. 
 Chapin, Sources and Modes of Infection (Advanced and teacher's use). John 
 
 Wiley and Sons. 
 
 Hunter, A Civic Biology, Chapters XXII, XXIV. American Book Company. 
 Lynde, Physics of the Household, Chapter VII. The Macmillan Company. 
 Winslow, Healthy Living, Chapter XII. Charles E. Merrill Company. 
 
CHAPTER X 
 
 GERM DANGERS AND HEALTH HABITS 
 
 Problems. i. To understand the relation of bacteria 
 to disease. 
 
 2. To discover the defenses of our body against germs. 
 
 3. To see how habits control our health. 
 
 4. To learn good health habits. 
 
 Experiments. i. To 
 show how infection takes 
 place. 
 
 2. To make a hygienic 
 drinking cup. 
 
 Project I. To COM- 
 PARE MY DAILY USE OF 
 TIME WITH AN IDEAL 
 PLAN. 
 
 i. Make two circles 
 with diameters of 3! 
 inches. Just inside the 
 circles put in two series 
 of figures, i to 12, 
 equally spaced to rep- 
 resent the twenty-four 
 hours of the day. (See 
 diagram.) 
 
 2. In one of these mark out the spaces representing time given to 
 various things suggested as ideal. 
 
 158 
 
 Tlicliviglvt 
 
 This is one pupil's daily program for five days a 
 week. 
 
WHAT BACTERIA LOOK LIKE 
 
 3. Keep a record of your own habits in these matters for one week. 
 Average these, and on the basis of the averages fill out the second 
 circle to represent your own daily schedule. 
 
 Project II. To FORM CORRECT HEALTH HABITS. 
 
 Join the " Health Crusaders." Perform their assigned tasks 
 regularly and make proper records. Keep a monthly record as sug- 
 gested by the following table. 
 
 PHYSICAL EXAMINATION 
 
 MONTHLY RECORD 
 
 1 
 
 2 
 
 3 
 
 4 
 
 5 
 
 6 
 
 7 
 
 8 
 
 9 
 
 10 
 
 i. Weight . ,. 
 
 
 
 
 
 
 
 
 
 
 
 2. Height . . 
 
 
 
 
 
 
 
 
 
 
 
 3. Chest measure 
 
 
 
 
 
 
 
 
 
 
 
 (i) Inflated . 
 
 
 
 
 
 
 
 
 
 
 
 (a) Deflated . 
 
 
 
 
 
 
 
 
 
 
 
 (3) Chest ex- 
 
 
 
 
 
 
 
 
 
 
 
 pansion = 
 
 
 
 
 
 
 
 
 
 
 
 4. Lung capac- 
 
 
 
 
 
 
 
 
 
 
 
 ity .... 
 
 
 
 
 
 
 
 
 
 
 
 5. Time can 
 
 
 
 
 
 
 
 
 
 
 
 hold breath 
 
 
 
 
 
 
 
 
 
 
 
 6. Eye test . . 
 
 
 
 
 
 
 
 
 
 
 
 7. Hearing . . 
 
 
 
 
 
 
 
 
 
 
 
 8. Grip test . . 
 
 
 
 
 
 
 
 
 
 
 
 9. Lifting 
 
 
 
 
 
 
 
 
 
 
 
 strength . . . 
 
 
 
 
 
 
 
 
 
 
 
 10. Age . . . 
 
 
 
 
 
 
 
 
 
 
 
 Where germs live and how they grow. Some one has 
 said that bacteria exist " anywhere but not everywhere." 
 They swarm in soils, in impure water, in stale milk, in the 
 dead bodies of plants and animals, and to a certain extent 
 in living bodies as well. They cause decay, and so far as we 
 know, all " catching " diseases. We could tell many other 
 things they do, and we have already seen some of them. 
 
 What bacteria look like. It is easy to see the effect 
 of bacteria on milk when it sours and on food when it 
 decays, or to observe colonies of them growing in a Petri 
 
160 GERM DANGERS AND HEALTH HABITS 
 
 dish, yet each bacterium is so small that it is visible only 
 under a very high power microscope. Bacteria are single- 
 celled plants, unable to make their own food, and con- 
 
 Types of bacteria, i. Rods. 2. Spheres. 3. Spirals. 
 
 sequently do much harm by living at the expense of 
 other things, as upon dead organic material. Some one has 
 said that in order to recall their forms one must think of 
 a billiard cue, a billiard ball, and a corkscrew. A glance 
 at the illustration will show how true this statement is. 
 They are rodlike (called bacillus), ball-like (called coccus), 
 or spiral (named spirillum) in form. Many kinds can 
 move with great speed through the water by means of 
 tiny threadlike structures which vibrate rapidly. They 
 never thrive except in moisture, although 
 some of them may be dried and float 
 around in the air some time without dy- 
 ing, becoming active again when moist. 
 Many forms endure an unfavorable en- 
 vironment of heat and cold as well as 
 dryness by forming a thick resistant 
 coat about their body. In this condi- 
 tion they are called spores. 
 
 How germs cause disease. It has been estimated 
 that over fifty per cent of the people who die each year are 
 
 Bacteria forming spores. 
 
METHODS OF INFECTION 161 
 
 killed by bacteria. A very large portion of the infectious 
 diseases might be prevented if people knew more about 
 the ways by which germs enter the body and were more 
 careful to keep them out. It may help us to see how 
 germs get into the body if we study the way in which an 
 apple is protected against infection and by what means it 
 is infected. 
 
 Experiment. To show how infection takes place. 
 
 Materials: A sound apple. A decaying apple. Toothpicks. 
 
 Method: (a) Make a small irregular hole through the skin of the sound 
 apple. Fill this with decaying pulp from the other apple, (b) Stick 
 a toothpick into the rot of the decaying apple and then stick it into 
 the sound apple, leaving it there, (c) Sterilize a toothpick by pass- 
 ing one end of it through a flame several times without allowing it to 
 take fire. Stick this end of the toothpick into the apple and leave it. 
 (d) In a four-inch area on the unbroken and unbruised skin of the 
 sound apple lay a little of the decaying apple pulp. Set the apple 
 away in a dark, warm place. 
 
 Observation and Conclusion: Examine the apple daily until changes have 
 occurred in one or more of the places. Where does infection occur? 
 Explain what natural defense against infection the apple has, but how 
 conditions may arise in which decay results. 
 
 Methods of infection. When we take germ diseases 
 the germs enter our bodies by means of the nose, mouth, 
 through body openings, or through a break in the skin. 
 They may be carried by means, of food, water, or even 
 through the air, and the germs usually are taken directly 
 from a person who has the disease. The most common 
 method of spreading disease is by sneezing or coughing, or 
 even breathing and talking close to the face of some one 
 else. If you have ever watched a person talk when in the 
 sunshine, you may have observed a constant spray of tiny 
 droplets which are forced out from the mouth. These 
 droplets are sprayed from two to three feet from the 
 
 H.-WHIT. CIV. SCI. IN THE HOME II 
 
162 
 
 GERM DANGERS AND HEALTH HABITS 
 
 mouth of the person. Most children's " catching " diseases 
 begin with sore throat, sneezing, and coughing. Measles, 
 whooping cough, scarlet fever, tonsillitis, influenza, and 
 diphtheria all begin in this way, hence it is very easy for 
 any one unthink- 
 ingly to spray out 
 the germs when 
 coughing, sneezing, 
 or even talking, and 
 
 10J 
 
 t. 
 
 A common method of spreading germs. (After 
 Winslow.) 
 
 thus to infect some 
 one else. A good 
 health habit to form 
 very early in life is 
 that of the proper 
 use of the handkerchief. Never cough or sneeze into 
 the open air, but into a handkerchief. Keep the nose 
 well blown to prevent an unpleasant appearance as well 
 as possible spread of colds. A " common cold " soon 
 becomes everybody's cold in a schoolroom in which the 
 children do not have the proper health habits. A good 
 rule to observe with reference to colds is this: remain 
 quietly at home resting in bed, for thus one will not only 
 prevent others from " catching " it, but by rest and proper 
 food it will soon be cured. 
 
 Disinfectants and how to use them. Sometimes it 
 becomes necessary in our homes to destroy the bacteria 
 which cause disease. This is done by the use of disinfect- 
 ants. Many different substances which have a deadly 
 action on bacteria can be obtained at the drug store. 
 Inasmuch as these substances, such as carbolic acid, lysol, 
 bichloride of mercury, and formaldehyde, are deadly poisons, 
 we must exercise the greatest care in their use. For disin- 
 
AIR AND HEALTH 163 
 
 fecting wounds or cuts iodine is much used ; while for use 
 on hands, a weak (i to 25 parts water) solution of carbolic 
 acid followed by scrubbing with green soap is safe and sure. 
 
 Our body defenses against disease. Germ diseases 
 are usually caused by poisonous toxins. These are waste 
 materials given off by bacteria which act upon the individ- 
 ual like snake venom. Some people are very much more 
 resistant to these toxins than others, and therefore are less 
 likely to take " catching diseases." This resistance to or 
 defense against disease, when powerful enough to kill the 
 germs or offset the harm from toxins, produces an immu- 
 nity. Immunity may be natural, or it may be acquired in 
 the case of some diseases. This, for example, is done in 
 the case of diphtheria by means of antitoxin treatment, 
 and in the case of small pox and typhoid, by means of 
 vaccination. The theories underlying immunity will be 
 discussed more fully in the next book. Natural immunity, 
 however, may be increased by keeping the body in just 
 as good condition as possible. Proper habits of health as 
 suggested in the following paragraphs will assist greatly 
 in maintaining one's health. 
 
 Air and health. We have already referred to the need 
 of oxygen. It is generally agreed at the present time that 
 we must have as much fresh air as possible, that our rooms 
 must be well ventilated, that porous clothes must be worn 
 so that the body can have a constant air bath, for the skin 
 under the clothes needs air as well as the parts exposed. 
 We have come to depend upon outdoor play and outdoor 
 sleeping as means of good health. We should always 
 practice good posture and acquire good breathing habits. 
 An excellent habit is that of morning exercise with the win- 
 dows thrown open. Remember that the lungs need exercise 
 
164 GERM DANGERS AND HEALTH HABITS 
 
 Simple foods are nourishing. 
 
 Indigestible foods. 
 
 Bulky foods. (Eastman Kodak Co.) 
 
CARE OF THE TEETH 
 
 165 
 
 and air, and that only by deep breathing which expels 
 much of the stagnant air which accumulates in the lungs 
 can we make them resistant against disease germs. 
 
 Food and health. Boys and girls should eat enough, 
 but not too much. They should not eat when very tired, 
 and should eat only a light meal at night. Hard and bulky 
 foods should be included in the menu, since they tend to 
 prevent constipation. Raw foods containing vitamines 
 should always be a part of the diet, especially uncooked 
 milk, fresh fruits, and fresh vegetables, but all raw 
 foods should be carefully washed because of danger from 
 germs. 
 
 Care of the teeth. Thorough chewing of the food is 
 necessary for good health. Many of us bolt our food, and 
 as a result suffer from indigestion. The teeth are important 
 factors in the habit of proper chewing. We can form no 
 better habit than that of properly brushing them. The 
 teeth should be brushed at least twice a day, and not only 
 the teeth but also the gums around them. Brushing up 
 
 L" 
 
 Results of neglect and care of teeth. 
 
 and down rather than across the teeth is of much more 
 value, because it dislodges the food particles held between 
 the teeth, and thus prevents their decay. The teeth should 
 be examined by a dentist at least twice a year, for this will 
 save much pain and possible loss later on. Decay of the 
 
i66 GERM DANGERS AND HEALTH HABITS 
 
 teeth comes as a result of bacteria lodging in the same 
 crevices with food. They pour out an acid waste sub- 
 stance which attacks the hard enamel of the teeth, breaking 
 it down and thus allowing germs gradually to attack the 
 living portion of the teeth underneath. Upon our teeth 
 depends much of our health later on in life, so let us form 
 habits of proper care of them while we are young. 
 
 Body poisons and good health. One of the best habits 
 to get early in life is that of regularity of bowel movement 
 for thus we may be spared the evils which come through 
 constipation. As we have studied before, the lower part of 
 the food tube, if not emptied regularly, becomes rilled with 
 decaying material, for this part of the food tube is always 
 
 alive with millions of 
 bacteria, which cause 
 decay. As this decay 
 takes place, the soluble 
 poisons set free are 
 easily passed through 
 
 the Wal1 f the 
 
 Drink si* glasses of water a day. 
 
 and get into the blood, 
 
 causing headache and a feeling of discomfort which often 
 attends constipation. Excellent suggestions which will help 
 us to fight this evil are the following. Drink a glass of water 
 when you get up in the morning, and at least one glass before 
 each meal. Take plenty of raw or cooked fruits except 
 bananas, blackberries, and raspberries. Green vegetables, 
 whole wheat bread, bran muffins, fats,- and oils are helpful 
 in keeping the bowels regular. Avoidance of tea and coffee, 
 and proper hours of sleep, all help in fighting this evil. 
 
 Get the habit of using your own cup when you drink. 
 Every one should know how to make his own drinking cup. 
 
EXERCISE AND HEALTH 
 
 167 
 
 Follow the directions given in the accompanying diagram, 
 and see if you can make yours. 
 
 A 
 
 square 
 piece 
 
 & 
 paper 
 
 Fold 
 A on ts B 
 
 along the line 
 D C. 
 
 F en the line A C 
 
 the line 
 
 F. and 
 
 scnitarcj 
 CUP 
 
 (After Tolman.) 
 Experiment. To make a hygienic drinking cup. 
 
 Materials: A sheet of strong clean paper six to eight inches square. 
 Method: Fold as suggested in the accompanying diagram. 
 
 Exercise and health. Most boys and girls may exer- 
 cise enough, but not properly. Especially in the case of 
 girls, proper posture, or poise of the body, in walking, sitting, 
 
i68 
 
 GERM DANGERS AND HEALTH HABITS 
 
 and standing, is necessary. The bad habit of sprawling over 
 the desk or table when at work makes for round-shouldered, 
 small-chested men and women. Learn to set the shoulders 
 square and back, keep the chest high and out, and both the 
 stomach and chin in. Military training, such as our young 
 men have had in the great World War, has done much to 
 increase their bodily resistance to disease, and to make 
 strong men of weaklings. 
 
 HOME DUTIES OF CHILDREN 
 
 MY OWN RECORD 
 
 TIME. MIN- 
 UTES PER 
 DAY 
 
 SCORE 
 
 i. Sweeping and dusting generalrooms 
 2. Full charge of own chamber 
 3. Making beds 
 4. Helping cook ... 
 
 
 
 5 Ironing 
 
 
 
 
 
 
 
 
 
 8. Taking care of furnace 
 9. Taking care of hens and chickens 
 10 Tending baby 
 
 
 
 11. Taking care of a pet : dog, cat, bird, fish, or rabbit 
 12 Taking care of garden and lawn 
 
 
 
 
 
 
 14 Setting tables 
 
 
 
 15 Washing dishes running errands 
 
 
 
 16. Other work 
 
 
 
 TOTAL .... 
 
 
 
 
 
 
 Copy this form of record in notebook. 
 
 Register average time per day given to work here listed. 
 
 A total of ip points for every 15 minutes devoted to any duty daily. 
 
 Boys and girls will score extra work not mentioned here under 16. No score 
 allowed over 100. Two and one half hours daily home work outside of school 
 work entitles you to a perfect score. 
 
 Home duties. Every boy and girl ought to have a 
 part in the duties as well as the pleasures of the home. 
 It is unfair to mother and father to have them assume all 
 the care of the house, and it ought to be part of your 
 
HABITS OF CLEANLINESS 169 
 
 training to have a practical knowledge of how the house 
 is made to run smoothly. Besides this, there is a certain 
 amount of healthful exercise in weeding the garden or 
 cleaning the walk or bringing up the coal or running a 
 sewing machine or a churn. The score card on page 168 
 will give you some idea of how well you are living up to 
 your part of the home duties. 
 
 Rest and health. Our days should be made up of work 
 and play, rest and sleep. It is just as bad to over-exer- 
 cise-, as it is to under-exercise. One should remember 
 that all machines need rest, and the human machine is 
 no exception to the rule. At least eight 
 hours of sleep should be had by every 
 boy and girl of high school age, and 
 nine or ten hours of sleep by younger 
 children. Fewer movies and more quiet 
 reading at home would be good for every 
 boy and girl. Moderation in all things is 
 a good rule. Overstrain of any kind 
 brings on fatigue, and in the end shows 
 
 . .-, Time for sleep. 
 
 that we cannot strain an organ without 
 paying for it. If we overstrain the eyes, for example, we 
 pay for it by wearing glasses later. If we overstrain in 
 athletics, we may have to give up athletics altogether. 
 Over-fatigue by keeping too late hours will surely call us to 
 account later in life. Let us learn while young the value 
 of complete relaxation, and let us, while we are growing, 
 get the habit of going to bed at the proper hour. 
 
 Habits of cleanliness. " Cleanliness is next to god- 
 liness " is an old saying, and a good one. Habits of clean- 
 liness at meals are particularly necessary. One should 
 always wash the hands after going to the toilet. Bathing 
 
170 
 
 GERM DANGERS AND HEALTH HABITS 
 
 the entire body at least once a week should be a habit, and 
 if the feet or body become covered with perspiration in 
 warm weather, one should bathe more frequently. 
 
 Always wash the hands before eating. (Eastman Kodak Co.) 
 
 Not only should we get the habit of cleanliness of body, 
 but we should also early in life strive for habits of cleanli- 
 ness of mind. We should learn to keep watch upon our 
 thoughts as well as upon our bodies, for purity of mind as 
 well as purity of body will have an effect on health as well 
 as an influence over others. 
 
 The use and abuse of drugs. One degrading habit to 
 which Americans are addicted is the use of patent medicines 
 and drugs. . American newspapers annually receive fully 
 $40,000,000 for advertising patent medicines; how much 
 more must the manufacturers of these medicines receive ? 
 It should be a rule never to use a patent medicine unless 
 it is prescribed by our physician. The body is a delicate 
 
THE USE AND ABUSE OF DRUGS 171 
 
 machine, and easily put out of running condition. If it is 
 out of order a physician should be consulted, and one 
 should not try to " doctor " himself. Boys and girls 
 should not drink tea and coffee. Cocoa and milk are bet- 
 ter beverages, as they are food substances; while neither 
 tea nor coffee have any food value, and are dangerous for 
 young people because they are apt to make them form the 
 habit of drinking tea and coffee to excess. It goes with- 
 out saying that alcohol in any form should not be used. 
 Tobacco has been proved to have a bad effect upon grow- 
 ing boys. Dr. Seaver of the physical training department 
 of Yale College some years ago made a careful comparison 
 of the growth of smokers and non-smokers during their 
 four years in college. He found that students who did not 
 
 Alcoholic drink, tea, coffee, and tobacco are especially harmful during the years of 
 
 bodily growth. 
 
 use tobacco gained ten per cent more in weight, twenty- 
 four per cent more in height, twenty-seven per cent more 
 in chest expansion, and seventy-seven per cent more in lung 
 capacity than did the smokers. The tobacco heart of 
 
172 GERM DANGERS AND HEALTH HABITS 
 
 smokers is well known to the athlete, and no boy who is in 
 training can have any doubt that the use of tobacco has a 
 definite effect on his " wind " when he trains for some 
 athletic contest. 
 
 Fifteen health rules. One of the most interesting and 
 helpful books written in late years is the manual, How 
 to Live, by Professor Irving Fisher and Dr. E. L. Fisk. 
 They summarize the health habits given in this chapter 
 in the following fifteen rules : 
 
 I. AIR: 
 
 1. Ventilate every room you occupy. 
 
 2. Wear light, loose, and porous clothes. 
 
 3. Seek out-of-door occupations and recreations. 
 
 4. Sleep out of doors, if you can. 
 
 5. Breathe deeply. 
 
 II. FOOD: 
 
 6. Avoid overeating. 
 
 7. Eat sparingly of meats and eggs. 
 
 8. Eat some hard, some bulky, some raw foods. 
 
 9. Eat slowly. 
 
 III. POISONS: 
 
 10. Move the bowels regularly and frequently. 
 
 11. Stand, sit, "and .walk erect. 
 
 12. Do not allow poisons and infections to enter the body. 
 
 13. Keep the teeth, gums, and tongue clean. 
 
 IV. ACTIVITY: 
 
 14. Work, play, rest, and sleep in moderation. 
 
 15. Keep happy. 
 
 Welfare pamphlets. Much help in forming good health 
 may be obtained from the welfare pamphlets such as those 
 issued by the Metropolitan Life Insurance Company and 
 the International Harvester Company. Several of the il- 
 lustrations in this chapter were taken from "Good Health 
 
HOW TO SCORE MY HEALTH HABITS 
 
 173 
 
 and How to Keep It," issued by the Eastman Kodak 
 Company for the benefit of its employees. 
 
 How to score my health habits. Everyday life is 
 nothing but repetition of things over and over again. 
 And that means our everyday life becomes habitual. One 
 great thinker and teacher has said that we are " bun- 
 dles of habits." Certainly our daily routine ought to be 
 largely a matter of habit and of good habits. Therefore 
 we should take no score whatever unless each point men- 
 tioned has become a matter of habit. There ought to be 
 a good many points that you can add to this score card, 
 some of which may be of more importance than the ones on 
 the card. Be sure to add these and bring them to class 
 for discussion. Perhaps by all working together you can 
 make an ideal card, much better than the one which 
 follows. 
 
 SCORE CARD. PERSONAL HEALTH HABITS 
 
 PERFECT 
 SCORE 
 
 MY SCORE 
 
 Regular daily routine 5 
 
 Setting-up drill and deep breathing 5 
 
 Cool rub or shower 5 
 
 Teeth brushed morning and. night f - ,". . . t . . . 5 
 
 Slow eating at meals 5 
 
 Food chewed well ...;,. 5 
 
 No overeating .... . "." . . .. ' ; . . . . 5 
 
 Cheerfulness at meals ..-..... 5 
 
 Regular toilet habits 5 
 
 Wash hands often, always after toilet 5 
 
 Clean shoes and clean linen 5 
 
 Loose, comfortable clothing 5 
 
 Feet warm and dry 5 
 
 Regular play hours 5 
 
 Exercise in open air two hours a day 5 
 
 Regular work and study hours (at least two hours) . . 5 
 
 Proper lighting for study 5 
 
 Bed before 10 P.M 5 
 
 Sleep in open air or with windows open top and bottom 5 
 
 No coffee, tea, or cigarettes 5 
 
 TOTAL 100 
 
174 GERM DANGERS AND HEALTH HABITS 
 SCORE CARD. PROTECTION AGAINST DISEASE 
 
 
 PERFECT 
 SCORE 
 
 MY SCORE 
 
 Vaccinated for smallpox 
 Teeth examined twice a year 
 All cavities filled 
 
 5 
 5 
 
 
 Eyes examined once a year 
 Glasses used when necessary 
 Keep more than five feet distant from those who 
 cough or sneeze 
 
 5 
 5 
 
 
 Take care to use handkerchief if you cough or sneeze . 
 Stay in the house if you have a cold 
 
 5 
 
 
 All clothing clean and sterile at all times 
 Wounds properly disinfected 
 
 5 
 5 
 
 i 
 
 TOTAL 
 
 rn 
 
 ! 
 
 
 J? 
 
 1 
 
 REFERENCE BOOKS 
 
 Adams, The Great American Fraud. American Medical Association. 
 
 Broadhurst, Home and Community Hygiene, Chapter X (Teacher's use). J. B. 
 Lippincott Company. 
 
 Brownell, General Science, Chapter III. Blakiston's Son and Company. 
 
 Chapin, Sources and Modes of Infection (Teacher's use). John Wiley and Sons. 
 
 Clark, An Introduction to Science, Chapter XX. The American Book Company. 
 
 Conn, Bacteria, Yeasts and Molds of the Home. Ginn and Company. 
 
 Conn, Story of Germ Life. D. Appleton and Company. 
 
 Dakin and Dunham, Handbook of A ntiseptics (Advanced). The Macmillan Com- 
 pany. 
 
 Dorset, Some Common Disinfectants. Farmers' Bulletin 926. 
 
 Fisher and Fisk, How to Live. Funk and Wagnalls. 
 
 Harmfulness of Headache Mixtures. Farmers' Bulletin No. 377. 
 Habit-Forming Agents. Farmers' Bulletin No. 393. 
 
 Hill, The New Public Health (Teacher's use). The Macmillan Company. 
 
 Hunter, A Civic Biology, Chapters XI, XXIV. American Book Company. 
 
 Hunter, Laboratory Problems in Civic Biology, Chapter XI. American Book 
 Company. 
 
 Jewett, Good Health. Ginn and Company. 
 
 Lee, Health and Disease (For teachers). Little, Brown, and Co. 
 
 Prudden, Dust and its Dangers. G. P. Putnam's Sons. 
 
 Ritchie, Primer of Sanitation, Chapters XXXI, XXXII. World Book Company. 
 
 Van Buskirk and Smith, The Science of Everyday Life, Project IV. Houghton 
 Mifflin Company. 
 
 Winslow, Healthy Living. Charles E. Merrill Company. 
 
 Zinsser, Infection and Immunity (For teachers). The Macmillan Company. 
 
PART III. HEAT IN THE HOME 
 
 CHAPTER XI 
 FUELS AND THEIR USES 
 
 Problems. i . To learn about fuels and their relative 
 values. 
 
 2 . To find out what burns in fuels. 
 
 3. To learn the difference between " heat " and " tem- 
 perature" 
 
 4. What is the kindling temperature? 
 
 5. How is heat transferred? 
 
 Experiments. 
 
 1. To find out if all substances take fire at the same temperature. 
 
 2. To see if heat will travel along a metal rod. 
 
 Project I. To MAKE A HOUSE THERMOMETER. 
 i Decide what materials are needed, and whether you will make 
 an alcohol or a mercury thermometer. 
 
 2. Practice glass working so that you can blow bulbs in common 
 glass tubing before trying thermometer tubing. Do not try tub- 
 ing with a bore smaller than one millimeter. 
 
 3. The essential operations to learn are : making the bulb, filling 
 it, sealing, and making a graduating scale. 
 
 Suggested Projects. 
 
 I. ARE THE FUELS AT HOME COSTING TOO MUCH? ARE THEY 
 USED EFFICIENTLY? 
 
 175 
 
i 7 6 
 
 FUELS AND THEIR USES 
 
 2. TO MAKE AN ORDINARY SAFETY MATCH. 
 
 3. TO MAKE A FIRE BY PRIMITIVE MEANS WITHOUT MATCHES, 
 BURNING GLASS, OR FLINT AND STEEL. 
 
 4. DIFFERENT METHODS OF BUILDING A FIRE AND REGULATING 
 
 IT WHEN BUILT. 
 
 Sources of fuel. Everybody is familiar with the mate- 
 rials used commonly as fuels such as coal, gas, oil, wood, 
 
 and alcohol. Most 
 fuels come originally 
 from plants, that is, 
 they are organic in 
 origin. Coal, which 
 seems like rock, is 
 really nothing more 
 or less than gradually 
 transformed bodies 
 of dead plants. 
 Prints of leaves and 
 sometimes whole 
 trunks of trees all 
 now transformed 
 into coal are found 
 in coal mines. 
 Specimens of them 
 
 may be seen in our museums. Millions of years ago vegeta- 
 tion became collected in swamps, sank into the earth, and 
 other materials came to lie over this mass of organic matter. 
 Then came pressure, heat, and moisture acting together on 
 this plant material, gradually driving off some of it and leav- 
 ing a hard substance made up very largely of the element car- 
 bon. In some places simitar swamps exist now and are called 
 peat bogs, a poor kind of fuel being dug from them, which, 
 
 Coal beds in the earth. 
 
ECONOMY AND BURNING VALUE OF FUELS 177 
 
 after drying, may take the place of coal or wood. It is be- 
 lieved by many scientists that petroleum and natural gas 
 are also formed through slow chemical changes from dead 
 bodies of plants and animals buried millions of years ago. 
 Great areas holding gas and oil have been discovered in 
 different parts of 
 the United States, 
 the largest produc- 
 tion coming from 
 Pennsylvania, West 
 Virginia, Indiana, 
 Texas, California, 
 Oklahoma, and Illi- 
 nois. Mexico has 
 fields of great value, 
 and oil is found in 
 paying quantities in 
 other parts of the 
 world, southern 
 Russia being one 
 of the richest 
 areas. 
 
 Economy and burning value of different fuels. Wood 
 is used the world over, and is probably used now in more 
 homes than any other fuel. Hardwood, such as hickory, 
 oak, maple, or beech, burns longer and gives a steadier heat 
 than softwoods, such as poplar, hemlock, or pine, but soft- 
 woods give off heat more quickly. Coal is a much used 
 fuel in our eastern homes, soft coal being used more where 
 it is abundant. Soft coal is much dirtier, but somewhat 
 cheaper than hard coal, or anthracite. Coke, which is coal 
 from which certain gases have been removed, is valuable 
 
 H.-WHIT. CIV. SCI. IN THE HOME 12 
 
 In an oil region. 
 
i 7 8 
 
 FUELS AND THEIR USES 
 
 for a quick and hot fire. Natural gas, where abundant, 
 is both cheap and an excellent fuel, while artificial gas has 
 come into many homes to be used as an ideal fuel for 
 cooking. Some homes, indeed, have come to use elec- 
 tricity, and it is believed by scientists that when our great 
 coal and oil resources have been exhausted, we shall depend 
 still more upon electricity produced from water power as a 
 source of heat in our homes. An interesting home project 
 would be a study of the costs of the fuels used in your 
 own home. Fill out a table like the one shown below, 
 
 FUELS USED IN MY HOME 
 
 FUELS 
 
 AMOUNT 
 
 DATE PURCHASED 
 
 COST 
 
 USE 
 
 
 
 
 
 
 giving the kind of fuel, the amount bought on each date, 
 and for what purpose the fuel is used. Is it more econom- 
 ical to buy in small or large quantities? A study of the 
 second table on a comparison of fuels shows that different 
 fuels have a very different heating value, but as their cost 
 in the different localities differs so greatly, this table would 
 have to be modified by each boy and girl who uses it, for 
 his own locality. 
 
 Heating value of fuels. It is of some interest to com- 
 pare the available heat produced by different fuels. In 
 the following table is shown the amount of water which 
 can be heated from the freezing point to the boiling point 
 for one cent at specified prices, provided no heat is lost. 
 It is understood, of course, that no heating device will 
 
WHAT IS IT THAT BURNS IN FUELS? 
 
 179 
 
 QUANTITIES OF HEAT OBTAINED FROM VARIOUS FUELS FOR 
 ONE CENT 
 
 FUEL 
 
 PRICE 
 
 Gallons of water heated from 
 freezing to boiling point if 
 no heat is lost. 
 
 Soft wood 
 Hard wood 
 Soft coal 
 Hard coal 
 Coke 
 Charcoal 
 Kerosene 
 Natural gas 
 Manufactured gas 
 
 $15.00 per cord 
 1 6. oo. per cord 
 lo.oo per ton 
 15.00 per ton 
 12.00 per ton 
 80.00 per ton 
 .20 per gal. 
 .50 per looo cu. ft. 
 1.50 per 1000 cu. ft. 
 
 14 
 20 
 17 
 13 
 13 
 
 2.6 
 
 4.1 
 13 
 
 2.8 
 
 give one hundred per cent 
 so in practice, you could 
 boiling point as is indi- 
 cated by the table above. 
 
 If you wish to heat 
 only a kettle full of water 
 the coal range gives 
 much less efficient serv- 
 ice than the gas range, 
 even though gas may 
 cost more for a given 
 number of heat units. 
 Do you see why this is? 
 
 What is it that burns 
 in fuels ? If you hold 
 a clean glass plate in the 
 flame of a candle, you 
 will notice a thick, black 
 -deposit gather on that 
 part of the plate exposed 
 to the flame. This ma- 
 
 efficiency in the burning of fuel, 
 not heat as much water to the 
 
 Carbon from a candle. 
 
i8o 
 
 FUELS AND THEIR USES 
 
 terial is almost pure carbon. A little thought must con- 
 vince one that it comes from the candle. If we hold a 
 
 well-dried funnel over the candle 
 flame, we find drops of mois- 
 ture on the inside of the fun- 
 nel. We know the water did 
 not come from the air, because 
 no water settled on the walls 
 of the funnel before the candle 
 was placed under it, therefore 
 we conclude that a burning 
 candle produces water. If we 
 now make some hydrogen gas by 
 pouring a little hydrochloric acid 
 over zinc, and then pass it 
 through a drying chamber as 
 shown in the diagram, we can 
 burn the gas in air. Let us be- 
 fore lighting the gas allow it to 
 pass for two or three minutes 
 into a dry, cold funnel. Watch 
 the inside of the funnel carefully. 
 Does anything happen? Now 
 light the colorless gas and invert 
 the funnel over the flame as 
 before. You will notice that 
 water appears on the inside of the 
 funnel. Since water is formed 
 
 Water is a product of burning hy- 
 drogen. 
 
 both by the burning of the candle and the burning of hydro- 
 gen, it appears that hydrogen is also in the candle. All fuels 
 contain carbon. Most fuels contain carbon and hydrogen 
 as well, and many contain other substances in addition. 
 
THE KINDLING TEMPERATURE 
 
 181 
 
 Experiment. To find out if all substances take fire at the same temperature. 
 
 Materials: Tin plate or sheet iron. Sulphur. Phosphorus. Wood. 
 Ring stand. Clamp. Burner. 
 
 Method: Support the sheet iron horizontally with a clamp attached to 
 ring stand. Place a few short pieces of wood (broken match stems) 
 on the middle of the 
 iron plate, and two 
 inches distant from 
 this place on one 
 side a lump of sul- 
 phur the size of a 
 pea, and on the other 
 side a piece of phos- 
 phorus the size of a 
 rice grain. (Do not 
 handle phosphorus 
 with the bare hands 
 and always cut it 
 under water.) Place a low flame under the middle of the iron. 
 The iron distributes the heat so quickly that we may assume that 
 all the materials are being warmed equally at the same time. Each 
 time one burns we may turn the heat on a little stronger. 
 
 Observations: Note the appearance of smoke, the melting of the sub- 
 stances, and the order of taking fire. 
 
 Conclusion: The temperature at which a substance takes fire is known 
 as the kindling temperature. What does this experiment show you 
 in regard to kindling temperatures of sulphur, phosphorus, and 
 wood? 
 
 The kindling temperature. It is evident that different 
 substances take fire at different intensities of heat. The 
 intensity or degree of heat is called temperature. In the 
 experiment, we found that the phosphorus burns first, then 
 the sulphur, while a much higher flame is necessary to 
 make the wood burn. Evidently some substances kindle 
 at a much lower intensity of heat than others. If we now 
 use a thermometer, an instrument used for detecting dif- 
 ferent intensities of heat, or temperatures, we can find the 
 exact kindling temperatures of many substances. 
 
182 
 
 FUELS AND THEIR USES 
 
 How temperature is measured. What do we mean by 
 temperature? We are aware that our bodies are warm, 
 and that ice is cold. Measured in de- 
 grees of temperature, the body is 98.6 
 degrees, while melting ice is 32 degrees 
 Fahrenheit. The common house ther- 
 mometer is an instrument consisting of 
 a fine bore, sealed glass tube with a bulb 
 at the lower end. Mercury or colored 
 alcohol fills this bulb and extends part 
 way up the tube. As heat makes mer- 
 cury expand, it rises in the tube when 
 it gets warmer, and degrees of temper- 
 ature are marked on the thermometer 
 (see diagram). There are two kinds of 
 measurements, the one used by scien- 
 tists, known as the Centigrade scale, 
 while the Fahrenheit scale is used in this 
 country for ordinary purposes. Ther- 
 mometers have come into very general 
 use, and we should all know how to read 
 them and understand what they mean. They are useful 
 as regulating devices in cooking, as we often find them in 
 the oven doors. We also use them for regulating the 
 temperature of our rooms. The room temperature should 
 never be allowed to go over 70 degrees Fahrenheit in winter 
 
 House thermometer. 
 
 Clinical thermometer. 
 
 and the air should not be allowed to get dry, as such con- 
 ditions increase our liability to colds when we leave the 
 house to go out of doors. One type of thermometer has 
 
HOW TO MAKE A FIRE 183 
 
 become a household necessity. This is the clinical ther- 
 mometer which is used in order to detect any change in 
 the temperature of the body from normal, or 98.6 degrees. 
 Body temperature changes are the surest indication that 
 something is wrong within, for fever always shows the 
 presence of toxins or poisons in the blood, and may mean 
 serious illness. In case of a high temperature or fever a 
 physician should always be called. 
 
 Study of a match. Fire making has improved greatly 
 since the days when the Indian rubbed a pointed stick 
 into a hole in another stick in order to obtain a light 
 through the heat evolved by the rapid rubbing or friction. 
 The flint and steel of our forefathers made use of per- 
 cussion in obtaining fire, and the modern friction match 
 makes scientific use of the different kindling temperatures 
 of different substances. We have seen that phosphorus 
 kindles at a lower temperature than most substances, but 
 white phosphorus is poisonous and its use in making 
 matches has been prohibited by law, so that the ordinary 
 match head now contains a mixture of a phosphorus com- 
 pound combined with potassium chlorate, powdered glass 
 or sand, and glue. By rubbing this enough heat develops 
 so that it. lights. In the safety match the head is made up 
 of some substance that burns at a low temperature while 
 red phosphorus is placed on the box, combined with sand or 
 powdered glass to give it a rubbing surface. This prevents 
 the match from being lighted without the phosphorus on 
 the box to aid it in its ignition. 
 
 How to make a fire. The following simple experiment 
 will show one factor necessary to start a fire. Cover a 
 burning candle with a lamp chimney so that it is closed 
 at the bottom but open at the top. The candle gradually 
 
184 
 
 FUELS AND THEIR USES 
 
 No air inlet ; 6, No air out- 
 let ; c, Has both inlet and 
 outlet. This gives a good 
 draft. 
 
 goes out. Now cover the lamp chimney with a piece of 
 cardboard and bring it over the lighted candle again, but 
 leave an open space under the chim- 
 ney. Again the candle goes out. 
 Light the candle and place the 
 chimney over it, leaving the chim- 
 ney open at both top and bottom. 
 The candle burns. 
 
 A study of the burner of a kero- 
 sene lamp shows that air passes in, 
 as in the case of the candle, under- 
 neath the flame, and passes up out 
 of the top of the chimney. By holding the hand, or by 
 placing a small light object over the top of the chimney, 
 the passage of air is noticed. The burner of a lamp regu- 
 lates the air supplied to 
 the flame, which goes 
 out if the air supply is 
 cut off, as was shown in 
 the case of the candle. 
 Evidently a current of 
 air is necessary to make 
 fire burn. These cur- 
 rents which are in circu- 
 lation after the fire starts 
 are known as convection 
 currents, and as we shall 
 see in a moment, are im- 
 portant factors in heat- 
 ing our homes. In order 
 to start a fire in the kitchen stove or open fireplace, we 
 put in a piece of paper and cover it with some shavings 
 
 How air circulates in the common oil lamp. 
 (After Clark.) 
 
THREE METHODS OF DISTRIBUTING ,HEAT 185 
 
 
 
 
 or fine kindlings, and a few small sticks on top in such a 
 way that air can circulate around the fuel. Light the paper 
 at the bottom and the fire is started. If we were to shut 
 off the upper draft in the pipe by closing the damper, or 
 if we were to close the lower door in the stove so as to 
 cut off the current of air from below, the fire would smolder 
 and go out. Air with its constant supply of oxygen is 
 necessary to keep a fire burning. We say the hot air 
 rises. But, as a matter of fact, warm air 
 is lighter than cold air and the cold air is 
 pulled downward with such force by gravity 
 that the warm air is crowded out of the 
 way. Thus smoke made up largely of hot 
 gases is pushed up the chimney. 
 
 Three methods of distributing heat. - 
 We have all seen that heated currents of 
 air are carried up by convection. Thus heat 
 is moved about in the room by means of 
 currents of air. The air as it moves gives 
 heat to cooler bodies, and thus to a great Coi}vection currents 
 extent the rooms of our houses are warmed. j ate a r vessel of 
 But heat also moves through space where 
 there is no air. We all know that the sun keeps us warm, 
 but do we all know that its heat travels through vast 
 areas of space in which no air exists ? This space is filled 
 with ether, and through the ether heat moves by means 
 of waves. This method of heat transference is called 
 radiation. Some surfaces absorb heat much more rapidly 
 than others. Scientists know that black or dull sub- 
 stances do this much better than light or shiny substances, 
 and substances which absorb heat readily give it up 
 easily by radiation. May this be a reason for our black 
 
1 86 
 
 FUELS AND THEIR USES 
 
 stoves and dull radiators? Still a third method of heat 
 transference is the passing of heat from one particle of 
 material to another. This is called conduction. A very 
 interesting experiment shown in the figure illustrates this 
 method of heat transference. The heat received by one 
 set of particles is passed on to others, and by them to 
 still others. Most metals are very good conductors. Some 
 substances, like glass, water, and many rocks, are fair con- 
 ductors, while air, wood, paper, and linen, silk, and woolen 
 fabrics are poor conductors. This principle of non-con- 
 duction is used in making the tireless cooker, the thermos 
 bottle, and the ice chest, where the heat is kept inside in 
 one case, and outside in the other. Solids are the best 
 and gases the poorest conductors of heat, air being one of 
 the best heat-insulating (non-conducting) materials. Con- 
 vection can take place only in liquids and gases. Remem- 
 ber that all these methods of transference of heat are at 
 work in heating our homes. 
 
 Experiment. - 
 
 Materials: 
 
 - To see if heat will travel along a metal rod. 
 A metal rod 15 to 20 inches long. Ring stand and 
 
 clamp. Burner. Wax. 
 Thread. 
 
 Method: Tie a short 
 thread to each of six 
 tacks. Attach these two 
 inches apart to the 
 metal rod by means of 
 melted wax. Support 
 the metal rod so that 
 one end is in the flame 
 of the Bunsen burner. 
 Observation: Notice the 
 order of the melting of 
 the wax and dropping of the tacks. What does this suggest? 
 
 Conclusion: What does this experiment teach about conduction of heat? 
 
REFERENCE BOOKS 187 
 
 REFERENCE BOOKS 
 
 Allen, Sweden and Safety Matches. Ginn and Company. 
 
 Ashmead, The Man Who Mines our Coal. Scientific American, May 18, 1918. 
 
 Barber, First Course in General Science, Chapter I. Henry Holt and Company. 
 
 Clark, Aft Introduction to Science, Chapters I, II, IV. American Book Company. 
 
 Cleland, Geology, Physical and Historical, Chapter XVI {For teachers). American 
 Book Company. 
 
 Fall, Science for Beginners, Chapters XI, XXV. World Book Company. 
 
 Faraday, Chemical History of a Candle. Harper Brothers. 
 
 Forman, Stories of Useful Inventions: The Century Company. 
 The Efficient Use of Coal. Century, February, 1918. 
 
 Greene, Coal and the Coal Mines. Houghton Mifflin Company. 
 
 Ilodgdon, Elementary General Science. Hinds, Hayden and Eldredge. 
 
 Lynde, Physics of the Household, Chapters VIII, IX, X. The Macmillan Com- 
 pany. 
 
 Maron, The Origin of Inventions (Fire making). Charles Scribner's Sons. 
 
 Mumper, Text-Book in Physics. Ameri :an Book Company. 
 
 Routledge, Discoveries and Inventions of the Nineteenth Century, pages 646-652. 
 Routledge. 
 
 Stone, Making a Match. General Science Quarterly, Salem, Mass., January, 1919. 
 
 Tappan, Makers of Many Things (Matches). Houghton Mifflin Company. 
 
 Toothaker, Commercial Raw Materials (Coal and Oil). Ginn and Company. 
 
 Van Buskirk and Smith, The Science of Everyday Life, Project II. Houghton 
 Mifflin Company. 
 
 Venable, History of Chemistry (For teachers). D. C. Heath and Company. 
 
 Whitman, How to Make a Thermometer. General Science Quarterly, May, 1920. 
 
CHAPTER XII 
 HEATING OUR HOMES 
 
 Problems. i. To see how our homes are warmed. 
 
 2. To find out how heating devices are constructed. 
 
 3. To learn the best way of regulating the fire in the stove 
 or furnace. 
 
 4. To see how heat is used in cooking. 
 
 5. To understand how the hot-water supply system is 
 operated. 
 
 6. To learn how to find the amount of gas consumed. 
 
 Experiments. 
 
 1. To show the principle of hot- water heating. 
 
 2. To show the great amount of heat stored in team. 
 
 3. To show how to produce luminous and non-luminous gas flames. 
 
 Project I. To QUALIFY AS AN EXPERT HEATING DEVICE OPERATOR 
 
 IN MY HOME. 
 
 1. To start fires quickly without use of kerosene. 
 
 2. To control the fire properly: to keep the house evenly heated; 
 to have the oven at the proper temperature at the right time. 
 
 3. To increase the humidity of the air when needed, and to secure 
 ample ventilation. 
 
 4. To adjust the air mixer on gas burners. 
 
 5. To clean out clogged and dirty gas burners. 
 
 6. To prevent needless heat loss from any cause. 
 
 7.. To prevent the existence of fire hazards from any heating 
 device. 
 
 188 
 
HOW HEAT IS USED IN OUR HOMES 
 
 189 
 
 Project II. To LEARN HOW MY COAL RANGE is CONSTRUCTED 
 
 AND HOW TO RUN IT. 
 
 Study coal range at home. Find out what the different parts are 
 for and how they are related to each other. Make a cross section 
 diagram across the fire box and oven. Use arrows to show circu- 
 lation of gases from room to stovepipe when oven is being heated. 
 Use dotted lines to suggest necessary passages which would not 
 show in cross section. Make a chart like the one below and fill 
 in the blank spaces, indicating how you would regulate fire to meet 
 different conditions. Include the following table completed in your 
 report of this project. 
 
 
 DRAFT IN 
 ASHPIT 
 DOOR. 
 
 (A) 
 
 SLIDE m 
 FUEL DOOR. 
 
 (B) 
 
 DAMPER ON 
 STOVEPIPE. 
 
 (C) 
 
 CHECK 
 DRAFT IN 
 STOVEPIPE. 
 CD) 
 
 Starting a fire 
 
 
 
 
 
 Keeping a moderate fire . 
 
 
 
 
 
 Cooling an overheated stove . . 
 
 
 
 
 
 To keep a fire overnight . . . 
 
 
 
 
 
 Additional Projects. 
 
 I. TO DETERMINE HOW MUCH . FUEL CAN BE SAVED BY USING A 
 FIRELESS COOKER FOR COOKING CERTAIN FOODS. 
 
 2. TO UNDERSTAND THE HOT- WATER SUPPLY IN MY HOME. 
 
 3. TO UNDERSTAND HOW HEAT IS TRAPPED IN A SUN PARLOR, 
 AND COLD FRAME. 
 
 Thought Question. 
 
 i. Why does not the cold water enter the hot-water tank through 
 a pipe at the bottom of the tank rather than through the one from 
 the top ? 
 
 How heat is used in our homes. Without heat for 
 warming our houses and cooking our foods, home would 
 be a dreary place. We do not always appreciate the hot, 
 well-cooked dinner, warm rooms, and the cheerful fireplace 
 
HEATING OUR HOMES 
 
 because these things have long been commonplace. Heat 
 has become a servant of man, and fire is harnessed in 
 many ways that would be strange to our forefathers. As 
 good home makers, we should learn about the devices used 
 for heating and cooking in the home. 
 
 The coal stove. The ordinary coal stove used for 
 heating or cooking is really a metal box arranged so as 
 to admit air for combustion, and to carry the products of 
 
 'Pilpe to C"KT-nxT\ey 
 ^"^J Check Damper- 
 
 -avH 
 
 "Directive 
 
 The coal range. Point out the place for the check draft. 
 
 combustion up the chimney. The coal rests on the grate 
 and is burned in the fire box. Below the grate is a com- 
 partment to hold ashes, called the ash pit. Each compart- 
 ment has a door with openings and slides in it. The 
 openings in the lower door form the draft, and those in the 
 upper door the check draft. In the stove pipe, which leads 
 to the chimney, there is another device for controlling the 
 air currents called the damper. 
 
 Regulation of fire. In starting the fire, the lower draft 
 and the damper should be open, but the check draft should 
 be closed. This allows the poisonous carbon monoxide 
 
HOW A ROOM IS WARMED 
 
 191 
 
 which comes from coal, to escape up the chimney. The 
 hottest fire is obtained when the damper and draft are 
 both open and the check draft closed, as this allows a 
 free passage of air through the burning coal. By open- 
 ing the check draft, closing the draft, and partially closing 
 the damper, the fire will burn slowly. By closing the 
 damper completely, the air current is checked and burning 
 almost stops. If the room is overheated, close the draft, 
 open the damper and the upper door of the stove. The 
 air from the room will then rush in over the coal and pass 
 up the chimney, thus cooling the stove without helping 
 the materials to burn. In checking the fire, always close 
 the draft. If the draft is left open and the damper 
 closed, the poisonous gas, carbon monoxide, may escape 
 into the room. A very small percentage of this gas in the 
 air is fatal. Carbon monoxide has no odor to warn of 
 its presence and people have been suffocated while sleep- 
 ing in a room with a 
 stove in which the 
 fire was checked in- 
 correctly. 
 
 How a room is 
 warmed. In the 
 case of the old- 
 fashioned fireplace, 
 although it is still 
 used because of its 
 coziness and good 
 cheer, very little 
 heat is given to distant parts of the room, most of the heat 
 going up the chimney. The stove transfers to the room by 
 convection and radiation about seventy to eighty per cent 
 
 Convection currents caused by a hot stove. 
 
IQ2 
 
 HEATING OUR HOMES 
 
 of the heat obtained from the fuel. Air coming in contact 
 with the hot surface of the stove expands and becomes 
 lighter, and is pushed up by heavier air, which comes in to 
 take its place (see arrows in diagram). These warm cur- 
 rents of air become cool as they pass by the windows and 
 cold walls and other surfaces which absorb heat, and sink 
 
 again to the floor. 
 Since the stove is 
 warmer than other 
 objects in the room, 
 it radiates heat to 
 them; heat is 
 brought also through 
 the metal from the 
 inside to the outside 
 surface by conduc- 
 tion. Thus all three 
 methods of heat 
 transference are used 
 to some extent in 
 heating a room. 
 
 The hot-air fur- 
 nace. The hot-air 
 furnace has come 
 into general use and 
 is much liked because it does the work of several stoves 
 and requires no more attention than one. The furnace is 
 simply a large central stove placed in the cellar, and cov- 
 ered with a metal jacket, from the top of which metal 
 tubes, or ducts, lead out to the different rooms to be 
 heated. Air from out of doors is brought to the bottom 
 of the space between the fire box and the inclosing jacket, 
 
 A hot-air furnace. 
 
ADVANTAGES AND DISADVANTAGES OF HOT AIR 193 
 
 and as it becomes hot, rises and passes through the pipes 
 to the various rooms. A study of the diagram on page 
 192 shows that nearly the same method of heat transfer 
 takes place in the furnace as in the case of the stove. 
 
 Regulation of the air supply. It is well to remember 
 that air when heated increases in volume from five per 
 cent in cool to over twenty per cent in extremely cold 
 weather. For this reason less cold air should be let into 
 the furnace through the cold air flue in very cold weather. 
 The small slide used to regulate this volume of air (see 
 S in diagram) should be adjusted according to the weather 
 outside, otherwise much coal may be wasted in order 
 to keep the rooms warm. Some houses have a system 
 by which the warm air after circulating through the 
 rooms is sent to the furnace to be warmed again. This 
 is more economical of heat, but does not give as good 
 ventilation. 
 
 Advantages and disadvantages of the hot-air furnace. 
 The hot-air furnace is less expensive to install than 
 either steam or hot water, is easily operated, and gives up 
 heat quickly. The disadvantages of a furnace in a large 
 residence are that the long horizontal pipes do not take 
 heat to the distant rooms leading against the force of the 
 wind. The hot-air furnace heats irregularly, and is un- 
 satisfactory on days when there is a strong wind, and after 
 it becomes old gives off much dust and some gas into the 
 house. 
 
 Experiment. To show the principle of hot- water heating. 
 
 Materials: Apparatus shown in diagram. 
 
 Method: Fill the apparatus with water. This can be done by pouring 
 water into the tank at the top and opening the clamp at the top of 
 the bent tube until water fills both tubes. Close the clamp. Drop two 
 or three crystals of potassium permanganate through the rubber tube 
 
 H.-WHIT. CIV. SCI. IN THE HOME 13 
 
194 
 
 HEATING OUR HOMES 
 
 into the glass tube, connect the tubes and fill the tank partly fullof 
 
 water. Open the clamp. Heat the flask. 
 Observation and Explanation: Notice all changes. Describe everything 
 
 that happens. Explain what parts of a hot- water heating system 
 
 are represented by the 
 different parts of the ap- 
 paratus. 
 
 The hot-water 
 heating system. - 
 In the hot-water 
 heating system, we 
 have a combined 
 furnace and boiler 
 in the cellar, radia- 
 tors in the rooms, 
 connecting pipes to 
 bring the water to 
 the radiators and 
 back to the boiler, 
 and a tank known 
 as the expansion 
 tank at the top of 
 the house, in which 
 the water may rise 
 
 Hot-water heating system at the left, and apparatus to 
 illustrate it at the right. 
 
 as it expands. The principle of heat transfer from the boil- 
 ers to the radiators is that of convection. The water in 
 the boiler is never heated to the boiling temperature. It 
 enters the radiators at a temperature of 175 to 185 degrees 
 Fahrenheit, and leaves it ten degrees colder. This differ- 
 ence in temperature causes the water to grow heavier, and is 
 responsible for the flow through the pipes. 
 
 How a room is wanned by hot water. As soon as the 
 hot water reaches the radiator, heat is conducted through 
 
STEAM HEAT IN THE HOME 195 
 
 the metal to the outside surfaces. Air coming in contact 
 with the radiators is heated, and this heat is given to 
 other objects in the room by convection, while some heat 
 is radiated directly to the walls and objects in the room. 
 Thus the room is heated by convection more than by 
 radiation, and we have a more even distribution of heat 
 than by stove or by steam. One drawback to the hot- 
 water system is the fact that in the sleeping rooms we 
 cannot cut off the heat without danger of freezing the 
 water in the radiator. The best plan for those who like 
 to sleep with the windows open is to cover the radiator 
 at night with a heavy blanket or some good non-conduct- 
 ing substance. 
 
 Advantages and disadvantages of hot water. This is 
 one of* the most expensive systems to install, but it is more 
 economical to operate than the hot-air furnace or the stove. 
 With it the rooms may be kept at an even temperature, 
 but unfortunately, if the water gets cold it takes a long 
 time to warm it up. As the system provides no ventila- 
 tion, we must secure fresh air in some other way. An ex- 
 cellent system is the combination of hot water and hot air, 
 in which the boiler is situated in the top of the furnace, 
 and the water thus heated is passed to rooms far distant 
 from the furnace. 
 
 Steam heat in the home. In the steam-heating systems, 
 the parts are practically the same as in the hot-water 
 system, except that there is no expansion tank and the 
 pipes are closed throughout. Steam made by boiling water 
 passes through the pipes to the radiators. In the radiators 
 the steam condenses, giving off its load of heat. The 
 water formed by this condensation leaves the radiator and 
 is brought back to the furnace again, either by a system 
 
ig6 
 
 HEATING OUR HOMES 
 
 of return pipes, or if the house is small, it may return 
 through the steam pipe. 
 
 Experiment. To show the great amount of heat stored in steam. 
 Materials: Calorimeter (a soup can will do). Flask. One-hole stopper 
 and tube. Rubber tubing. Steam trap. Thermometer. Ring 
 stand. Burner. 
 
 Steam-heating system. 
 
 Method and Observation: (a) Weigh the calorimeter half full of cold 
 water. Record the temperature. Boil the water in the flask. Con- 
 nect the steam trap and when the water is boiling put the free end of 
 the trap into the cold water. Let it run for about five minutes. Re- 
 move the trap. Stir well, and take the temperature. Weigh. What 
 has caused this increase in weight? How many degrees in tempera- 
 ture was the water warmed by the steam? (b) Fill the calorimeter 
 again with the same quantity of cold water used in (a), and at the 
 same temperature. Pour into it a quantity of boiling water equal in 
 weight to that of the steam added in (a). What is the rise in tem- 
 perature? 
 
PROTECTION AGAINST LOSS OF HEAT 197 
 
 Conclusion: Which will give the larger quantity of heat, a given weight 
 of water at the boiling point, or the same weight of steam at the same 
 temperature? Which is hotter, steam or boiling water? If you are 
 not sure, make a test. 
 
 Advantages and disadvantages of steam heating. - 
 
 Although less coal is used in steam heating than in most 
 other systems, no ventilation is supplied and an uneven 
 temperature is produced, the room sometimes being very 
 hot and sometimes very cold. One needs to be quite an 
 engineer to run this system properly. The snapping or 
 pounding in the steam pipes is caused by what is known as a 
 water hammer, which is produced by the water suddenly 
 rushing into a vacuum, and striking .the pipe or the other 
 water there a hard blow. When steam in the steam-heating 
 system suddenly comes in contact with the cold radiator, 
 it condenses, and a vacuum is produced. If there is water 
 in the pipes with pressure behind it, that is, steam coming 
 from the boiler, it may be sent through this vacuum with 
 great speed, and made to strike a hard blow against the 
 metal pipes. The remedy is to admit steam slowly when 
 first warming up the cold system. Steam, like hot water, 
 has an advantage over the hot-air system in that it 
 carries no dust. Because of the high temperature of the 
 radiators, they need to be only about two thirds of the 
 size of hot water radiators. Steam is used with good re- 
 sults in warming large buildings. 
 
 Protection against loss of heat. Much heat is often 
 lost through the radiation from pipes in the cellar. A 
 good plan is to have these pipes covered with some in- 
 sulating substance, so that the heat will be retained and 
 delivered where it is needed. Much leakage of cold air is 
 often found around windows and doors. If the window 
 
198 HEATING OUR HOMES 
 
 rattles, you can be sure that cold air is leaking into the 
 house. One way to prevent this is by placing weather 
 strips along on the outside of the window where it fits 
 into the sash. A much better method of keeping out cold 
 air is by means of the double window. Ventilation may 
 be obtained through a loose pane on hinges which can be 
 opened when desired. The storm door, which is nothing 
 more than a double door sometimes arranged with a tiny 
 antechamber in which one may wait while the inner door 
 is being opened, is another means of keeping out much 
 cold air, especially where there are high winds. 
 
 The use of heat in cooking. In the coal range we have 
 the same principle as. the coal stove, except that on one 
 side of the fire box there is an oven separated from the 
 outside walls of the stove by a space. Heat is circulated 
 through this space to warm the oven. A knowledge of the 
 drafts and dampers is necessary in order to heat the oven 
 properly. The main air supply enters through a draft 
 into the ash pit under the coal, passes through the layer of 
 hot coal, helps it to burn, and the hot gases coming from 
 the burning coal pass around the oven and escape up the 
 stovepipe. (Seep. 190.) The oven damper, if raised, causes 
 these gases to pass around the oven before entering the stove 
 pipe. When the oven damper is down, the hot gases pass 
 directly out. What would you do to cool the oven? 
 
 The oven temperature. We can control the oven 
 temperature by regulating the size of the fire, by the use 
 of the oven damper, and by opening the oven door. We 
 must remember that some things, such as roast meats, 
 require a high temperature, while custard requires a much 
 lower temperature. The accompanying table shows some 
 of the differences in temperature for cooking different foods. 
 
THE GAS RANGE 
 
 199 
 
 OVEN TEMPERATURES FOR BAKING VARIOUS FOODS 
 
 Searing Roasts . . . 500 F 
 
 Biscuit 450 
 
 Pies 400 
 
 Bread 35oF 
 
 Layer Cake .... 300 
 Custard 250 
 
 Experiment. How to produce a luminous and a non-luminous gas flame. 
 
 Materials: Bunsen burner. Chalk dust. 
 
 Method and Observations: Close the air holes near the base of the burner. 
 
 Light the gas. Describe the flame. Open the air holes. What 
 
 change in flame occurs? When you have a clear non-luminous flame, 
 
 blow a little chalk 
 
 dust into the air 
 
 holes. Effect on the 
 
 flame ? Place a piece 
 
 of heavy white paper 
 
 down over the lumi- 
 
 nous flame for an 
 
 instant. What is the 
 
 product ? 
 Conclusion: From these 
 
 results try to give a 
 
 reason why the gas 
 
 flame is luminous 
 
 when no air is mixed 
 
 with it. What is 
 
 the part that car- 
 
 bon plays in a lumi- 
 
 nous flame? What 
 
 type of burner is 
 
 best for cooking de- 
 
 vices? 
 
 Top burner of the gas range. 
 
 The gas range. 
 
 In many homes 
 
 where gas is avail- 
 
 able, the gas range 
 
 has supplanted the coal or wood stove for cooking. It 
 
 is not only quicker, cleaner, and more convenient, but. 
 
 especially if natural gas is available, it is much cheaper, 
 
2OO 
 
 HEATING OUR HOMES 
 
 The top burners have a tube at the base, in which are 
 openings for the entrance of air. The air mixes with 
 gas entering the tube, and the mixed gases are passed 
 through small holes in the burner ring, and burned. 
 This burning should take place with a blue flame. If too 
 little air is admitted, the flame will be yellow, and soot will 
 collect on the cooking utensils. The burner should be 
 kept clean, for dirt clogging the air mixer will cause smoke. 
 The burner can be taken off and 
 boiled in water containing washing 
 soda, and small particles of dirt re- 
 moved by picking out with a fine 
 needle or wire. When lighting the 
 oven one should be careful first to 
 open the oven door, light the pilot 
 flame, and then turn on the gas. 
 A gas stove should have a stove 
 pipe to carry off the gases into the 
 chimney flue. 
 
 The hot-water supply. Hot 
 water has become almost a neces- 
 sity in houses, in the country as 
 well as in the city. The hot-water 
 supply for household purposes is 
 obtained by the use of the hot- 
 water storage tank connected to 
 the coal range or independent 
 Hot-water supply. heater. In the range the water 
 
 is heated by means of a pipe passing close to the fire box, 
 and then running to the boiler. In addition a gas stack 
 is often attached to the tank. In this the gas flame 
 heats a coil containing cold water, the rapidly heated 
 
READING THE GAS METER 
 
 201 
 
 water rises as it becomes lighter, and passes into the pipe of 
 the hot- water tank. When the hot water is drawn from the 
 faucet, a supply of cold water enters through the pipe which 
 enters at the top of the tank and extends down to a level just 
 above the top of the heating device. In the instantaneous 
 gas heater, the gas is automatically turned on and lighted 
 by a pilot flame when the faucet is opened. The water is 
 heated as it passes through the coiled pipes in the flame. 
 Reading the gas meter. Since gas is a commodity which 
 is delivered to our homes, we should learn to read the meters, 
 
 CUBIC 
 
 Recording dials of gas meter. 
 
 so as to be able to know how much gas is burned, and 
 whether we use it economically. The recording device of 
 a small gas meter has three small dials, and a fourth one 
 still smaller on top, which has a scale registering two cubic 
 feet. Above the three dials are marked the figures 100,000, 
 10,000, and 1,000, and the face of each dial is figured from 
 o to 9. When the gas passes through the meter, the hands 
 revolve, the two outer ones in the direction of the hands of a 
 clock, and the inner one in the opposite direction. In the 
 illustration the 100,000 dial hand is between 5 and 6, the 
 10,000 between 5 and 6, and the 1,000 at 8. This means 
 
202 
 
 HEATING OUR HOMES 
 
 that the meter stands at 55800 cubic feet. The last time 
 the meter was read, as the dotted position of the hands shows, 
 it stood at 54200. Another kind of meter is so arranged 
 that a certain amount of gas is given out after placing a 
 coin in a slot in the meter. When this gas is exhausted, 
 the meter automatically cuts off the supply until another 
 coin is dropped in. One may easily check up the amount 
 of gas which can be used before the supply is cut off by 
 reading the special index controlled by the coins inserted. 
 
 Other fuels used in the home. Many people who do 
 not live where gas is piped into the house, use the blue 
 flame kerosene or gasoline stoves. In these stoves the 
 fuel flows from a reservoir down to a wick in the burner, 
 where, as the metal becomes heated, the fuel evaporates, 
 mixes with air and burns in the same manner as does the 
 gas in the gas stove. In practically all stoves using kero- 
 sene or gasoline the blue flame is produced in this way. 
 Alcohol is sometimes used as a fuel where a hot flame is 
 needed for a short time, as with the chafing dish, and 
 most of us have used " solidified alcohol " which now 
 comes in convenient tins for use at any time. In this form 
 of fuel the alcohol is absorbed in a soft wax or paraffin. 
 It must be kept from the air, however, or it will lose the 
 burning properties quickly through evaporation. 
 
 SCORE CARD. HEAT IN MY HOME 
 
 
 
 FAIR 
 
 
 MY 5 
 
 >CORE 
 
 
 
 
 
 
 Total 
 
 WARMTH 
 
 All parts of home 
 warm enough in 
 coldest weather 
 
 All parts of each 
 room can be 
 evenly heated (5) 
 
 Some rooms not 
 warm enough in 
 coldest weather 
 (4) 
 Some rooms evenly 
 heated; others 
 not (3) 
 
 Temperature in all 
 rooms too cold in 
 coldest weather 
 (o) 
 Unequal heating in 
 all rooms, none 
 comfortable i n 
 every part (o) 
 
 
 
 
 
 
 
 
 
SCORE CARD 
 
 203 
 
 SCORE CARD. HEAT IN MY HOME Continued 
 
 
 
 
 
 MY SCORE 
 
 
 T? yi 
 
 FAIR 
 
 VERY POOR 
 
 
 
 HiXCELLENT 
 
 
 
 
 TOTAL 
 
 VENTILA- 
 
 Large supply of 
 
 Small supply of air 
 
 No air in heating 
 
 
 
 TION AND 
 
 fresh air circu- 
 
 circulated in 
 
 circulation (o) 
 
 
 
 PROTEC- 
 
 lated in rooms (2) 
 
 rooms (i) 
 
 
 .... 
 
 
 TION 
 
 All pipes and fur- 
 
 Pipes but not fur- 
 
 No protection of 
 
 
 
 AGAINST 
 
 nace protected 
 
 nace protected 
 
 pipes or furnace 
 
 
 
 LOSS OF 
 
 against loss of 
 
 against heat loss 
 
 (o) 
 
 
 
 HEAT 
 
 heat (2) 
 
 (i) 
 
 
 .... 
 
 
 
 Weather strips, 
 
 Weather strips old, 
 
 No weather strips, 
 
 
 
 
 storm doors, and 
 
 storm doors 
 
 storm doors, or 
 
 
 
 
 storm windows 
 
 leaky, storm win- 
 
 sashes. Win- 
 
 
 
 
 new and tight 
 ventilation sashes 
 
 dows without 
 ventilation sashes 
 
 dows rattle in 
 wind and leak air 
 
 
 
 
 in windows (6) 
 
 
 (o) 
 
 
 
 
 
 \o / 
 
 
 
 
 ECONOMY 
 OF FUEL 
 
 Fuels (except gas) 
 purchased in 
 
 Fuels purchased in 
 small quantities 
 
 Very small quanti- 
 ties purchased as : 
 
 
 
 
 large quantities 
 at one time (4) 
 
 as: i gal. oil; 
 J ton coal (2) 
 
 i qt. oil; i bag 
 coal; i bu. wood 
 
 
 
 
 
 
 (o) 
 
 
 
 
 Wood, coal, coke, or 
 
 Artificial gas used 
 
 No saving attempt- 
 
 
 
 
 natural gas used 
 
 sometimes when 
 
 ed by using 
 
 
 
 
 in kitchen in win- 
 
 have coal or wood 
 
 cheaper fuels (o) 
 
 
 
 
 ter (2) 
 
 fire (i) 
 
 
 
 
 
 Fuel not wasted 
 
 Fuel often saved by 
 
 No attention paid 
 
 
 
 
 in ashes or more 
 
 attention to gas 
 
 to economical use 
 
 
 
 
 gas burned than 
 
 burner and ash 
 
 of gas or to ashes 
 
 
 
 
 needed (2) 
 
 sifting (i) 
 
 (o) 
 
 
 
 
 Electric heat sel- 
 
 Electric heat often 
 
 Electric heat com- 
 
 
 
 
 dom used (2) 
 
 used (i) 
 
 monly used (o) 
 
 
 
 ECONOMY 
 
 No extra dust in 
 
 Little extra dust in 
 
 Much extra dust in 
 
 
 
 IN TIME 
 
 winter (3) 
 
 winter (i) 
 
 winter (o) 
 
 
 
 AND 
 
 No ashes (electric- 
 
 Little ash or 
 
 Much ash or clink- 
 
 
 
 WORK 
 
 ity or gas) (3) 
 
 clinker (2) 
 
 er (o) 
 
 
 
 DONE 
 
 Not more than 15 
 
 Not more than 30 
 
 More than 30 min. 
 
 
 
 
 min. required per 
 
 min. required for 
 
 a day required for 
 
 
 
 
 day for proper 
 
 care of heating 
 
 care of heating 
 
 
 
 
 care of heating 
 
 devices (i) 
 
 devices (o) 
 
 
 
 
 devices (2) 
 
 
 
 
 
 
 Thermostats and 
 
 Lacks either ther- 
 
 No thermostats or 
 
 
 
 
 other heat regu- 
 
 mostats or heat 
 
 heat regulating 
 
 
 
 
 lating apparatus 
 
 regulating appa- 
 
 apparatus (o) 
 
 
 
 
 so that furnace 
 
 ratus (i) 
 
 
 
 
 
 can be regulated 
 
 
 
 
 
 
 without going to 
 
 
 
 
 
 
 cellar (2) 
 
 
 
 
 
 COOKING 
 
 Cooking stove 
 
 Cooking stove 
 
 Cooking stove 
 
 
 
 
 makes no dust or 
 
 makes little dust 
 
 makes much dust 
 
 
 
 
 dirt (electricity) 
 
 or dirt (gas, ker- 
 
 or dirt (wood, 
 
 
 
 
 (2) 
 
 osene) (i) 
 
 coal) (|) 
 
 .... 
 
 
 
 Stove safe (2) 
 
 Stove moderately 
 
 Stove not safe (o) 
 
 
 
 
 
 safe (i) 
 
 
 
 
 
 Stove easy to man- 
 
 Stove moderately 
 
 Stove difficult to 
 
 
 
 
 age (3) 
 
 easy to manage 
 
 manage (o) 
 
 
 
 
 
 (2) 
 
 
 
 
 
 Cooks and bakes 
 
 Cooks well; bakes 
 
 Cooks and bakes 
 
 
 
 
 well (3) 
 
 poorly (i) 
 
 poorly (o) 
 
 
 
 GRAND TOTAL 
 
204 HEATING OUR HOMES 
 
 REFERENCE BOOKS 
 
 Barber, General Science, Chapter II. Henry Holt and Company. 
 Burns, Story of Great Inventions. Harper and Brothers. 
 
 Butler, Household Physics, Chapters on Heat, pages 6-57. Whitcomb and Barrows. 
 Caldwell and Eikenberry, General Science. Ginn and Company. 
 Clark, An Introduction to Science, Chapters I, II, III. American Book Company. 
 Hopkins, Experimental Science (For help in projects). Munn and Company. 
 Lunt, An Illuminating Gas Project. General Science Quarterly, May, 1917. 
 Lynde, Physics of the Household, Chapters VII, XI. The Macmillan Company. 
 Mowry, American Inventions and Inventors. Silver, Burdett and Company. 
 Smith and Jewett, Introduction to the Study of Science, Chapter II. The Mac- 
 millan Company. 
 
 Walrath, Hot Water Boiler Demonstration. General Science Quarterly, Jan., 1918. 
 Williams, How It Works, pages 386-391. Nelson Company. 
 Williams, Introductory Fire Lesson. General Science Quarterly, May, 1917. 
 
CHAPTER XIII 
 FIRE PREVENTION IN THE HOME 
 
 Problems. i. To learn the estimated fire loss in the 
 United States, 
 
 2. To discover the usual sources of fires. 
 
 3. To understand why "fire prevention " is so important. 
 
 4. To learn the principles underlying the putting out of 
 fires. 
 
 5. To see how home fire extinguishers are constructed 
 and used. 
 
 Experiments. i . To show how spontaneous combustion takes place. 
 2. To show how to extinguish 
 
 (a) Burning fat. 
 
 (6) Gasoline. 
 
 Project I. To REMOVE THE FIRE HAZARDS FROM MY HOME. 
 
 1. This requires a good knowledge of fire dangers and the most 
 common sources of fires. 
 
 2. Thorough study of the home with reference to the possibility 
 of fire should be made. 
 
 3. Fire dangers must be removed by appropriate methods. 
 
 4. A complete report will include a discussion of: 
 
 a. Principles. 
 
 b. Conditions found. 
 
 c. Changes made. 
 
 Suggested Project. To MAKE A TOY CHEMICAL FIRE EXTIN- 
 GUISHER. 
 
 205 
 
206 FIRE PREVENTION IN THE HOME 
 
 Fire and its dangers. You may have been fortunate 
 enough never to have lost your home or loved ones through 
 fire, but nevertheless that danger is always with us. It 
 stands ready for the careless moment when you give it an 
 opportunity to burst forth with its suffocating and deadly 
 flames, and many are its victims. Every week the papers 
 have accounts of destruction and suffering caused 
 by fire. Read the following clippings selected 
 from a paper in one week : 
 
 " Mrs. Laura , 33 years old, of 66 Street, died in the 
 
 Southside Hospital to-day from burns suffered when she attempted 
 to hurry a fire hi the kitchen stove by pouring oil over it." 
 
 " Florence S. , three years old, of Avenue, died early 
 
 to-day in the General Hospital from burns received yesterday, when 
 her clothing was ignited from a firecracker." 
 
 " Dozens of lives were imperiled in a fire which destroyed the 
 
 apartments at Avenue early this morning. Some occupants 
 
 were carried out; others jumped from the second story window; 
 three are confined in the hospital. The damage was $4000." 
 
 Here was a financial loss great enough to have 
 bought each one of you in the 
 class two bicycles, a pair of 
 skates, skis, and a good sled. 
 
 " Fire which threatened to wipe out a 
 big section of Homestead caused damage 
 of upwards of $45,000. High winds car- 
 ried sparks and several other fires were 
 started. Fires were only extinguished 
 after aid arrived from surrounding bor- 
 oughs." 
 
 The money loss in this fire 
 
 necessary. (After Richman.) WOU ld have bought each One 
 
 of the pupils in your class an automobile. If reports 
 of fires which have occurred in the entire United States 
 in the last twenty-four hours could be laid on your desk 
 
ENORMOUS FIRE LOSSES 
 
 207 
 
 you would have a collection of about fifteen hundred. 
 Records of past years show that the number of fires 
 averages about fifteen hundred a day ; one every minute. 
 
 Enormous fire losses. The fire loss in the United 
 States for 1919 was '$325,000,000. There were in the 
 United States during 1919 over 5,000,000 fires. Sup- 
 pose these fires spread at equal intervals of time, and the 
 
 $2.10 
 
 Relative per capita fire losses in different countries. 
 
 fire loss was distributed evenly throughout the year, 
 then, 
 
 Every second $10.00 in property is destroyed. 
 
 Every minute a new fire starts somewhere in the United 
 States. 
 
 Every hour two lives are lost and seven persons are 
 injured through fire. 
 
 Every day enough property value is destroyed by fire 
 to feed and clothe a city of 50,000 people for ten days. 
 
 Every week the fire loss is enough to build 100 miles of 
 good macadam road. 
 
 Every month the loss from fire is equivalent to a sum of 
 money which would buy the grounds, erect the buildings, 
 
208 FIRE PREVENTION IN THE HOME 
 
 and provide an endowment to pay the running expenses 
 of a large college. 
 
 In a year, the money value of fire losses would pay 
 salaries, books, and supplies for all public education in the 
 entire United States for more than half a year. 
 
 Charles W. Baker, in an address entitled " A Street of 
 Desolation," said in speaking of the damage done in a 
 single year that " the buildings consumed, if placed on 
 lots of 65 feet frontage, would line both sides of a street 
 extending from New York to Chicago. A person jour- 
 neying along this street of desolation would pass in every 
 thousand feet a ruin from which an injured person was 
 taken. At every three quarters of a mile in this journey 
 he would encounter the charred remains of a human being 
 who had been burned to death." 
 
 Why are there so many fires ? Are these losses by 
 fire necessary? What causes the fires? Many fires are 
 reported as " cause unknown," but a study of the causes 
 in a large number of other cases shows that the principal 
 cause of fires is CARELESSNESS. No one of us can truth- 
 fully say that he has not been careless about such mat- 
 ters. It is time that we begin a new era of thoughtful, 
 careful attention to the ways and means of safeguard- 
 ing the home, the business houses, and the factories 
 against fire. 
 
 Sources of fires in the home. The cause of about 90% 
 of the fires is carelessness in regard to a few things about 
 the home. Some of the most important things about 
 which we ought to be more careful are : 
 
 a. The use of kerosene and gasoline. 
 
 b. Matches and all uncovered flames. 
 
 c. The heating plant, stove pipes, and chimney. 
 
FLAMES FOR LIGHT 
 
 209 
 
 d. Electrical devices and wiring. 
 
 e. Oily rags and other rubbish. 
 
 Matches. In the United States half a million flames 
 are produced with matches on an average every minute. 
 Every bare flame has the possibilities of serious conse- 
 quences. Our chief concern in the house as regards matches 
 is to keep them away from children who are too young 
 to realize the danger, and from rats and mice, which are 
 known at times to cause fires by gnawing the match heads. 
 Nearness to heated pipes or flues at times ignites matches. 
 Protection against ani- 
 mals is secured by in- 
 closing in a covered 
 metal or earthenware 
 box. This will also 
 smother the flame 
 quickly if set on fire 
 from a near-by source 
 of heat. Placing on a 
 high shelf or in a locked 
 closet or drawer is usu- 
 ally sufficient protection 
 against the small child. 
 
 Flames for light. - 
 The candle, kerosene 
 lamp, and gas flame are 
 common sources of dan- 
 ger in the home. The 
 candlestick and lamp should have a low center of gravity and 
 a broad base to guard against tipping over. Unprotected 
 paper or cloth shades for candles are extremely dangerous. 
 A mica chimney should separate the flame from the shade. 
 
 H.-WHIT. CIV. SCI. IN THE HOME 14 
 
 Which lamp is the greater fire hazard ? 
 
2IO 
 
 FIRE PREVENTION IN THE HOME 
 
 The danger from lamps comes largely from leaving them 
 for a time, from dropping them when carrying them about, 
 and from filling them when lighted. Never leave a burn- 
 ing lamp in a room by itself for any length of time. Use 
 only lamps with metal reservoirs. Always fill lamps by 
 daylight. Keep the lamp always in good order. Obser- 
 vation of these simple rules will do much to prevent serious 
 fires. 
 
 Fire dangers from heating devices. Disastrous fires 
 from chimneys, stoves, furnaces, and portable heaters 
 
 are common. Perhaps most 
 deaths from burning come 
 from kindling fires in the 
 stove. Match heads or 
 lighted kindlings set the 
 clothing on fire. Scarcely 
 a week goes by that you 
 cannot find in the papers an 
 account that some one who 
 used kerosene to kindle the 
 fire was seriously, if not 
 fatally, burned. Kerosene 
 burns so easily it is never 
 safe to use it for starting a 
 fire. Hot stovepipes, the 
 heater itself, or hot air 
 ducts, if close to woodwork, 
 are fire hazards. Ashes are never safe when left loose on 
 the cellar floor, or in wooden receptacles. Metal con- 
 tainers are the only safe ones. 
 
 Miscellaneous sources of fire. All celluloid articles 
 contain oxygen necessary for combustion within them- 
 
 She had used kerosene oil to start her fire 
 432 times without harm. The picture 
 shows what happened on the 433d time. 
 
GASOLINE IS TREACHEROUS 211 
 
 selves. On this account celluloid burns quickly and 
 cannot be extinguished by smothering. Hot air from a 
 register will sometimes ignite celluloid. Make a list of 
 celluloid articles in your home. 
 
 Spontaneous combustion is a frequent cause of disastrous 
 fires. Certain oils, as linseed oil used by painters, absorb 
 oxygen in drying. By this process heat is generated. 
 If the oil is on poor heat conducting materials, as rags and 
 cotton waste, the heat may increase enough to reach the 
 kindling point of the materials and fire results. This 
 usually happens when nobody is around and so the fire 
 makes good headway before it is discovered. 
 
 Experiment. To show how spontaneous combustion takes place. 
 Materials : Carbon disulphide. Phosphorus. Test tubes. Filter paper. 
 Ring stand. 
 
 Method : Dissolve a piece of phosphorus the size of a pea in half a test 
 tube of carbon disulphide. 
 
 ( Note : Do not handle phosphorus with bare fingers. Phosphorus and 
 carbon disulphide are both inflammable.) Wet the filter paper with 
 this solution by rolling it up and inserting it into the test tube. Open 
 the paper and expose it to the air on a ring stand. As the carbon 
 disulphide evaporates the phosphorus oxidizes and generates heat. 
 
 Observation and Conclusion : What happens ? Was heat generated faster 
 than it could be carried off? Explain just how the fire occurred. 
 
 Burning fat or oils used for frying on the stove are not 
 serious dangers as they can be smothered easily with a 
 cover or a heavy rug. Trying to carry the burning fat 
 to the sink is dangerous. A few drops spilled may set fire 
 to other things. The addition of water will scatter the 
 burning drops and spread the fire. 
 
 Gasoline is treacherous. It is a safe rule never to clean 
 with gasoline indoors, and never keep gasoline in a glass 
 bottle. There are other liquids easily obtainable which 
 
212 FIRE PREVENTION IN THE HOME 
 
 will not burn, but which will clean just as well as gasoline. 
 These can be bought at the drug store. They are safe. 
 Use them. 
 
 Extinguishing fires. Since a fire requires oxygen, 
 fuel, and a temperature above the kindling point, if you 
 deprive a fire of any one of these three, it will be extin- 
 guished. There are, then, three possible ways to put out 
 a fire : by smothering, by removing the fuel, and by 
 cooling. 
 
 Smothering. Smothering is the process of keeping oxy- 
 gen of the air away from the burning substance. With 
 the exception of a few substances smothering is an effec- 
 tive way of extinguishing a small fire. A woolen blanket, 
 rug, or coat is better than one made of cotton because it 
 is less inflammable. The blanket is much more effective 
 wet than dry, but it may be used dry. Another way to 
 smother a flame is by setting free a non-combustible gas 
 about the flame which will push the air away and ex- 
 tinguish the fire. This is sometimes done with the follow- 
 ing chemicals : carbon dioxide, ammonia, carbon tetra- 
 chloride, and water in the form of steam. Substances 
 like celluloid, and explosives which contain sufficient 
 oxygen for combustion, cannot be extinguished in this 
 way. 
 
 Removing fuel. It is often possible to remove the 
 combustible material from the vicinity of the flame and 
 thus extinguish it in a short time. Covering combustible 
 material by banking with sand and trenching to remove 
 fuel are practiced in brush and grass fires. Back firing in 
 forest fires utilizes the principle of fuel removal, as does the 
 dynamiting of buildings in the path of the fire in a large 
 city conflagration. ^ 
 
THE HAND CHEMICAL EXTINGUISHERS 213 
 
 Cooling. Water is the most universal fire extin- 
 guisher. It has many properties which favor its use. 
 It can be thrown long distances in a steady stream. 
 It is non-combustible. One pound of it has greater 
 cooling effect than the same weight of any other sub- 
 
 water, our best fire extinguisher. 
 
 stance. On changing to steam it increases 1700 times 
 in volume. The change from liquid to steam absorbs a 
 large amount of heat, thus adding to its value as a cool- 
 ing agent. The steam also tends to smother the fire by 
 excluding air. 
 
 The hand chemical extinguishers. The carbon tetra- 
 chloride and the carbon dioxide extinguishers are two types 
 
214 FIRE PREVENTION IN THE HOME 
 
 of chemical extinguishers suitable for use in the house, 
 the school, and the shop when the fire is small. 
 
 Experiment. How to extinguish (a) burning fat; (b) burning gasoline. 
 
 Materials: Lard. Gasoline. Evaporating dish. Ring stand. Heavy 
 
 cloth. Carbon tetrachloride. Test tubes. 
 
 Method and Results : (a) Heat a teaspoonf ul of lard in an evaporating dish. 
 When smoking hot let two or three drops of water fall into it. Would 
 water be a good substance to extinguish burning fat? Wet the cloth 
 and carefully lay it over a dish of burning fat, excluding all air. 
 
 (&) Pour a tablespoonful of gasoline into the small evaporating dish. 
 Set it on fire. Pour water from the test tube into it. Is the fire 
 extinguished? Smother with a cloth. Pour this out and use another 
 tablespoonful of gasoline. Set it on fire. Pour carbon tetrachloride 
 into it from a test tube. Result? 
 
 (N.ote: Carbon tetrachloride is non-inflammable and evaporates as 
 easily as gasoline.) 
 
 Conclusion: What advice would you give for extinguishing burning fats 
 and gasoline ? 
 
 The carbon tetrachloride extinguisher holds about a pint 
 of volatile liquid in a small container to which a force 
 pump is attached. When the container is opened and the 
 pump worked, a stream of liquid may be thrown upon a 
 near-by blaze. The liquid changes to gas, which smothers 
 the flame. When this extinguisher is used take care not 
 to breath the fumes given off for they are harmful and in 
 a number of instances have proved fatal. This type 
 of extinguisher is particularly valuable for extinguishing 
 small gasoline and oil fires. Water cannot be used for 
 these fires since the oil or gasoline would rise to the surface 
 of the water and continue to burn. 
 
 The small carbon dioxide extinguisher holds 2\ gallons 
 of water, in which are dissolved i^ pounds of baking soda 
 and a bottle containing 4 oz. of strong sulphuric acid is 
 suspended above the solution. When the extinguisher 
 
SAFETY FIRST 
 
 2I S 
 
 is inverted, the acid mixes with the soda and produces 
 carbon dioxide gas. The gas is confined and creates 
 such great pressure that the liquid is forced out the hose 
 to a distance of 40 to 50 feet. The water which escapes 
 is charged with carbon dioxide and 
 has some soda in it. All these sub- 
 stances are good fire extinguishers. 
 The flow of liquid may be stopped at 
 any instant by inverting the extin- 
 guisher. But after once inverting, it 
 must be recharged at once. This is 
 the kind of extinguisher for the house, 
 since the suffocating gas is less than 
 in case of the volatile gas extin- 
 guisher which is used in the garage. 
 
 Safety first. If you get caught in 
 a burning building and the fire has 
 made such headway as to be a serious 
 menace to you, it is your first duty 
 to save your life. It is well to be 
 prepared for any emergency and to 
 know in advance just what to do. 
 Do you know where the stairs are? 
 The fire escapes? If it is necessary Section of a carbon dioxide 
 
 .-i i i f-,1 i extinguisher. 
 
 to pass through a smoke-filled room, 
 tie a wet cloth over the nose and mouth to absorb the 
 smoke and crawl on the floor as there is less smoke near 
 the floor. If you think you must jump from a window, 
 throw out pillows, cushions, and mattress to land on 
 and jump only if forced to it. Bed clothing may be tied 
 into a rope on which to climb to safety. Above all keep 
 cool. 
 
2l6 FIRE PREVENTION IN THE HOME 
 
 Scoring fire hazards. Score your fire hazards rigidly 
 and then go carefully over your list to see what changes 
 
 you can make at once 
 to improve conditions. 
 If the matter is outside 
 your own control talk it 
 over with other people 
 and get their advice as 
 to how best to do away 
 with the hazard. We 
 should all work together 
 
 The best air in a burning house is near the floor. t() prevent unne cessary 
 
 fires. A rather different score card could be made by boys 
 and girls living in small rural communities or in farming 
 or lumbering sections. If you live under such conditions 
 try to make a score card to fit your conditions. 
 
 THOUGHT QUESTIONS 
 
 1. Suppose you were visiting and were awakened in the night by 
 the cry of " Fire " and could smell the smoke. What are some of 
 the different conditions you ought to be able to meet? Tell just 
 what you would do under these different conditions. 
 
 2. How is it that " fireproof " buildings are sometimes destroyed 
 by fire? 
 
 3. Prepare to debate one side of this question. Resolved : That the 
 use of kerosene in the home is a greater fire hazard than the use of gas. 
 
 4. Make out a set of rules needed in your home to remove some 
 of the present fire risk practices. 
 
 5. Give as many reasons as you can why, considering all the harm 
 fire does, the world is better off with it than it would be without it. " 
 
 6. Plan a " fire drill " for the home. Assign a particular thing for 
 each member of the family to do, as : giving the alarm, trying to ex- 
 tinguish the fire, saving things of value. Try it out by giving the 
 alarm unexpectedly. 
 
SCORE CARD 217 
 
 SCORE CARD. FIRE-HAZARD SURVEY OF MY HOUSE 
 
 SCORE 
 
 Perfect Allowed 
 
 Fireproof constructions 
 Slate or other fireproof roof 
 Stone, brick, or concrete walls 
 
 2. Not nearer than 25 ft. to other wooden 
 
 buildings 5 
 
 3. Metal ash cans used 
 
 Gas connections of metal pipe, not of rub- 
 ber . 25 _ 5 
 
 4. Matches 
 
 Safety matches used 
 
 Out of reach of children i\ 5 
 
 5. (a) No swinging gas jets or lamp brackets 
 
 near curtains. 
 
 Oil lamps of metal, low, not easily 
 upset (5). Score either (a) or (b) . . 5 
 
 6. No one in family is careless with fire 
 
 No smokers in family .. .,-.... '2\ 5 
 
 7. No stove pipe through wall or floor . . 2 
 No stove within one foot of unprotected 
 
 wall 1 1 
 
 Metal or asbestos mat under stove and ex- 
 tending 10 in. in front i \ 5 
 
 8. No gasoline kept in glass bottle . .' 
 No gasoline used for cleaning indoors 
 
 Kerosene never used in kindling fire . . 2 5 
 
 9. No rubbish allowed to collect 2 
 
 No oily rags collect or left \\ 
 
 No celluloid articles in house \\ 5 
 
 Have a hand fire extinguisher .... 2 
 Fire engine house within \ mile .... 2 
 Hydrant within 300 ft. of house .... 
 Fire alarm box within 500 ft. or have a 
 telephone % 5 
 
 TOTAL : 50 
 
218 FIRE PREVENTION IN THE HOME 
 
 REFERENCE BOOKS 
 
 Adams, Harper's Outdoor Book, pages 191-200 (Fire engines). Harper and 
 
 Brothers. 
 Circular 75. Safety for the Household, U. S. Bureau of Standards : good account of 
 
 fire hazards and treatment of injured. 
 Croker, Fighting Fire. Dodd, Mead and Company. 
 Hill, Fighting a Fire. The Century Company. 
 Moffett, Careers of Danger and Daring, pages 200-256 (Life of firemen). The 
 
 Century Company. 
 Report U. S. G. S. for IQOQ: data and comparisons on the amount of fire damage 
 
 done in the U. S. 
 
 Reports from State Fire Marshal: in most states. 
 Richman and Wallach, Good Citizenship. American Book Company. 
 Safeguarding the Home against Fire: A pamphlet, 91 pp. By National Board of 
 
 Fire Underwriters : very complete account of causes of fires, how to guard 
 
 against them, and what to do in emergencies. 
 Warren, Stories from English History, pages 303-307 (Great fires). D. C. Heath 
 
 and Company. 
 
 Weeks, Avoidance of Fires. D. C. Heath and Company. 
 Whitman, Fire Hazards and Safeguards: Ten Lessons. General Science Quarterly. 
 
 March, 1920. 
 
CHAPTER XIV 
 CLOTHING AND ITS USES 
 
 Problems. i. To understand How the temperature of 
 the body is regulated. 
 
 2. To learn what is proper clothing for our bodies and 
 feet. 
 
 3. To see of what our clothes are made. 
 
 4. How can we detect fraudulent materials in cloth- 
 ing? 
 
 5. To see how clothing is cleaned. 
 
 Experiments. i. To distinguish wool from cotton by the burning test. 
 
 2. To show the effect of chemical reagents on different fibers. 
 
 3. Removal of spots and stains. 
 
 Project I. To FIND OUT OF WHAT MATERIALS CLOTHES ARE MADE. 
 
 1. Find out how to make various, chemical tests for different 
 kinds of fibers. 
 
 2. Find out some of the characteristic physical properties, in- 
 cluding examination under the microscope if possible. 
 
 3. Practice in applying tests to poor materials. 
 
 4. Practice in applying tests to known mixtures. 
 
 5. Use of tests in determination of mked goods, or for adultera- 
 tion, filling, etc. 
 
 6. Common fibers for testing: cotton, mercerized cotton, linen, 
 wool, silk, artificial silk. 
 
 7. Apply tests to determine composition of various articles of 
 clothing worn, if samples for testing can be obtained. 
 
 219 
 
220 
 
 CLOTHING AND ITS USES 
 
 HAIR. 
 
 8. Your report : Make diagrams of fibers seen under microscope. 
 Give an account of all testing work. 
 Mount specimens of original and tested cloth. 
 Conclusion regarding adulteration. 
 
 Suggested Projects. 
 
 1. TO PREPARE A TABLE TO SHOW HOW TO REMOVE SPOTS AND 
 STAINS FROM DIFFERENT KINDS OF CLOTH. 
 
 2. TO MAKE SOAP FROM HOUSEHOLD GREASE. 
 
 The skin regulates our body temperature . We are all 
 aware of the fact that sometimes we feel hot or feel cold, 
 
 but if we were to take 
 the body temperature at 
 either of these times, we 
 would find it varied little 
 from its normal heat of 
 98.6 degrees. To be sure, 
 the outer part of the 
 skin would be colder on a 
 cold day and warmer on 
 a warm day, but the skin 
 itself has a very com- 
 plex mechanism for regu- 
 lating our body temperature. By means of the sweat 
 glands shown in the diagram as little coiled tubes, and the 
 very delicate nervous apparatus which we need not now 
 try to understand, the skin is enabled to regulate the heat 
 of the body. When we do more work and the body be- 
 comes warmer from the increased oxidation within it, the 
 skin automatically is enabled to throw off this heat and it 
 is able also to retain more heat on a cold day. 
 
 How the body loses heat. Heat is lost from the body 
 by the three methods we have studied in the preceding 
 
 A section through the skin. 
 
HOW THE BODY LOSES HEAT 
 
 221 
 
 chapters. A certain amount of heat is lost by conduc- 
 tion, although the air is a very poor conductor, and warm 
 fabrics get much of their heat-holding qualities because of 
 the stagnant air confined in their meshes. Most of our 
 heat from the body is lost by convection. When we 
 fan ourselves, we create a current of air, causing cooler air 
 to replace the 
 warm air about 
 the body. We 
 also lose heat 
 by radiation to 
 other solid ob- 
 jects which are 
 cold. It is very 
 easy to take cold 
 by sitting on the 
 damp ground, or 
 
 close to cold 
 windows or 
 walls, because in 
 this way warmth 
 is removed rap- 
 idly from one 
 part of the body. 
 
 Which side of this boy will lose more heat ? Why ? 
 
 Curiously enough, although we feel warm when we per- 
 spire, yet much of the heat of the body is taken away 
 by evaporation of the water from the body surface. On 
 a hot muggy day when the atmosphere about us is moist, 
 little heat is lost by evaporation and we feel much hotter 
 than on an equally hot dry day when we perspire freely. 
 A person may feel the heat far more in New York on 
 a day in August than in the jungles of British Guiana at 
 
222 
 
 CLOTHING AND ITS USES 
 
 the same time of year, because in the tropics the trade 
 winds cause rapid evaporation of the moisture from the 
 body. On a humid day a blanket of stagnant heated 
 air forms about the body, which makes one feel very un- 
 comfortable. For this reason electric fans and the punkas 
 of India have saved people from much discomfort by 
 keeping the air in motion, thus evaporating the moisture, 
 and removing heat from the body. 
 
 Bathing and the skin. Since the skin is such an im- 
 portant organ for heat regulation and for getting rid of 
 wastes as well, it goes without saying that we should take 
 good care of it. Bathing keeps the pores open and the 
 
 skin clean. In summer, when 
 perspiration is increased, 
 baths should be more fre- 
 quent than in winter. A cold 
 shower or plunge every day, 
 both in winter and in summer, 
 is an excellent habit to accus- 
 tom the skin to different 
 changes. If you find that 
 after a rubdown the skin 
 does not glow and you feel 
 cold and chilly, do not take 
 the baths so cold. It is al- 
 ways well to begin with 
 tepid water and gradually turn on colder as the bath pro- 
 gresses. Hot baths should be taken only at night, as they 
 tend to bring blood to the skin and increase the radia- 
 tion. When we chill the body, the body resistance is 
 lowered and germs, which are almost always present in our 
 mouths and throats, develop rapidly and cause a cold. 
 
 The blood is brought to the surface of the 
 body and there loses some of its heat 
 through the skin. 
 
HOW TO WEAR CLOTHING 
 
 223 
 
 Underclothes and their uses. In winter we need under- 
 clothes which are non-conductors of heat, and retain the 
 warmth in the body. In summer we need underclothes 
 that do not hold moisture, for wet, clammy underclothes 
 cool us by conduction if it is cold, or if it is warm, 
 make us uncomfortably hot by preventing evaporation, 
 and sometimes even cause a cold to develop. It does 
 not seem to make very much difference what kind of 
 materials are used, whether 
 woolen, cotton, linen, or silk 
 fiber, so long as the under- 
 clothes are porous. Woolen 
 underclothes are best for wear 
 in winter, because the natural 
 curly fiber makes them porous, 
 and also because they absorb 
 more water, and this protects 
 the skin from cooling too rap- 
 idly in case we get overheated. 
 Most colds are taken because 
 people insist on wearing too 
 much in winter. They wear heavy underclothes and heavy 
 outer clothes, then go from a warm room to the cold out- 
 doors, and back again to warm workrooms where the 
 temperature is often higher than that of summer heat. 
 The better rule is to wear a medium weight underwear in 
 winter and heavier outside clothes, which can be changed 
 as one goes into different temperatures. 
 
 How to wear clothing. The chief use for clothing is 
 to keep heat in the body, although some people think, 
 as in the case of some animals which wear their fur and 
 feathers for attraction, that " fine feathers make fine 
 
 Mesh in underwear. 
 
224 
 
 CLOTHING AND ITS USES 
 
 birds." Heat does not easily escape through dry air, 
 and clothing prevents its escape by holding air in little 
 pores of the cloth. Fur of animals, a natural covering, 
 is very warm, yet averages in the case of many animals 
 about 98 per cent air and only two per cent hair. The 
 outer clothes, both of boys and girls, should not be very 
 tight fitting, and not too heavy, especially if heavy under- 
 clothing is worn. Tight-fitting clothes interfere with the 
 circulation of the blood and are not hygienic. Clothing 
 should therefore be loose and the weight distributed as 
 nearly equal as possible on all parts of the body. Get the 
 habit of wearing an overcoat, and take it off when you go 
 into the house. Learn to wear different weights of clothes 
 according to the temperature, keeping lightweight and 
 more porous ones for the hot weather. If you get wet, 
 do not sit around in wet clothes. 
 
 Care of the feet. It is very important to remember 
 to keep the feet dry. Wet feet are one of the most 
 
 common causes of colds. 
 
 For ordinary wear, 
 heavy-soled shoes may 
 keep the feet fairly 
 dry, but in case of rain, 
 it is better to wear rub- 
 bers, although most 
 people consider them 
 a nuisance. Our feet 
 surely should receive 
 our best care, for they bear our body weight the greater part 
 of the working day. They, are often harmed in youth by 
 shoes, especially in the case of girls, who pride themselves 
 on the shapely appearance of the feet and ankles. The 
 
 A great help in preventing a cold. 
 
WHERE OUR CLOTHES COME FROM 
 
 225 
 
 high heels worn by many do much to strain the muscles 
 of the feet, and are responsible for many aches and pains 
 in later life, which come as a result of flat feet, broken 
 arches, and other ailments. Corns, callous spots, and 
 blisters are caused by wearing shoes of a wrong size or 
 shape for the feet. Shoes should be long and broad enough 
 to give plenty of room for the toes. They should have a 
 
 Notice how the high heel brings the body support hi front of the heel, causing 
 an unnatural arching of the bones. 
 
 straight last, and the heels should not be too high. A 
 common sense shoe, sold by most dealers now-a-days, is 
 better than the longer, pointed, high-heeled shoe which is 
 fashionable and worn by girls who do not realize the harm 
 caused by wearing a shoe which does not fit the shape of 
 the foot. 
 
 Where do our clothes come from ? Most boys and girls 
 would answer this question by saying that their clothing 
 came from the store, but if they stop to think they will 
 realize that animals have a covering of either fur or hide 
 and that man, too, uses these materials for body covering. 
 Long years ago when primitive man lived on the earth, 
 he covered himself with skins which were taken from the 
 animals he killed. To-day we use these same skins, but 
 
 H.-WHIT. CIV. SCI. IN THE HOME 15 
 
226 
 
 CLOTHING AND ITS USES 
 
 after a process of curing and softening they are manufac- 
 tured into shoes, gloves, and other useful articles. We 
 have gone much further than primitive man in the mak- 
 ing of clothes, for we have come to use parts of plants as 
 well as the wool and other materials taken from animals. 
 The cotton plant, linen, from flax, and other fibers such 
 
 Sheep are a great asset to the wealth of our nation. 
 
 as jute, hemp, ramie, and yucca, as well as that most 
 beautiful fabric of all, silk, which is taken from the 
 cocoon of the silkworm, have all been put to man's best 
 uses. 
 
 Wool. Prehistoric man domesticated sheep because 
 he found he could use them for food and the skins for 
 clothes. Later the wool was carded, spun, and woven by 
 hand. Our woolen materials are woven in factories. The 
 
COTTON 
 
 227 
 
 woolen fibers vary from about an inch to eight or nine 
 inches in length. The long fibers are woven into fine 
 woolen cloths, while the short, coarse ones make some 
 kinds of worsted goods. These fibers are covered with 
 
 little projecting 
 scales, which cause 
 them to cling to- 
 gether, and this 
 gives the cloth its 
 characteristic woolly 
 or felted appearance 
 and produces a po- 
 rous fabric which, as 
 we have seen before, 
 holds air and retains 
 heat. 
 
 Cotton. Our 
 Southern states in 
 the past produced 
 most of the cotton 
 used, but to-day cot- 
 ton is grown in many 
 other warm countries, especially in Egypt. The cotton 
 fiber is really a product of the flower, for as the seeds are 
 formed in the pod, this fiber grows around them as a pro- 
 tection, and consequently the seeds must be removed,. 
 
 Plant bearing cotton ready to pick, showing the boll 
 or fruit containing seeds surrounded by cotton 
 fibers. (Museum of Natural History.) 
 
228 
 
 CLOTHING AND ITS USES 
 
 this being done by a process known as ginning. Cotton 
 fibers are smaller than woolen, and under the microscope, 
 have a twisted appearance. This twisting helps in the 
 manufacture of cotton cloth. Cotton fiber contains fewer 
 
 air spaces than woolen, 
 and therefore cotton 
 cloth is cooler. 
 
 Experiment. To distinguish 
 wool from cotton by the 
 "burning test." 
 
 Materials: Cotton and wool 
 string. Forceps. Burner. 
 
 Method: Set on 'fire a string 
 of cotton and one of wool 
 at the same time. 
 
 Observation and Conclusion : 
 Which burns more 
 rapidly? Which burns 
 with more flame? Ob- 
 serve the odor from each. 
 Tell how to distinguish 
 cotton from wool by the 
 " burning test." 
 
 Linen, Flax, a little 
 plant with a well-known 
 blue flower, produces all 
 of our linen. The fiber 
 comes from the stems, 
 which have to be rotted 
 under water, beaten to 
 remove the woody tissue, spun and woven into cloth. 
 This industry formed a very considerable place in the lives 
 of the Belgians, French, and Russians who lived in the area 
 devastated by the World War. The present high price 
 of linen is due very largely to the destruction by the 
 
 Flax grown for fiber. 
 
SILK 
 
 229 
 
 Huns of fields of flax and especially the linen factories in 
 Belgium. Flax is not an abundant plant in this country, 
 and linen is harder to manufacture than cotton ; hence it 
 is more expensive. Linen is stiff, washes readily, and makes 
 up the greater part of our table linen, collars, and cuffs. 
 
 Silkworm, cocoons, chrysalis, moth, and skein of silk. (After Weed ) 
 
 Silk. Silk is one of the smoothest and most beauti- 
 ful cloths we have, as well as a good conductor of heat. 
 The moth which produces the silkworm passes through 
 four stages, like fleas, mosquitoes, and many other insects. 
 The eggs are laid by the mother moth on the mulberry 
 
230 
 
 CLOTHING AND ITS USES 
 
 leaves which are the food of the little rapidly growing 
 caterpillars. They shed their coats as they become 
 larger, but after a time they become quiet, shrink a little 
 in size, and spin a wonderful covering of silk. The silk is 
 made within the body of the caterpillar, and is given out 
 
 Sorting the cocoons of the silkworm, in Japan. 
 
 from just below the mouth, in the form of a jelly-like 
 material. This hardens rapidly into a yellow or whitish 
 thread. The process of weaving a cocoon takes from two 
 to three days. The cocoons are gathered, and after plac- 
 ing in hot water, the silk is reeled off, very largely by 
 hand. It takes between two and three thousand cocoons 
 to make a pound of silk. Most of the labor is done by 
 
DETECTION OF FRAUDS 
 
 231 
 
 hand, hence silk making must go on in countries like 
 Japan and China, where wages are low. 
 
 Detection of frauds in clothing. We all know that 
 woolen cloth frequently contains much cotton. We are 
 often sold mercerized cotton, or artificial silk, which is 
 made by chemical means from various vegetable wastes, 
 and it is worth while to know some simple means for 
 detecting these frauds. If one has a microscope, it is 
 
 (a) Cotton. 
 
 (c) Silk. 
 
 very simple to recognize by examination the fiber of silk, 
 cotton, linen, and woolen fabrics. (See illustration.) Some 
 easy tests which can be made at home are the following: 
 If we place silk fibers in hydrochloric acid, they will dis- 
 solve. By boiling wool in caustic soda for five minutes, 
 the wool dissolves. Thus it is very easy to find out 
 whether wool and silk are mixed with other substances 
 in cloth. Linen threads are much stronger than cotton. 
 A very easy way to tell linen from cotton is to place in 
 olive oil for five minutes ; if linen, the material becomes 
 translucent; if cotton, it remains unchanged. 
 
 Experiment. To show the effect of chemical reagents on different fabrics. 
 Materials: Pieces of cotton cloth, wool, and silk of known purity. Test 
 tubes. Beakers. Burner. Hydrochloric acid. Sodium hydroxide. 
 Ammonia. Borax. Washing soda. Nitric acid. Sulphuric acid. 
 
232 
 
 CLOTHING AND ITS USES 
 
 Method and Results : (a) Shrinking lest. Measure pieces of cotton cloth and 
 woolen cloth. Pour boiling water upon them and leave overnight. Dry 
 without stretching. When dry measure again. Is there any shrinkage ? 
 
 (&) Test the solubility of cotton, woolen, and silk cloth in each of the 
 following : 
 
 i. Cold concentrated hydrochloric acid. 2. Hot concentrated hydro- 
 chloric acid. 3. Cold diluted hydrochloric acid. 4. Hot diluted hydro- 
 chloric acid. 5. Make similar tests with concentrated and dilute nitric 
 acid, and concentrated and dilute sulphuric acid, both cold and hot. 
 Also make tests with cold and hot concentrated and dilute solu- 
 tions of sodium hydroxide, ammonia, borax, and washing soda. 
 Note any changes while the cloth is in the solution. Rinse and dry. 
 Are any other changes observed? Be very careful not to get any of 
 these solutions on your clothes or hands. 
 
 Application: What precautions should be taken in washing clothing? 
 Can chemicals be used in finding out how much wool or other fiber 
 there is in a certain piece of cloth? Explain. 
 
 Care of the clothes. Clothes are to be worn both for 
 comfort and for looks. All girls like to look attractive, 
 
 but not always so with boys. 
 How many boys have lost a 
 good job just because of dirty 
 collars and shirts, or carelessly 
 blacked shoes. We may have 
 our clothes neat and clean, 
 even if they are not new. 
 Underclothes should be fre- 
 quently changed and washed, 
 especially in hot weather, as 
 they absorb the perspiration 
 and body wastes. We should 
 
 be particular about changing socks and stockings fre- 
 quently, and washing the feet often as well. 
 
 How to clean clothes. We know that in order to take 
 out soluble substances from clothes which have become 
 
USE OF SOAP 233 
 
 dirty, we must use plenty of soap and water. This water 
 must be soft, because hard water (which has certain min- 
 eral substances dissolved in it) will not always do its 
 work, even if soap is used. It is usually better to soak 
 the clothes in cold water first to loosen the dirt, and later 
 to wash in hot water. Boiling water should not be used 
 in washing woolen goods as it renders them less porous 
 and therefore not so warm. Alkaline soaps and other 
 alkalies should not be used in washing woolens because 
 alkalies dissolve wool. 
 
 Bleaching. Sometimes we may bleach out the stains 
 after having placed the clothing in the water, and for 
 this purpose, nature's own ways, sunlight and the oxygen 
 of the air, are useful, although bleaching substances, 
 such as Javelle water, lemon juice, cream of tartar, and 
 other substances are used. A good home project would 
 be to find out the properties of some of the bleaching agents 
 mentioned, and some others sold in stores. In Javelle 
 water and in most household bleaching agents, the substance 
 which does the bleaching is chlorine, which forms the base of 
 some of the poison gases which have done such terrible 
 havoc on the battle fields of the World War. Chlorine 
 or bleaching powder must not be used in bleaching wool and 
 silk because it stains them yellow. 
 
 Use of soap. We have all heard of the days when 
 our great-grandmothers made soft soap by placing to- 
 gether scraps of fat, butter, tallow candles, and the like, 
 and melting them down with a strong solution of lye, 
 which was made by treating wood ashes with lime. Now 
 hard soap is made by the addition of certain other sub- 
 stances and it has become a necessity of our lives. Soap is 
 a solvent which breaks grease up into tiny particles, form- 
 
234 CLOTHING AND ITS USES 
 
 ing an emulsion, and in this condition it is carried off in 
 the water from our hands and substances on which it is 
 placed. The Germans during the late 
 war suffered greatly from the lack of 
 soap. 
 
 Washing powders and their use. - 
 When water is hard or contains mineral 
 substances, such as lime or magnesium, 
 soap cannot well be used. It is less 
 
 An emulsion seen under Wasteful of SOap if SUch Waters are first 
 the microscope. . . 
 
 softened by the addition of washing 
 powders. These usually have washing soda as a base, which 
 combines chemically with the lime in the water, changing it 
 to an insoluble form, so that it does not affect the soap. 
 Washing powders should be dissolved in a tub of water 
 before the clothes are put in. 
 
 Neutralization. Dirt and some stains are removed 
 from materials, as we have seen, by solution and by 
 bleaching. Other stains can be removed by a process 
 known as neutralization. Vinegar and many fruit juices 
 have a sour taste and will turn a piece of blue litmus 
 paper red. A similar color change occurs when blue 
 litmus paper is placed in the presence of any diluted acid, 
 such as nitric or sulphuric. This is a test for acids. Other 
 substances which have a bitter taste and a soapy feeling 
 are called bases. Lye in soap is a strong base, as is soda, 
 also. We find that if bases are tested with red litmus 
 paper, it turns blue. We therefore have an artificial test 
 for acids and bases. If we now add to a solution con- 
 taining a base some acid drop by drop, and keep testing 
 with red litmus paper, we find at length that the com- 
 bination of acid and base does not affect the paper. Neither 
 
REMOVAL OF GREASE 235 
 
 red litmus paper turns blue, nor blue paper red, in the 
 presence of this combination. Such a mixture as this is 
 said to be neutral. In cleaning we make use of neutral- 
 ization, by using acids to remove stains caused by bases, 
 and by using bases to remove stains caused by acids. 
 
 Experiment. Removal of spots and stains. 
 
 Materials: Strips of white cotton cloth. Congo red solution. Sodium 
 carbonate. Lemon. Ammonia. Acetic acid or white vinegar. 
 Salad oil. Lard. Butter. Alcohol. Gasoline. Carbon tetrachlo- 
 ride. Oxalic acid. Black ink. Red ink. Test tubes. 
 
 Adds and alkalies: Dye one strip of white cloth in Congo red. A sec- 
 ond in Congo red to* which is added a pinch of sodium carbonate. 
 Dry them. What are the colors? 
 
 Let a drop of lemon juice (an acid) fall on the blue cloth. Result. 
 Try to restore the color with ammonia. Let a drop of ammonia fall 
 on the red cloth. Result. Try to restore the color with acetic acid 
 or vinegar. 
 
 Acids and alkalies have opposite properties and each tends to 
 destroy the other. 
 
 Grease spots: Dirt held by oil or grease can only be removed by the 
 removal of the oil or grease. Test the solubility of salad oil, lard, 
 and butter in water, alcohol, gasoline, carbon tetrachloride. Results? 
 Suggest a good way to remove grease spots from clothing. What 
 danger is there in using gasoline? 
 
 Fruit and ink stains : Try cold water, then hot water. Oxalic acid will 
 remove black ink containing iron. White cotton or linen may be 
 treated with Javelle water. The cloth must be thoroughly washed 
 in dilute ammonia afterwards. 
 
 NOTE : Use alcohol for grass stains ; dilute hydrochloric acid for 
 
 . rust ; turpentine for paint ; benzole for tar, and sulphurous acid or 
 hydrogen peroxide for bleaching white woolens, silks, and linens. 
 
 Removal of grease. An easy way to remove grease 
 from clothing is to cover the grease spot with blotting 
 paper and press with a hot iron. The grease is melted 
 by the heat and absorbed by the blotter, which draws the 
 liquid up into it by capillary attraction. Grease and oils 
 
236 CLOTHING AND ITS USES 
 
 may also be absorbed by French chalk, or a mixture oi 
 starch and gasoline. Tar can often be removed by cov- 
 ering the substance first with lard, then heating this for 
 some time and washing. 
 
 An interesting home project would be to make a series 
 of experiments to determine what methods were best 
 fitted to remove different stains from clothes. Why not 
 try this? 
 
 Use of the score card. This is a very important per- 
 sonal card and should be scored with great care. Your 
 total score only need be given in class or in your notebook. 
 Try to improve at once in matters where your score is 
 low. In some of the personal matters you surely can do 
 this. Score again in a month to see how much you have 
 improved. 
 
 REFERENCE BOOKS 
 
 Allen, Asia (Chapters on Silk Production). Ginn and Company. 
 
 Allen, Europe (Chapters on Flax and Silk). Ginn and Company. 
 
 Bassett, The Story of Wool. Perm Publishing Company. 
 
 Brownell, General Science, Chapter IX. P. Blakiston's Son and Company. 
 
 Buchanan, Great Inventors and Their Inventions (Eli Whitney and the Cotton Gin). 
 American Book Company. 
 
 Carpenter, How the World is Clothed. American Book Company. 
 
 Clark, An Introduction to Science, Chapters XI, XV. American Book Company. 
 
 From Wool to Cloth. American Woolen Company, Boston. (Free) 
 
 Fall, Science for Beginners, Chapter XIII. World Book Company. 
 
 Gannett, Commercial Geography. American Book Company. 
 
 Hunter, A Civic Biology, Chapters X, XV. American Book Company. 
 
 Sargent, Plants and Their Uses. Henry Holt and Company. 
 
 Bddmer, The Book of Wonders (Story of Cotton, Wool, and Silk). Presbrey Syn- 
 dicate, N. Y. 
 
 Toothaker, Commercial Raw Materials. Ginn and Company. 
 
 Turner, The Study of Fabrics. Appleton and Company. 
 
 Van Buskirk and Smith, The Science of Everyday Life, Project XIV. Houghton 
 Mifflin Company. 
 
 Weed, Chemistry in the Home. American Book Company. 
 
SCORE CARD 
 
 237 
 
 SCORE CARD. CLOTHING, BATHING, VENTILATION 
 
 
 
 SCORE 
 
 
 
 PER- 
 
 MY i 
 
 SCORE 
 
 
 SCORE 
 
 
 Total 
 
 Outer clothes 
 Clothes 
 fit well but loosely worn 
 sensible in color and pattern 
 well washed and mended 
 
 2 
 2 
 2 
 
 
 
 
 Collar and shoes clean .... 
 
 2 
 
 
 
 Shoes sensible width and style 
 
 2 
 
 
 
 
 
 
 
 Underclothes 
 Mesh underwear worn .... 
 
 2 
 
 
 
 Woolen underwear in winter .... . 
 
 2 
 
 
 
 Socks and stockings changed every other day . 
 Underclothes changed every other day in sum- 
 mer, oftener if odor is noticeable .... 
 Wear warmer outer clothes in winter or on going 
 out of doors in cold weather 
 
 2 
 2 
 2 
 
 
 
 Bathing 
 Tub bath weekly : twice a week in summer 
 Feet bathed every other day 
 
 2 
 2 
 
 
 
 Shower or cold rub in morning . 
 
 2 
 
 
 
 Face, neck, and ears washed with soap and water 
 every morning 
 
 2 
 
 
 
 Hands washed before and after meals and after 
 going to toilet ' 
 
 2 
 
 
 
 
 
 
 
 Bedroom hygiene 
 Window space equal to \ floor area . ... 
 Windows screened full length ...... 
 Windows open top and bottom at night or sleep- 
 ing porch 
 
 2 
 2 
 
 
 - 
 
 No hangings 
 
 j 
 
 
 
 No draft on bed . 
 
 I 
 
 
 
 
 
 
 
 Home ventilation 
 Ventilation in every room in house . ... 
 Air seldom seems " close " or " stuffy " . . . 
 Sunlight not kept out by heavy curtains . . 
 House aired thoroughly once a day .... 
 Drafts avoided . , 
 
 2 
 2 
 2 
 2 
 2 
 
 
 
 TOTAL 
 
 CQ 
 
 
 
 
 
 
 
PART IV. LIGHT IN THE HOME 
 
 CHAPTER XV 
 SOURCES OF LIGHT FOR HOME USE 
 
 Problems. i . To understand the importance of light 
 and eyes. 
 
 2. To see what important properties of light we utilize. 
 
 3. To understand how my home is lighted by natural means. 
 
 4. To understand how my home is lighted by artificial 
 means. 
 
 5. To compare the different types of lighting. 
 
 Experiments and demonstrations. i. To show degrees of trans- 
 parency. 
 
 2. To show the advantage of the mantle in gas lighting. 
 
 3. To show how electricity may be changed into light. 
 
 4. To show the advantage of tungsten over carbon lamps. 
 
 Project I. To IMPROVE THE LIGHTING OF MY HOME. 
 
 1. Take up question of quantity of light, natural and artificial, 
 for various kinds of work, and whether other devices would cut 
 down expense of artificial light. 
 
 2. If some room is poorly lighted in daytime, can you devise a 
 remedy ? 
 
 3. What about shades, glare, and harmful habits in the use of 
 light? 
 
 4. Have you a satisfactory switch or button installation for turn- 
 ing lights on and off? Additional lamps needed anywhere? 
 
 238 
 
HOW DOES THE SKY GIVE LIGHT? 239 
 
 Suggested Projects. 
 
 1. MAKE A TOY PERISCOPE. 
 
 2. TO USE A LARGE GLASS AS A MIRROR FOR " STAGE TRICKS." 
 
 See Book of Magic, HOPKINS. 
 
 Light and mankind. Have you ever, while looking 
 out of the window, put your hands over both eyes, and 
 then tried to imagine what life would be without light? 
 What a dismal place the earth would be ! We have come 
 to depend very 
 much upon the sun 
 and its radiant en- 
 ergy, which travels 
 to us across an 
 ether space just as 
 heat does, and our 
 
 homes have been The sun is the source of all energy. 
 
 planned so that we can make use of all sources of light, 
 both natural and artificial. Much of our light comes 
 from the sky rather than directly from the sun. The area 
 of the sky visible from our windows is very important, 
 because it is from this that we get most of our light. The 
 sun at midday is so bright we can look at it only with 
 strongly smoked glasses, and we all enjoy the long twilight 
 of summer following the light of day, when no sun is 
 visible. 
 
 How does the sky give light ? This seems a simple 
 question, but in order to understand how light comes to 
 us, we must first learn some very important properties of 
 light. If we place a lighted candle or lamp on the table, 
 we can all see it. If we hold a piece of window glass in 
 front of it, the glass does not in any way obstruct the light. 
 We call such an object transparent. On the other hand, 
 
240 
 
 LIGHT IN THE HOME 
 
 a piece of oiled paper or ground glass, if placed in front of 
 the candle, allows a certain amount of light to go through, 
 but we cannot see the flame distinctly. Such a sub- 
 stance is called a translucent 
 body. If we now take a board 
 or piece- of sheet metal and hold 
 it before the light, it prevents 
 any light from reaching our eyes. 
 Such a substance is called an 
 opaque body, and behind such a 
 body, the space from which light 
 is excluded is called a shadow. 
 Light passes through transparent 
 bodies without much loss or 
 scattering of the rays. Less 
 light passes through translucent 
 bodies, and there is much scat- 
 tering of the rays of light, while 
 no light at all passes through 
 opaque bodies. 
 
 Which obstructs the most light? 
 Which the least ? 
 
 Experiment. Transparency. 
 
 Hold glass, oiled paper or ground glass, and sheet metal in turn between 
 your eyes and a light. Explain the different effects. 
 
 Reflection and its reasons. If you take a smooth 
 surface, such as a mirror, and allow light to fall on it, a 
 strong beam is reflected, while from a roughened surface 
 no such beam passes, the light being scattered from the 
 irregular surface, or diffused. It has long been known 
 that light striking a flat smpoth surface would be reflected 
 from it at exactly the angle at which it strikes it. If, 
 in a beam of sunlight the rays which travel parallel to each 
 
NATURAL LIGHT IN THE HOME 241 
 
 other strike a roughened surface, they are thrown off in 
 different directions and produce diffused light. 
 
 Light from the sky. We are now better able to under- 
 stand why we get light from the sky. The air always 
 contains particles of solid and liquid material, as dust, 
 and moisture. It is very seldom that the air is clean, and 
 then only at points far above the earth, and even in this 
 air there are enough of these dust particles to divert the 
 
 Which surface diffuses light ? 
 
 rays of light from the sun. Since the surfaces of these 
 particles are irregular, the light is diffused in all direc- 
 tions. Thus it is that particles in the air above our homes, 
 receiving sunlight, divert some of these rays to us, no 
 matter where we may be situated. If there were neither 
 air nor any other substance about the earth, then the sky 
 would appear dark, and we would only get light directly 
 from the sun, the moon, and other bodies in the heavens, 
 the stars and the planets. 
 
 Natural light in the home. Fortunate is the boy or 
 girl who lives in a detached house, for direct sunlight 
 bathes the house on bright days, and some of it is sure to 
 enter. Within the crowded city with its tall buildings 
 standing close together, with one home piled on top of 
 another, as we have in apartments, people are fortunate 
 if they get direct light in more than one or two rooms, and 
 
 H.-WHIT. CIV. SCI. IN THE HOME 1 6 
 
242 LIGHT IN THE HOME 
 
 in many city homes no direct light enters at all. Light 
 is of much importance to us, not only because we see ob- 
 jects by the light which comes from them, but also be- 
 cause it benefits health, and destroys bacteria. We must 
 also remember, if we live in the country, that too much 
 shade and too many trees are as bad as too few. Trees, 
 
 A house with plenty of light. 
 
 hills; and buildings, as well as porches and other overhang- 
 ing parts of the house, all cut off light from our houses. 
 
 Regulation of sunlight in the home. It is a very good 
 rule in planning a house to have the window space of a 
 room one fourth to one fifth of its floor space. This will 
 give a sufficient amount of light for most purposes. The 
 bedroom may have less window space, but no bedroom 
 should ever shut out light and air by having window hang- 
 ings and draperies. If the wall paper and woodwork 
 of the room are dark, the room itself will be dark, for dark 
 objects absorb light. As a rule the ceiling should be 
 lightest, the walls a little darker, and the floor still darker. 
 
ARTIFICIAL LIGHT IN OUR HOMES 
 
 243 
 
 This gives good distribution of light within the room. If a 
 room is too light, and at the same time too hot in summer, 
 we can adjust the amount of light entering by means of 
 blinds or awnings. The Venetian blind or porch shade is 
 a convenient type to 
 use, for it shuts out 
 the sun's rays with- 
 out preventing a cir- 
 culation of air. 
 
 Artificial light in 
 our homes. It was 
 not so many years 
 ago that candles 
 were the sole source 
 of light in our homes, 
 and at the present 
 time, candle light 
 
 lends a pleasant glow to birthday and Christmas parties. 
 Up to the time of the Civil War, tallow candles, pine knots, 
 and heavy oils were common sources of light for reading. 
 People to-day use eighteen times as much light as they 
 did one hundred fifty years ago, and at one third the cost. 
 
 The first gas plant in America was started at Philadelphia 
 in 1815. Then candles cost two and one-half cents each 
 and would burn for seven hours. About the middle of the 
 nineteenth century the whaling industry was at its height, 
 and sperm oil was burned in lamps. Petroleum was first 
 used in 1858 for lighting purposes, and so rapidly did its 
 use grow that in 1860, two million barrels were produced, 
 and to-day, almost three hundred million barrels a year. 
 Although artificial gas was slow in its introduction, yet 
 it now plays a very important part in the lighting of our 
 
 Both these rooms receive the same amount of light. 
 One has dark wall paper and the other light. 
 
244 
 
 LIGHT IN THE HOME 
 
 houses. About 1890, electricity began to come into general 
 use for lighting purposes, and is now one of our best known 
 servants in the home. 
 
 Kerosene light. Kerosene oil lighting is still one of 
 the common methods of illumination, especially in country 
 
 homes. When oil first came 
 into use, it burned with a 
 smoky flame, until in 1783, 
 Argand, a Swiss physician, 
 made a ring-shaped wick with 
 a central draft. This allowed 
 convection currents to be set 
 up inside the wick, and thus 
 a larger flame could be fed 
 with oxygen. Flat wick lamps 
 which give smokeless flames 
 are now in common use, but 
 the central draft lamp gives 
 more light. The gasoline 
 lamp and acetylene lamp, 
 although used in many places, 
 are not in sufficiently com- 
 mon use to warrant a full 
 description here. 
 Gas in the home. Although not all of us are fortunate 
 enough to have either natural or artificial gas in the home, 
 yet we should know something about the gas burner and 
 its uses. When a candle burns, as we know, the paraffin 
 wax melts, becomes a vapor, and burns. You can prove 
 that the gas inside of the candle flame is not on fire by 
 passing a small tube into it, leading out the gas, and then 
 lighting it. When gas, passing from the outlet of an ordi- 
 
 AlR 
 
 Central-draft oil lamp. 
 
GAS IN THE HOME 
 
 245 
 
 nary burner, has not been previously mixed with air, 
 
 a yellow flame results. This is a very wasteful type of 
 
 burner. The Bunsen burner, in which 
 
 air is mixed with the gas, gives a clean 
 
 hot flame which is not very luminous. 
 
 A combination of this type of burner, 
 
 which produces much heat, with a 
 
 mantle which glows when heated, gives us 
 
 the Welsbach light. .Welsbach mantles 
 
 are made from compounds of two rare 
 
 metals, thorium and cerium, which when 
 
 heated to a high temperature give the 
 
 bright light we are so familiar with. 
 
 Am, 
 
 A Bunsen burner. 
 
 Experiment. To show the advantage of the mantle in gas lighting. 
 
 Connect a common fishtail burner and a Thorp gauge to the gas supply. 
 Light the burner and see how many cubic feet of gas per hour are 
 
 Effect of gas appliance on cost of gas. Black = minimum ; Black and white =- maximum ; 
 M = mean cost per hour. 
 
246 
 
 LIGHT IN THE HOME 
 
 
 registered. Replacing the fishtail burner by a mantle and burner, 
 how does the light produced in the two cases compare? How much 
 gas is being consumed in the latter case ? What is your conclusion ? 
 (If a Thorp gauge is not available, test the gas consumed in a specified 
 time by observing the small indicator of the gas meter dial.) 
 
 The first electric lamp. It is due Jto Thomas Edison 
 that we have the incandescent light. The story of its 
 invention is well known. He worked for a great many 
 years and spent hundreds of thousands of dollars in the 
 
 perfection of the bulb light, 
 patented in 1880, which he 
 furnished finally with a car- 
 bon filament, made of bam- 
 boo. The way in which 
 this filament gives light can 
 be explained better after we 
 have performed an experi- 
 ment to illustrate what 
 makes electricity give light. 
 Electricity is a form of 
 energy which is conducted 
 easily by metals. We have 
 all seen that the pipe con- 
 ducting liquids in the house offers resistance to them so that 
 they do not flow so easily. In somewhat the same way 
 wires offer resistance to electricity. That part of the elec- 
 trical energy used in overcoming this resistance to the wire 
 conductor is changed into heat, which when intense enough 
 produces light. This may be shown by the following ex- 
 periment : 
 
 Experiment. To show how electricity may be changed into light. (To be 
 performed by the teacher.) 
 
 The carbon filament incandescent lamp and 
 the modern tungsten lamp. 
 
THE FIRST ELECTRIC LAMP 
 
 247 
 
 Suspend a ten-foot length of fine iron wire (No. 26) from insulated 
 supports. Fasten one wire of a no- volt circuit to one end of the 
 iron wire, and bring the other end of this circuit in contact with the 
 other end of the wire. Move the end of the circuit wire along, shorten- 
 ing the length of the iron wire until it becomes red hot. All this heat 
 energy is produced at the expense of electrical energy. As the wire is 
 shortened the heat increases. The hotter the wire, the greater per cent 
 of electrical energy is changed to heat. 
 
 COST OF ELECTRIC LIGHT 
 
 4O Woctt rToryla -D Lamp 1907 - 1913 
 1000 Woctt ITajdUx- C Lamp 1914- -1920 
 
 Graph showing decrease in cost of electric lighting in forty years. A is the reduction 
 due to lamp improvement only ; B, due to lamp improvement and reduced rates 
 for current. 
 
 We thus see from the result of tbis experiment that it is 
 more economical to use electric bulbs which contain fila- 
 ments which can be raised to high temperatures. Why? 
 
 Experiment. To show the advantage of tungsten over carbon lamps. 
 
 Connect one or more small carbon lamps in a circuit with a kilowatt- 
 hour meter. Find the electrical energy used in running these lamps 
 for a definite time, say one hour. Replace the lamps by an equal 
 number of small tungsten lamps (25 watt), and find the electrical 
 energy consumed during an equal interval of time. 
 
 Each carbon lamp gives 16 candle power, and each tungsten lamp gives 
 20 candle power. Reckoned on the basis of candle power, what is 
 the ratio of cost of running the two types of lamps ? 
 
248 
 
 LIGHT IN THE HOME 
 
 The tungsten light. - - The old carbon filament is 
 rapidly being replaced by the tungsten lamp. The 
 
 carbon filament can 
 be heated to 1850 
 degrees Centigrade, 
 while the tungsten 
 filament can be 
 heated to 2100 de- 
 grees Centigrade, and 
 in bulbs which are 
 filled with nitrogen, 
 the temperature may 
 go still higher ; there- 
 fore we get a much 
 brighter light from 
 the tungsten lamp. 
 A one hundred candle 
 power tungsten, ni- 
 trogen-filled bulb re- 
 quires only about one 
 seventh as much elec- 
 tricity as the one 
 hundred candle 
 power carbon lamp. 
 The table on the fol- 
 
 GAS OPSN 
 
 GAS 
 
 CARBON ELECTRIC 
 
 Cost, 
 
 EUCTR1C 
 
 5 10 15 20 
 1000 CctTXoLle, 
 
 30 35 
 IT\ 
 
 This chart, suggested by the Bureau of Standards, 
 shows the relative cost of light from different illu- 
 minants, based on the following prices : candles, 
 i2fi a pound; kerosene, 15 i a. gallon; gas, $i per 
 1000 cu. ft.; electricity, io*i per kilowatt-hour. 
 Solid black represents cost of fuel, and shaded, lowinP" naP"P showi 
 cost of mantles and bulbs. Revise this chart in IUW1I1 5 P d 5 e 
 your notebook to agree with cost of these illumi- some common liffht 
 nants in your own city or town. null iigiit 
 
 intensities. A good 
 
 home project would be to find out the difference in the 
 cost of lighting your home with the fishtail gas flame, the 
 Welsbach gas flame, carbon filament electric lights, and 
 tungsten filament lights. 
 
METHODS OF LIGHTING 
 
 249 
 
 TABLE OF INTENSITIES OF COMMON TYPES OF LIGHTING 
 
 The common carbon incandescent lamp 
 
 The small tungsten incandescent lamp 
 
 The fishtail gas flame 
 
 The Welsbach gas flame 
 
 A zoo-watt tungsten incandescent 
 
 1 6 candle power 
 20 " " 
 
 22 " " 
 
 60 " " 
 
 Q2 " 
 
 // / ; i \ \ \ 
 ' / / ; I I ' \ ' 1 
 
 ' / I \ \ V ' 
 
 x /T*M 
 
 Explain how these pictures illustrate direct, indirect, and semi-indirect lighting. 
 
 Methods of lighting. Several ways of lighting by elec- 
 tricity are now in use. In direct lighting, the light is thrown 
 directly from the lamp or by a reflector to the place where 
 it is used. This produces a glare in some directions and 
 has some disadvantages which we shall study in connec- 
 tion with the eye. Direct lighting is economical because 
 little light is lost through diffusion or absorption. 
 
250 
 
 LIGHT IN THE HOME 
 
 In indirect lighting, an opaque reflector comes between 
 the eye and the bulb and all light is directed upward to a 
 white or light colored ceiling. Here the light is diffused, 
 and this resembles daylight in its general effect. It is not 
 economical, but is pleasant and restful for the eyes. In semi- 
 indirect lighting, a translucent reflector throws most of the 
 light to the ceiling. Some light passes through the shade. 
 There is no glare in this system, and its cost is interme- 
 diate between the other two systems. 
 
 Use of the score card. Here the boy and girl in the 
 country will probably have the advantage in natural light- 
 ing, but the city child will perhaps have better conven- 
 iences in artificial light. Study carefully to find out the 
 relative cost of your lighting system and make inquiries 
 as to the cost of light in your town, if you have gas or 
 electricity. What improvement in your home lighting can 
 you suggest? 
 
 SCORE CARD. LIGHTING MY HOME 
 
 
 
 
 
 MY SCORE 
 
 
 
 
 
 
 Total 
 
 SUNLIGHT 
 
 Three fourths of all 
 
 Half rooms have 
 
 No rooms have di- 
 
 
 
 
 rooms have di- 
 
 direct sunlight 
 
 rect sunlight (o) 
 
 
 
 
 rect sunlight (4) 
 All rooms well 
 
 (2) 
 Half rooms well 
 
 No rooms in which 
 
 
 
 
 
 lighted by natural 
 
 lighted by natu- 
 
 artificial light is 
 
 
 
 
 light. No arti- 
 
 ral light; no arti- 
 
 not needed before 
 
 
 
 
 ficial light needed 
 
 ficial light needed 
 
 sundown (o) 
 
 
 
 
 until after sun- 
 
 until after sun- 
 
 
 
 
 
 down (2) 
 
 down (i) 
 
 
 
 
 
 Home not directly 
 
 House partly shaded 
 
 House d ensely 
 
 
 
 
 shaded by trees 
 
 (i) 
 
 shaded (o) 
 
 
 
 
 or other build- 
 
 
 
 
 
 
 ings (2) 
 
 
 
 
 
 
 Well-lighted airy 
 
 Cellar not light but 
 
 Cellar dark and 
 
 
 
 
 cellar (2) 
 
 airy (i) 
 
 musty (o) 
 
 
 
 WINDOWS 
 
 Window space at 
 
 Window, space at 
 
 Window space less 
 
 
 
 AND 
 WALL 
 
 least floor space 
 (av. all rooms) 
 
 least 1 floor space 
 (2) 
 
 than floor space 
 (o) 
 
 
 
 PAPER 
 
 (4) 
 
 
 
 
 
USE OF THE SCORE CARD 
 
 251 
 
 SCORE CARD. LIGHTING MY HOME Continued 
 
 
 
 
 
 MY SCORE 
 
 
 
 
 
 
 Total 
 
 WINDOWS 
 AND WALL 
 
 Awnings or shutters 
 provided (2) 
 
 Shutters, no awn- 
 ings (i) 
 
 No shutters or awn- 
 ings (o) 
 
 
 
 PAPER 
 
 No dark hangings 
 at windows (2) 
 
 Dark hangings at 
 some windows (i) 
 
 Dark hangings at 
 most windows (o) 
 
 
 
 
 No rooms having 
 
 One half rooms 
 
 Three fourths 
 
 
 
 
 dark wall papers 
 
 having dark pa- 
 
 rooms having 
 
 
 
 
 (2) 
 
 pers (i) 
 
 dark wall paper 
 
 
 
 
 
 
 (o) 
 
 
 
 
 
 
 
 
 
 COST 
 
 Economical 
 
 Moderately eco- 
 
 Expensive (o) 
 
 
 
 OF 
 
 (Consult tables, 
 
 nomical (5) 
 
 
 
 
 ARTIFICIAL 
 
 page 245, and 
 
 
 
 
 
 LIGHTING 
 
 diagram, page 
 
 
 
 
 
 
 248) (10) 
 
 
 
 
 
 
 
 
 
 
 
 PROPER 
 
 Light used gives no 
 
 Sometimes direct 
 
 Usually direct light 
 
 
 
 LIGHTING 
 
 glare and does 
 
 light in eyes (i) 
 
 in eyes (o) 
 
 
 
 FOR ALL 
 
 not shine in eyes 
 
 
 
 
 
 KINDS OF 
 
 when reading or 
 
 
 
 
 
 WORK 
 
 at dining table 
 
 
 
 
 
 
 (2) 
 
 
 
 
 
 
 Strong light for 
 
 Fair light for sewing 
 
 Poor light for sew- 
 
 
 
 
 sewing (2) 
 Kitchen well lighted 
 
 d) 
 Good light at sink 
 
 ing (o) 
 Poor light all parts 
 
 
 
 
 (2) 
 
 or range, not at 
 
 of kitchen (o) 
 
 
 
 
 
 both (i) 
 
 
 
 
 
 Lights both sides of 
 mirror in bath- 
 
 Light on one side 
 bath mirror (i) 
 
 No light near bath- 
 room mirror (o) 
 
 
 
 
 room (2) 
 
 
 
 
 
 
 No carrying of 
 
 Necessary to carry 
 
 Always necessary to 
 
 
 
 
 lights from one 
 
 light to some 
 
 carry light from 
 
 
 
 
 part of the house 
 
 parts of the house 
 
 one room to an- 
 
 
 
 
 to another (2) 
 
 d) 
 
 other or to light 
 
 
 
 
 
 
 with matches (o) 
 
 
 
 
 
 
 
 
 
 CON- 
 
 Gas or electric 
 
 Gas or electric con- 
 
 Oil lamps used (o) 
 
 
 
 VENIENCE 
 
 wall switches (2) 
 
 trol at jet or 
 
 
 
 
 OF 
 
 
 socket (i) 
 
 
 
 
 LIGHTING 
 
 Switch on one floor 
 
 Switch control of 
 
 No switch control 
 
 
 
 SYSTEM 
 
 turns on light on 
 
 light upstairs and 
 
 from different 
 
 
 
 
 other floors (2) 
 
 down but not to 
 
 floors (o) 
 
 
 
 
 
 cellar (i) 
 
 
 
 
 
 Either floor sockets 
 
 Some, but insuffi- 
 
 No extra connec- 
 
 
 
 
 for electric con- 
 
 cient extra con- 
 
 tions (o) 
 
 .... 
 
 
 
 nection or extra 
 
 nections (i) 
 
 
 
 
 
 gas connection 
 
 
 
 
 
 
 for small heater 
 
 
 
 
 
 
 or gas iron (2) 
 
 
 
 
 
 
 Different amounts 
 
 Variation of light 
 
 Variation of light 
 
 
 
 
 of light easily ob- 
 
 intensity possible 
 
 difficult in any 
 
 
 
 
 tained in most 
 
 in only a few 
 
 room (o) 
 
 
 
 
 rooms (2) 
 
 rooms (i) 
 
 
 
 
 
 Lighting service 
 never interrupted 
 
 Service occasionally 
 interrupted (i) 
 
 Service frequently 
 interrupted (o) 
 
 
 
 
 (2) 
 
 
 
 
 
 GRAND TOTAL PERFECT SCORE SO 
 
 
252 LIGHT IN THE HOME 
 
 REFERENCE BOOKS 
 
 Adams, Harper's Electricity Book. Harper and Brothers. 
 
 Bachman, Great Inventors and their Inventions (Edison). American Book Com- 
 pany. 
 
 Barber, First Course in General Science, Chapter I. Henry Holt and Company, 
 
 Brownell, General Science, Chapter X. Blakiston's Son and Company. 
 
 Burns, Great Inventions (Electricity). Harper and Brothers. 
 
 Clark, An Introduction to Science, Chapters XXVI, XXX. American Book Com- 
 pany. 
 
 Gowin and Wheatley, Occupations, Chapter IX. Ginn and Company. 
 
 Hodgdon, Elementary General Science, Chapters X, XI. Hinds, Hayden, and 
 Eldredge. 
 
 Inventor, and Lamp (Lecture 8). General Electric Lecture Service, Schenectady, 
 N. Y. 
 
 Official Handbook, Boy Scouts of America. Doubleday, Page and Company. 
 
 Lynde, Physics of the Household. The Macmillan Company. 
 
 Smith and Jewett, Introduction to the Study of Science, Chapter IV. The Mac- 
 millan Company. 
 
 Tappan, Modern Triumphs (Edison and Electric Light). Houghton Mifflin Com- 
 pany. 
 
 Tappan, Wonders of Science. Houghton Mifflin Company. 
 
 Van Buskirk and Smith, The Science of Everyday Life, Project XII. Houghton 
 Mifflin Company. 
 
CHAPTER XVI 
 IMPORTANCE OF OUR EYES 
 
 Problems. i. To see how the eye resembles a camera 
 in structure. 
 
 2. To find out what colors are. 
 
 3. To learn what the common defects of the eye are and how 
 to remedy them. 
 
 4. To find out the defects of my own eyes. 
 
 5. To learn rules for proper care of the eyes. 
 
 Experiments and demonstrations. i. To show how the pupil of the 
 eye changes size in looking from a dark room toward a strong source of 
 light. 
 
 2. To test my own eyes for defects. 
 
 Project I. To REMEDY ANY EYE DEFECTS YOU MAY HAVE. 
 
 1. Have a competent person test your eyes for astigmatism, near- 
 sight, farsight, and color blindness. You can tell if you have eye- 
 strain. 
 
 2. Remedy any serious defects. 
 
 3. Explain the science involved in the eye defect and in the appli- 
 cation of the remedy. 
 
 How we see. One of the saddest results of the World 
 War is seen in a hospital where men blinded by gas or 
 other causes grope their way around in somber darkness. 
 How we pity them ! The loss of sight would be one of the 
 most terrible things that could happen to us. Then why 
 
 253 
 
254 
 
 IMPORTANCE OF OUR EYES 
 
 should we abuse these delicate organs we call the eyes? 
 The daytime is not long enough for us, so we provide 
 ourselves with artificial light and keep our eyes at work 
 part of the night. We read fine print in dim light, and 
 injure our eyes in a hundred ways. Our eyes are of so 
 much importance to us that it seems wise to devote an 
 entire chapter to them and their care. 
 
 Lenses and what they do. We have all tried to set fire 
 to a pile of leaves or paper with a burning glass. An 
 ordinary reading glass found sometimes on the library 
 table is a common example of a simple lens. If we look 
 at it in cross section, we find that it bulges outward in the 
 middle in both directions. We call such a lens double con- 
 vex. If we hold such a lens so that the sun shines through 
 
 it, and move a piece of 
 paper toward or away 
 from it, one place will 
 be found where only a 
 tiny spot will be lighted, 
 but this will be ex- 
 tremely bright, and 
 enough heat may be 
 concentrated to set the 
 paper on fire. This 
 point at which the sun's 
 rays have been brought 
 together (see F in fig- 
 ure) is called the focus. 
 When light passes 
 through the air to the glass, it moves in parallel rays, but 
 the glass bends the rays so that they come together at 
 one point. This point is called the principal focus of the 
 
 Which lens has the shortest and which the 
 longest focal length ? 
 
THE CAMERA 
 
 255 
 
 Essential parts of a plate camera. 
 
 lens, and the distance from that point to the center of the 
 lens is called the focal length. You can easily measure the 
 focal length of a lens by this method. 
 
 The camera. The study of a camera will help us to 
 understand the parts of the eye. If we carefully note the 
 parts of the camera 
 shown in the illus- 
 tration, we find that 
 it is a light-tight box 
 painted black on the 
 inside to absorb all 
 light rays, and hav- 
 ing a lens, a dia- 
 phragm for changing 
 the size of the open- 
 ing, and a shutter in 
 front which controls the time of the exposure of the photo- 
 graphic plate or film which is placed at the opposite end 
 of the camera. In a photographer's camera, such as is 
 shown in the illustration, a ground glass is placed at the 
 end where the plate is held when an exposure is made. 
 
 Experiment. To show how a lens is used in focusing 
 
 Materials : Double convex lens. White screen. Large carbon bulb. 
 
 1. Focal length. 
 
 Hold a double convex lens in sunlight at right angles to the rays. 
 Place a screen of white paper back of the lens. Adjust the distance be- 
 tween them until the spot of light (the sun's image) is the smallest. 
 Measure the distance from the lens to the screen. This distance is 
 called the focal length of the lens. 
 
 Compare the focal length of a thick lens with that of a thin lens by 
 this method. 
 
 2. Focusing as done in the camera. 
 
 Hold a double convex lens about three times its focal length from 
 a large carbon lamp which is lighted in a dark room. Move a screen of. 
 
256 IMPORTANCE OF OUR EYES 
 
 white cardboard back and forth until a position is found where a sharp 
 image of the filament is seen on the screen. Move the light farther away. 
 What must you do with the lens to give a second sharp image on the 
 screen? Compare the two images. Move the lens towards the light 
 until an enlarged image results. Explain how this experiment illustrates 
 the use of a lens in the ordinary camera and also in the enlarging camera. 
 
 What is color ? If you have ever watched waves com- 
 ing in to the shore, you may have noticed that sometimes 
 the distance beween two successive waves is quite great, 
 and sometimes it is much less. We have learned that 
 light is caused by waves of ether which come to us from the 
 sun or from other lighted objects. Only a very small 
 portion of all the ether waves affect our eyes, and give us 
 the sensation we call light. Ether waves producing light 
 differ in length, the longest being one thirty-three thou- 
 sandth of an inch in length, and the shortest that we can 
 see, one sixty-six thousandth of an inch in length. The 
 longest of these visible waves causes the sensation of red, 
 and the shortest gives the sensation violet, while all other 
 colors come between these. Color, then, is a property 
 of light waves, and each particular color is due either to 
 waves of some particular length, or to mixtures of waves 
 which produce different colors. 
 
 How we see color. When all the different light waves 
 from the sun are mixed together, white light is pro- 
 duced, as we see when sunlight is reflected by white paper. 
 White substances are those which reflect all sunlight. 
 Black objects are those which absorb all of it. Any object 
 which absorbs all the light waves except the very long ones 
 is red, because it reflects to your eyes only the red waves. 
 In the same way, any object which absorbs all the waves 
 except the very short ones would look violet in color. 
 This seems very strange, but we can prove that light is 
 
STRUCTURE OF THE EYE 
 
 2 57 
 
 A prism separates white light into colors of the spec- 
 trum. 
 
 made up of these various colors by passing it through a 
 prism, a triangular shaped glass such as we often see in the 
 candelabra in old houses. If a ray of sunlight were 
 passed through this prism to a screen in a darkened room, 
 we could see all the 
 rainbow colors of the 
 spectrum. If we al- 
 lowed this light to 
 pass through a sec- 
 ond prism placed in 
 a reversed direction 
 (see diagram) , the 
 colors would again 
 be brought together, 
 and passed out as white light. The rainbow is nothing 
 more or less than light passing through falling drops of 
 water, which act as prisms, thus separating light into its 
 elements, red, orange, yellow, green, blue, and violet. 
 Structure of the eye. We are now ready to learn 
 
 something about the 
 structure of the eye. 
 Our eyes are among 
 the most delicate and 
 wonderful structures 
 in the body. We 
 abuse them con- 
 stantly, yet they serve 
 us well. Notice how 
 
 The spectrum colors can be reunited by a second 
 prism so as to produce a beam of white light. 
 
 well they are protected by being set in a bony socket, and 
 how admirably the lashes serve to keep out dust and dirt. 
 See, too, how tears flow every time any dust gets upon 
 the delicate membranes of the eye. Also observe, how the 
 
 H.-.WHIT CIV, SCI. IN THE HOME I? 
 
258 IMPORTANCE OF OUR EYES 
 
 eye can be turned in different directions, due to the little 
 paired muscles which serve to move the eyeball. 
 
 If we study a section as shown, by cutting the eyeball 
 in halves from front to back, we find that it is more like the 
 
 camera than it is on the 
 surface. In the front there 
 is a transparent lens which 
 makes a little picture at 
 the back of the eye, just as 
 the camera lens makes a 
 picture. This lens, how- 
 ever, is not fixed in shape 
 like that of a camera, Lut 
 
 Section of the eye. Find the parts which J c fl^viKlA anrl ic mxr\p> 
 correspond to those in a camera. 
 
 thicker or thinner by move- 
 ment of delicate muscles, thus doing away with the ne- 
 cessity of moving the lens forward or backward in order 
 to get a picture in focus. 
 
 The main portion of the eye is filled with a colorless 
 substance, the vitreous humor, while back of this lies a 
 pigmented receiving organ connected by nerves with the 
 brain, known as the retina. It is on this sensitive surface 
 that our images are received and sent to the brain by the 
 optic nerve, so that we really see in the brain, although the 
 picture is received on the retina. There are three coats 
 covering the eyeball, a tough outer coat, the sclerotic, a 
 middle coat, the choroid, while the inner coat is the retina. 
 These coats are open at the front, and the choroid, which 
 is filled with pigment, or color-bearing material, makes a 
 kind of curtain. It is this curtain, called the iris, which 
 gives the color to a person's eye. The iris controls the 
 amount of light which passes through the hole, or pupil, 
 
HOW THE EYE ADAPTS ITSELF 259 
 
 into the inside of the eye, just as the diaphragm in the 
 camera controls the light. On a bright day, would you 
 expect the pupil of the eye to be larger or smaller than on 
 a dull day? Why? 
 
 Experiment. To see the pupil of the eye change in size. 
 
 From a room in which all the other windows are darkened look out of the 
 window into a very bright sky for a moment. Examine the eye in a 
 mirror. Then turn quickly and look at your eyes in the mirror with 
 your back to the light. Result? Explain. 
 
 Control of focusing. The eye adjusts itself quickly 
 to see objects at different distances. This is done by 
 means of tiny muscles called the ciliary muscles, which 
 change the thickness of the lens. A flat lens focuses well 
 on distant objects, while a thick lens focuses on objects 
 near at hand. If you look at an object some distance 
 off, and then suddenly holding a book before your eyes try 
 to focus on the page, you will find that the print is blurred 
 for a moment before you are able to see. This change of 
 focus is called accommodation. 
 
 How the eye adapts itself to different intensities of 
 light. It has been found that different intensities of 
 light in the home are desirable for different kinds of work. 
 The following table gives the intensity in foot candles, 
 which means the amount of light a candle would give at a 
 distance of one foot from an object. 
 
 
 DESIRABLE AT TIMES 
 
 MINIMUM 
 
 Hall and stairways . . 
 Living room and dining 
 room . . , 
 
 i 2.5 foot candles 
 3 6 foot candles 
 
 0.5 foot candle 
 i 5 foot candles 
 
 Sewing room .... 
 
 6 12 foot candles 
 
 3. foot candles 
 
260 IMPORTANCE OF OUR EYES 
 
 The eye is able to adjust itself to different amounts of light, 
 within rather wide limits, without harm. In order to avoid 
 
 straining the eye, it 
 is necessary to have 
 enough light. Much 
 harm is sometimes 
 done when we are 
 young by trying to 
 
 How does the eye adjust itself to different intensities read hi insufficient 
 of light ? T . , . , 
 
 light ; just as much 
 
 harm has been done by looking into a blinding light, or 
 trying to look at the sun, as some youngsters do at times 
 to " stunt " each other. 
 
 Some defects of the eye. Although the eye is a wonder- 
 ful piece of mechanism, it has several common defects. 
 Fortunately, due to a study of the eye and of the science 
 called optics, we are now able to remedy most of these de- 
 fects very easily, especially by the use of glasses. It is 
 estimated that one person in every four has some defect 
 in vision. Nearly twenty-five per cent of the school chil- 
 dren in Massachusetts and over thirty per cent of the 
 school children in New York have eye trouble of some 
 kind. The most common defect of the eye is astigmatism. 
 This is usually due to a slight uneven curvature of the 
 cornea, or the lens. It can easily be discovered by use of 
 the diagram on page 26 1 . Look at either of the figures with 
 one eye closed. If some of the lines appear blurred or 
 thicker than others astigmatism is present and should be 
 corrected with glasses, as this defect is a frequent cause 
 of headache. 
 
 The next most common defect is nearsightedness. In 
 this case the eyeball is too long from front to back, or the 
 
SOME DEFECTS OF THE EYE 
 
 261 
 
 Diagrams to be used in testing for astigmatism. 
 
 lens is too thick, so that the image of distant objects is 
 focused in front of the retina. This tends to make one 
 squint the eye, and also to hold the object near to the 
 eye. Nearsightedness is quite common in children, and is 
 easily corrected by the use of glasses which place the focus 
 in the right place. 
 
 Nearsightedness is remedied by means of concave eyeglass lenses. 
 
 Farsightedness is another common defect. In farsighted- 
 ness, the eyeball is too short, or the lens too thin, and the 
 image if it could be found would fall behind the retina. 
 Hence we get a blur on the retina. This is a more diffi- 
 cult defect to recognize, because people often do not know 
 its presence until they are made aware of it by constant 
 headaches. As a person grows older, he has a tendency 
 to become farsighted. It is frequently the case that elderly 
 persons when reading need one kind of lens, and for or- 
 dinary purposes, a second lens. For this purpose a double 
 
262 IMPORTANCE OF OUR EYES 
 
 glass, called bifocal, combining the two lenses in one is 
 often used. 
 
 Farsightedness is remedied by means of convex eyeglass lenses. 
 
 Testing of eye defects. A very simple exercise for 
 testing most eye defects is given in the following labora- 
 tory experiment. 1 
 
 Experiment. To test my own eyes for defects. 
 
 Y F E V 
 
 A. Test for Farsightedness 
 
 Method: Using the Snellen test cards, locate the finest line that can 
 be read at a distance of 20 feet. Test each eye separately, covering the 
 
 eye not in use with 
 a piece of cardboard. 
 Then place a pair of 
 
 How far away can you read these letters? Measure s P ectacles Wlth a 5 
 the distance. Twenty feet is a test for the normal plus diopter lens be- 
 fore the eyes. If as 
 
 fine or a finer line can now be read, then farsightedness is present and an 
 oculist should be consulted, especially if headaches or other symptoms 
 of eye defects are present. Farsightedness is one of the most frequent 
 causes of eyestrain and is hard to detect because the eyesight seems 
 .so good. 
 
 B. Test for Nearsightedness 
 
 Method: Use the above-mentioned charts. Determine the finest type 
 you can read at a distance of 20 feet. If it is larger than the 20/20 
 line, then your vision is defective and you should probably consult 
 an oculist, especially if you have any symptoms of eyestrain. 
 
 1 This test was prepared by Dr. Lucius J. Mason of the Department of 
 Biology, DeWitt Clinton High School, New York. 
 
EYESTRAIN 263 
 
 C. Test for Astigmatism 
 
 Method: Use the clock dial disk at 20 feet. If some lines are blacker 
 than others, then astigmatism is present. If headaches or other symp- 
 toms are present, then you should consult an oculist and have glasses 
 fitted to correct this trouble. 
 
 Eyestrain. Eyestrain frequently results from attempts 
 to overcome defects of the eye, and also by putting the 
 eyes to too severe use, thus taxing the blood vessels of the 
 eye, and the nerves, which in turn affect the nerves of 
 the head and stomach. The following are some of the 
 things which we often call upon the eye to do : 
 
 1. Change focus for different words in the line. This is 
 because they vary in their distance from the eye, and only 
 in two places are the eyes equally distant from the words 
 being read. 
 
 2. Insufficient light. The illumination of the object is 
 of extreme importance as the light fades at close of day. 
 For then the white paper of a printed page becomes darker 
 and darker, until finally it reflects very little more light to 
 the eye than the printed letters ; consequently the letters 
 no longer stand out, and we have great eyestrain. 
 
 3. The wrong position produces glare. One of the 
 most frequent errors around the home table is that boys 
 and girls frequently face the light rather than allow it to 
 come over the shoulder, or from above. Overhead light- 
 ing systems are far better than any light which throws a 
 glare on the paper. Reading in an unsteady or flickering 
 light, particularly on moving trains, is extremely bad for 
 the eye. 
 
 4. Too much light in the field of vision is as bad as too 
 little light. For most purposes the student lamp, in- 
 candescent electric light, and Welsbach gas light of mod- 
 
264 IMPORTANCE OF OUR EYES 
 
 erate intensity are preferred to the stronger lights. Fine 
 print and the use of glossy or colored papers are also matters 
 that we should avoid. The use of large type for young 
 children is particularly important, because the eye then is 
 more elastic, and extra strain placed on the muscles of the 
 eye may lead to permanent harm to the curved surfaces. 
 
 Color blindness. In order to qualify as an engineer 
 on the trains, or as pilot, where it is necessary to distin- 
 guish colors, one must first submit to a test for color blind- 
 ness. 1 From three to four per cent of boys and about 
 one per cent of girls are color blind. This is one reason 
 why some boys cannot match colors as well as girls can. 
 The most common form of color blindness is the inability to 
 distinguish between red and green. 
 
 Suggestions for the care of the eye. i. Do not sit so 
 that direct light reflected from book, paper, or highly 
 polished floors will cause a glare. 
 
 2. Do not sit facing strong artificial or natural light. 
 
 3. Do not sit so that your shadow falls upon your work. 
 
 4. Do not use a flickering light. 
 
 5. Do not read on a train or other moving conveyance. 
 
 6. Adjust the intensity of the light to your needs. 
 Strong light is needed to read fine print. 
 
 7. Do not use the eyes when they ache or when you 
 yourself are fatigued. 
 
 Correction of defects. If you have discovered from 
 the laboratory exercises that you have eye defects, go at 
 once to an oculist and have glasses to correct them. 
 
 If the eyes are red or inflamed or if water runs from 
 them, or if the lids are sore, see a physician at once. Avoid 
 
 1 Holmgren's woolens and Westcott's color slide are useful in detecting 
 color blindness. 
 
REMOVAL OF CINDERS 265 
 
 doing fine work and reading in bad light. If the eyes 
 pain, use a cloth heated with very hot water. A two per 
 cent boracic acid solution is an excellent wash, and may 
 be used frequently. This, or a salt solution made of one 
 teaspoonful of salt to a pint of boiling water, may be used 
 to wash the eye after getting a cinder in it. 
 
 Removal of cinders. Sometimes particles of dust 
 or cinders get into the eye. These are usually washed 
 out by tears which flow as a result of the irritation. Some- 
 times, however, they have to be removed. In the case 
 of the lower lid, there is little trouble ; if one pulls the lid 
 down the speck can easily be removed with the use of a 
 clean handkerchief. The upper lid is more difficult to 
 pull back. In order to do this successfully, have the 
 person look downward, place a 
 small pencil against the upper 
 portion of the lid, take hold of 
 the eyelashes, turn the lid up- 
 ward and back over the pencil, 
 
 and the lid is in such a position Turnin * the ^ back to remove 
 that the speck can easily be lo- 
 cated. Sometimes a tiny sharp-pointed bit of glass or cinder 
 becomes embedded in the surface of the cornea. A drop of 
 olive oil in the eye prevent* irritation until with the help of 
 an expert physician it can be removed. 
 
 REFERENCE BOOKS 
 
 Allen, Civics and Health (For teachers), Chapter VII. Ginn and Company. 
 
 Brownell, General Science, Chapter I. Blakiston's Son and Company. 
 
 Clark, Introduction to Science, Chapters XXVI, XXVIII, XXIX. American Book 
 
 Company. 
 
 Hodgdon, Elementary General Science, Chapter X. Hinds, Hayden, and Eldredge. 
 Hunter, A Civic Biology, Chapter XXIII. American Book Company. 
 
266 
 
 IMPORTANCE OF OUR EYES 
 
 Hunter, Laboratory Problems in Civic Biology, Chapter XXIV. American Book 
 
 Company. 
 
 Ritchie, Physiology and Sanitation (Chapter on Eye). World Book Company. 
 Routledge, Discoveries and Inventions of the Nineteenth Century, pages 374-402 ; 
 
 529-551. Routledge. 
 
 Stiles, Human Physiology, Chapter XI. W. S. Saunders Company. 
 Thompson, Boys' Book of Sports, pages 291-301. Century Company. 
 
 SCORE CARD. CARE OF MY EYES 
 
 SCORE 
 
 Perfect 
 Score 
 
 My 
 
 Score 
 
 Use different intensities of light for different kinds of work. 
 
 (See table, page 259) 2.5 
 
 Never look into " blinding " light 2.5 
 
 Do not use flickering light, for work 2.5 
 
 Do not use dim light for reading 2.5 
 
 Do not read on cars 2.5 
 
 Correct position of light when reading. (No glare on 
 
 paper; light from above) . . 2.5 
 
 Correct position of light when writing. (Light over left 
 
 shoulder for right-handed people) 2.5 
 
 Do not read fine print for long period of time .... 2.5 
 Do not use too strong a light for reading. Lights that 
 
 make glare are bad 2.5 
 
 Never face strong light when reading or doing other fine 
 
 work 2.5 
 
 Strong light used for sewing or other fine.work .... 2.5 
 
 Do not use eyes when they ache 2.5 
 
 Do not use eyes when tired 2.5 
 
 Bathe eyes in hot salt water if they ache 2.5 
 
 Wash frequently in boracic acid if inflamed 2.5 
 
 Can remove dirt by rolling lid 2.5 
 
 Eyes examined by oculist once a year 2.5 
 
 Glasses adjusted by oculist, when needed . . .... 2.5 
 
 Glasses used constantly in case of eye defects . . . . 2.5 
 
 Eyes tested and found glasses not needed 2.5 
 
 TOTAL 50.0 
 
PART V. THE HOME AND ITS 
 SURROUNDINGS 
 
 CHAPTER XVII 
 MAKING AND BEAUTIFYING THE HOME 
 
 Problems. i. To find out the chief materials of which 
 our houses are made. 
 
 2. To see what arrangement of rooms in the house is de- 
 sirable. 
 
 3. To learn what the essential qualities of the important 
 rooms in the house are. 
 
 4. To see what decorations can be used to make the house 
 beautiful. 
 
 Experiments. i. To discover the relation of markings in trim to the 
 cutting of wood. 
 
 2. To make concrete of various mixtures and compare properties. 
 
 Project I. To PLAN THE IDEAL HOUSE. 
 
 1. Make floor plans of your own house. 
 
 2. Study plans made by others. Cut plans and photos from maga- 
 zines. What are their good and their bad features ? 
 
 3. Study your friends' houses. 
 
 4. Finally make floor plans for what you consider an ideal house 
 for your own family. 
 
 5. Discuss materials you would select for building and give rea- 
 sons, and tell how you would decorate the house within. 
 
 267 
 
268 MAKING AND BEAUTIFYING THE HOME 
 
 6. Discuss the wall papers and decorations used in the different 
 rooms. 
 
 7. Get furniture catalogues and make selection of ideal furnish- 
 ings for each room in the house. 
 
 8. Report on your project in class. 
 
 Homes of to-day. We know that homes of the present 
 day are very different from what they were when primi- 
 tive man lived on the earth. The complexities of mod- 
 ern life have made so many demands that now the home is 
 
 a very different place 
 from what it was even 
 a generation ago. No 
 two homes are alike. 
 Each one should be 
 suited to the locality 
 and to the people who 
 live in it whether it be 
 on the farm, in a town, 
 or in the big city. One 
 of us may live in a 
 frame house, another in 
 a brick row, and a third 
 
 Annual rings shown in cross section of wood. 
 
 in an apartment or 
 
 tenement, but wherever we live, our home is the place where 
 we sleep at night, where we eat, and best of all, where 
 family life centers. The purpose of this chapter is first, 
 to learn something about the materials out of which our 
 houses are constructed, and then something about the 
 decoration of the home and its grounds. 
 
 Building materials. If you make a list of all the 
 materials that are used in building a house you find that 
 wood, stone, glass, concrete, and metals have an important 
 
BUILDING MATERIALS 
 
 269 
 
 part. Wood is still one of the most used building ma- 
 terials in this country. Frame houses are much more 
 numerous than those of brick, stone, and concrete. The 
 quality of the wood depends on the kind of tree which 
 produces it, and the beautiful grain that is visible in some 
 woods is nothing more or less than the so-called annual 
 rings which appear as a result of growth in certain kinds of 
 trees. The material in the board or beam or in the mold- 
 ing or mantle of a room is composed of millions of dead 
 cells, the walls of which only remain. These walls are 
 hollow, living matter has gone from them, and when 
 wood is, finished, these holes are filled up with paint, oil, 
 wax, varnish, and whatever substance is used to give wood 
 its finished appearance. Although wood is necessary for 
 some parts of the house, it is not the safest material for 
 construction because of its liability to burn. Wooden 
 shingles should be treated with a solution to make them 
 wear longer, and to protect 
 us from fire. 
 
 Experiment. To show the rela- 
 tion of the markings in trim 
 to the cutting of wood. 
 
 Materials : Diagrams, school 
 
 furniture. Hough's sections 
 
 of woods. 
 Method : Examine the sections 
 
 shown you. Compare with 
 
 figure showing cross section 
 
 radial and tangential cutting 
 
 of timber. 
 
 Note : Most lumber is cut tangentially . Hence the yearly rings take 
 
 a more or less irregular course. The grain of wood is caused by the fibers 
 
 not taking straight lines in their course in the tree trunk. In many cases 
 
 the fibers of the wood take a spiral course up the trunk, or they may wave 
 
 outward to form little projections. Boards cut from trees with irregular 
 
 Diagrams of sections of timber, a, Cross 
 section, b, Radial, c, Tangentials. 
 
270 MAKING AND BEAUTIFYING THE HOME 
 
 fibers will show the effect seen in many of the school desks, where the 
 annual rings appear to form small elliptical markings. 
 
 Study the top of your desk, the wainscoting, the floor, and any other 
 wood at hand to determine the plane at which it was cut. Study the 
 figures and compare with the specimens of wood just noted. Can you 
 observe any difference in the color of the wood ? 
 
 Conclusion: What is the common method of cutting wood for trim? 
 Why? Does most dried wood show any difference between heart and 
 sap wood? What is this difference? 
 
 A granite quarry. 
 
 Stone as building material. Although not many single 
 houses are built of stone, yet in some parts of the coun- 
 try, where it can be obtained easily, stone makes an ex- 
 cellent building material. Many an old house in New Eng- 
 land was built in part, at least, from the bowlders and 
 loose stones which were found scattered around in the 
 vicinity. About eighty millions of dollars' worth of stone 
 is used in this country every year. Most of it is lime- 
 stone, sandstone, or granite. Limestone is found in many 
 parts of the United States, and while much of it is used, 
 as the Indiana limestone, for buildings, far more is used now 
 
ARTIFICIAL STONE 271 
 
 in the manufacture of lime for cement and fertilizer. Sand- 
 stone is easily quarried, and some kinds are very durable. 
 The brownstone houses in many cities show early signs 
 of decay ; this is because of a poor grade of stone having 
 been used. The " life " of a building stone is the length 
 of time before it shows signs of crumbling or chipping. 
 Compare the life of building stones as given in the fol- 
 lowing table. Granite, although extremely hard and du- 
 rable, is not very desirable for small houses. Slate is used 
 for roofing many houses. While it makes a hot roof, it 
 also makes a safe and durable one. 
 
 STONE 
 
 LIFE IN YEARS 
 
 Micaceous limestone 
 Micaceous brownstone (sandstone) 
 Compact brownstone (sandstone) . 
 Marble 
 
 2 to 15 
 15 to 30 
 15 to 30 
 40 to 80 
 
 Fine marble 
 
 50 to 100 
 
 Granite 
 
 57 to 200 
 
 Artificial stone. We are coming more and more to use 
 cement, hollow tile, and concrete in the construction of 
 our houses. Some of the most beautiful, as well as econom- 
 ical, small houses are now made of concrete or hollow tile, 
 with a coating of stucco, a kind of plaster which is placed 
 over the outside of the house. It has the advantage when 
 used, over wooden houses, of giving protection against fire. 
 Lime and sand are important building materials also. 
 Ordinary mortar made by mixing lime with sand and 
 water hardens more slowly than cement, the hardening 
 being caused by the taking up of carbon dioxide, which 
 changes the lime to calcium carbonate, or as the mason 
 
272 MAKING AND BEAUTIFYING THE HOME 
 
 says, " causes it to set." Many of our tall buildings, 
 as the " skyscraper " shown in the illustration, are made 
 
 of concrete, built upon 
 rods of steel and wire 
 mesh. Concrete, as we 
 know, has recently come 
 into use even for build- 
 ing ships, and many 
 other different uses are 
 made of it. 
 
 Experiment. To make con- 
 crete of various mix- 
 tures and to compare 
 properties. 
 
 Materials: Portland cement. 
 Sand. Steel knitting nee- 
 dles. Frame with six com- 
 partments, each about i 
 inches deep, i inch wide, 
 and 10 inches long. Mix 
 sand and cement dry, 
 in proportions indicated. 
 
 Then add water to make a pasty mass which slides easily from the 
 trowel. Make the following mixtures and pour them into the 
 frames : 
 
 A skyscraper, built mostly of concrete. 
 
 TEST 
 
 CEMENT 
 
 SAND 
 
 i 
 
 All cement 
 
 o 
 
 2 '-_*.- 
 2 
 
 i part cement 
 i part cement 
 
 2 parts 
 4 parts 
 
 A 
 
 i part cement 
 
 6 parts 
 
 5- 1 ....'. ., ,, g 
 
 6 2 
 
 i part cement 
 i part cement 
 
 5 parts 
 6 parts 
 
 
 
 
 1 Reinforce by putting in five steel knitting needles well spaced. 
 
 2 Instead of using sand use dark earth or loam. 
 
GLASS IN THE HOME 
 
 273 
 
 Let the mixtures harden from three to four weeks. Examine for ap- 
 pearance. Test for strength. If supported at the ends, how much weight 
 across can be supported? Conclusions? 
 
 Brick houses. Many of us who dwell in cities, and some 
 of us who live where clay is abundant, may live in brick 
 houses. Bricks, as 
 most of us know, 
 are made from wet 
 clay which is ground, 
 placed in molds and 
 then baked. All 
 bricks must be 
 baked, and by vari- 
 ous processes, a glaze 
 is put on the outside 
 of some, which ren- 
 ders them more or 
 less waterproof . Or- 
 dinary bricks, as one 
 can prove by an ex- 
 periment, take up a 
 great deal of water, 
 and therefore are Brickmaking. 
 
 apt to crack and crumble in very cold regions. 
 
 Glass in the home. We do not always think of glass 
 as a building material, yet it is a very important one, as 
 there is no satisfactory substitute for it. In these days of 
 sun parlors, large windows, and inclosed porches, glass is 
 more and more extensively used. Window glass is manu- 
 factured out of sand mixed with lime and compounds of 
 soda, melted at a high temperature, and then blown by 
 machinery into great cylinders which are later . cut and 
 
 H.-WHIT. CIV. SCI. IN THE HOME l8 
 
274 MAKING AND BEAUTIFYING THE HOME 
 
 placed in furnaces, flattened out, smoothed off, and finally 
 cut into sizes used by the trade. 
 
 Choosing a home. Although boys and girls do not 
 often have an opportunity to choose their own homes, 
 yet it is always well to have reasons for selecting one's 
 neighborhood. There are many advantages in the city 
 which are often lacking in the country, such as paved 
 
 A well-kept country home. 
 
 streets, sidewalks, good schools, churches, and theaters, 
 and above all ample protection against disease in the form 
 of good water supplies, sewage systems, and a Board of 
 Health. Yet on the whole, most boys and girls prefer to 
 live in the country. For here we find fresh air and sun- 
 shine and room for games. Here we may keep pets. 
 Here we may have a garden and orchard, and here are 
 walking and riding, swimming, boating, hiking, and picnick- 
 ing, pleasures which all country boys and girls know. A 
 detached house has its advantages, as well as its disadvan- 
 
THE FLOORS OF A HOUSE 
 
 275 
 
 tages. It is preferable to a large apartment or tenement 
 house five, six or twenty -five stories high, with dark halls 
 and tiny rooms. 
 
 A well-planned house. We may not be able to own 
 the house in which we live, still, since we are aiming at 
 ideal conditions, we ought to know something about house 
 planning. A study of the accompanying diagram will 
 
 UVING!?OOM HAU, 
 
 In what respects is this a good first floor plan ? Has it any defects 1 (After 
 Van Rensselaer.) 
 
 show us a well-planned small house. What rooms are 
 necessary? What rooms could be dispensed with? In 
 a well-planned house, we have a hall, living room, dining 
 room, kitchen, and closets on the first floor, bedrooms 
 and bath on the second floor, and a well-ventilated base- 
 ment which is provided with a heating apparatus, vege- 
 table closet, storage room, and laundry. 
 
 The floors of a house. Floors to be durable should 
 be made of hard wood, and should have an inconspicuous 
 
276 MAKING AND BEAUTIFYING THE HOME 
 
 iiii 
 
 
 
 raLle. 
 thin 
 
 grain. Where soft wood is used, the cracks may be filled 
 with crack filler, which can be made at home of a combina- 
 tion of flour paste and the pulp of damp newspaper, and 
 the floors then given two or three coats of hard paint to 
 
 make them more du- 
 Rugs are better 
 carpets, because 
 they can be more easily 
 cleaned and thus some 
 of the dangers from dust 
 are avoided. 
 
 Color in the home. - 
 How many times have 
 you gone into a home 
 
 Types of artistic rugs. Only part of rugs shown. where ^ strange CQm _ 
 
 bination of color of the wood, wall paper, and hangings of- 
 fended the eyes, and how often have you gone into a home 
 in which the paper and woodwork blend, thus giving a feel- 
 ing of comfort and homelike warmth ! One reason why one 
 room is light and another dark is the amount of sunlight 
 absorbed by the walls. A glance at the following table will 
 give some idea of how this differs : 
 
 Amount of Sunlight Absorbed by Various Materials 
 
 Clean glass . . -'. . . 5 % 
 
 White paper 18% 
 
 Newspaper 4% 
 
 Pink wall paper 50% 
 
 Yellow wall paper .... 60% 
 
 Dark brown wall paper . . 87 % 
 
 Dark green wall paper . . . 95 % 
 
 Deep blue wall paper . . . 96 % 
 
 Navy blue cloth .... 98 % 
 
 Black velvet . .'. . . . 99% 
 
 To make a room bright and cheerful in the evening, 
 remember that colors do not have the same value in 
 artificial as in natural light, for example, blue objects lose 
 
THE IDEAL BEDROOM 
 
 277 
 
 some of their richness in an artificial light. Blue is a cold 
 color and may be used in a bright, sunny room. Red and 
 yellow are warm and help to lighten rooms which are 
 naturally dark. Light colors increase the apparent size 
 of a room and give it the effect of cleanliness and good 
 cheer. While dark colors make a room seem smaller, 
 and while they, produce an effect of dignity and richness, 
 very often they make a room look gloomy, and make it 
 difficult to light. Wall 
 papers in general are 
 more restful and better 
 for the eyes if used in 
 plain colors, such as 
 tans, buffs, blues, and 
 reds. Papers with a 
 gaudy pattern in which 
 there is much contrast 
 are not restful to the 
 eye, nor do they make a 
 good background for pictures. Rough papers collect the 
 dust and are hard to clean. In a rented house, one should 
 insist that the papers in the bedrooms be changed, and if 
 possible, have the kitchen walls thoroughly painted before 
 taking possession. Can you see why ? 
 
 The ideal bedroom. Did you ever think that you 
 spend about a third of your life in your bedroom ? Since 
 this is so, a bedroom is a very important place and we 
 should treat it as such. Pure and sufficient air is most 
 important. Our bedroom should have at least one large 
 window, and if possible, two. At night, even in the 
 winter time, these windows should be open, both top and 
 bottom, so that a current of cool, pure, and fresh air may 
 
 Which wall paper makes the most pleasing back- 
 ground ? 
 
2 7 8 
 
 MAKING AND BEAUTIFYING THE HOME 
 
 come to us while we sleep. As a rule air is purer at night 
 than in the daytime, especially in the city, because at 
 that time there is less dust and smoke in it. We should 
 avoid drafts in our ideal bedroom ; this can be done by 
 placing a screen in front of the window. The furnish- 
 ings, even for the girl who likes pretty things, should be 
 
 
 Name the good points of this bedroom. 
 
 plain and simple. There should be few hangings as they 
 collect dust and dirt. It is better to have the walls painted 
 thani papered, especially in a rented house. Do you see 
 why? The floor should be uncarpeted, painted or waxed, 
 and have movable rugs, so that it may easily be kept 
 clean and sweet. A painted iron bedstead, with movable 
 springs and a moderately hard mattress, makes the best 
 bed for young growing boys and girls. If you study in 
 
THE LIVING ROOM 
 
 279 
 
 your room, a shaded electric bulb, gas mantle or oil lamp 
 gives a satisfactory light. 
 
 The living room. What is jollier than a family party 
 grouped around a fireplace in the living room? A 
 living room without a fireplace can be made attractive 
 and homelike with a big table, plenty of books, a well- 
 placed central light around which the family can gather in 
 
 Why is this an ideal living room ? 
 
 the evening, and a few good pictures and hangings on the 
 wall. The wall paper should be plain rather than fig- 
 ured, and not so highly colored that it is not restful to the 
 eye. A large rug rather than a carpet should partly cover 
 the floor. There should be a comfortable chair for each 
 member of the family, bookcases filled with favorite books, 
 and a comfortable couch. 
 
 The ideal dining room. Here, as in the living room, 
 the furniture should be comfortable and homelike. The 
 
280 MAKING AND BEAUTIFYING THE HOME 
 
 table should be large enough for all to have plenty of space, 
 and the dishes and glassware should be abundant. Re- 
 member that cleanliness of dishes, utensils, and food, 
 will go a long way in keeping us well, especially during 
 
 An ideal dining room. 
 
 hot weather. Flies must be kept away from the food and 
 dishes, for flies are disease carriers. There should be a 
 closed china closet in the room, so that dishes will be 
 kept free from dust and flies. The draperies should be few, 
 and the floor bare or covered with an easily -moved rug. 
 
 The ideal kitchen. The kitchen, although it may 
 not seem so important to the average boy or girl, is really 
 one of the most important rooms in the house. Here 
 food is prepared, dishes are washed, food supplies stored, 
 and frequently the family washing done. This requires 
 a good gas or coal range, a fireless cooker, especially for 
 use in hot weather, exposed plumbing, a large sink and 
 stationary tubs. It goes without saying that mother 
 must have plenty of shelves in convenient places for the 
 numerous boxes and cans which she needs, and there 
 
THE BATHROOM 
 
 281 
 
 should be several closets, one for pots and pans, another 
 for stores of various kinds, and still another cupboard 
 with glass doors for the storage of glass and dishes. The 
 icebox should not be in the kitchen, but in a passageway 
 which leads outside. A small closet, or butler's pantry 
 
 SELVES ^SHCLO.|K 
 
 VENT 
 
 Saving steps in the kitchen. Which arrangement do you prefer ? (After Frederick.) 
 
 as it is often called, may connect the kitchen and the din- 
 ing room. 
 
 The bathroom. The bathroom, though a small room, 
 is surely very important. It has been said that " Cleanli- 
 ness is next to godliness " ; certainly cleanliness is neces- 
 sary for health. The bathroom should have painted or 
 tiled walls which can easily be cleaned. The floor should 
 be tiled or covered with linoleum, and all equipment, 
 
282 MAKING AND BEAUTIFYING THE HOME 
 
 including the bathtub, toilet, bowl, and seat, should be of 
 white enamel ware, so that they may readily be cleaned. 
 There should be ample provision for clean towels, bath 
 sponge, and, if possible, there should be a shower bath. 
 A medicine chest of white enamel ware with glass shelves 
 should complete the equipment of the room. 
 
 Cellar and heating plant. Our ideal home is a de- 
 tached house with a cellar. In the cellar there is storage 
 room for vegetables, canned goods, wood, and coal. The 
 heating plant should be of ample size to heat the house in 
 the severest weather. Probably the best of all types of heat- 
 ers is a combination of hot water and hot air, the hot water 
 pipes heating the rooms in distant parts of the building, and 
 the hot air going to the rooms directly over the furnace. 
 
 The ideal home is not always possible. It is not to be 
 expected that any of us can live up to all of the standards 
 set in the above paragraphs. No one of us has the right 
 to say, " What is the use of trying to have a better 
 home?" even though we cannot live up to the standard 
 set as our ideal. This is not an age of ideal living, but 
 we want to make our standards high. It is well to re- 
 member that an ideal home life is possible even when an 
 ideal house may not be afforded. If one thinks about 
 these matters and tries to improve them good will come 
 from these suggestions. 
 
 The score card. The following score card gives a 
 standard for checking up conditions in your own homes. 
 Some of you will doubtless want to add to or subtract from 
 the items given here. If so, remember that the class wants 
 the benefit of your ideas. So bring your card, with its 
 changes, and put it before the class in an open discussion. 
 Perhaps a much better card than this will result. 
 
SCORE CARD 
 
 283 
 
 SCORE CARD. MY HOME 
 
 
 
 SCORE 
 
 
 
 PER- 
 
 MY S 
 
 C0 
 
 
 SCORE 
 
 
 Total 
 
 The House 
 Type 
 Detached with garden . 
 
 IO 
 
 
 
 Semi-detached back yard . (7) 
 
 
 
 
 Apartment or flat (5) 
 
 
 
 
 Ownership 
 Owned no mortgage 
 
 IO 
 
 
 
 Owned with mortgage (5) 
 
 
 
 
 Rented (3) 
 
 
 
 
 
 
 
 
 Bedrooms 
 Windows (average) 
 Two windows 
 
 IO 
 
 
 
 One window (6) 
 
 
 
 
 No window . . (o) 
 
 
 
 
 Fittings 
 Painted walls, no carpet or heavy hangings, 
 iron bed .... 
 
 IO 
 
 
 
 Any one item lackin^ (8) 
 
 
 
 
 Any two items lacking (4) 
 
 
 
 
 
 
 
 
 Living Room 
 All items mentioned in paragraph, page 279 . 
 At least half items including table, books, com- 
 fortable chairs and couch (5) 
 No items given in paragraph on living room (o) 
 
 10 
 
 
 
 
 
 
 
 Dining Room 
 Pleasant outlook, suitable table and chairs, 
 china closet and dish closet, buffet, room not 
 carpeted, walls plain or inconspicuous figure, 
 table light does not shine in eyes, room 
 clean and tidy 
 Half of items above ... (5) 
 
 IO 
 
 
 
 None of items above (o) 
 
 
 
 
 
 
 
 
 Kitchen 
 Well arranged to save steps, equipped with 
 sink, table, range, tireless cooker, kitchen 
 cabinet or closed closet, hot and cold water, 
 floors and walls easily cleaned 
 
 10 
 
 
 
284 MAKING AND BEAUTIFYING THE HOME 
 SCORE CARD. MY HOME Continued 
 
 
 
 SCORE 
 
 
 
 PER- 
 
 MY < 
 
 )CORE 
 
 
 SCORE 
 
 
 Total 
 
 Kitchen Continued 
 Half of items above (5) 
 
 
 
 
 None of items above ... . (o) 
 
 
 
 
 
 
 
 
 Bathroom 
 Bathtub, shower, toilet and washboard, fittings 
 of porcelain or white enamel, open plumbing, 
 hot and cold water, mirror well lighted, medi- 
 cine cabinet, room well ventilated .... 
 Half of items above (5) 
 
 IO 
 
 
 
 No bathroom (o) 
 
 
 
 
 
 
 
 
 Heating plant 
 Heater for cellar, whole house except bedrooms 
 warm 
 
 IO 
 
 
 
 Stoves in all rooms except bedrooms. Oil 
 stoves for bedrooms . (5) 
 
 
 
 
 Fireplaces or wood stoves only (2) 
 
 
 
 
 
 
 
 
 Repair of home 
 House new, first occupants . . , . . . 
 House new within ten years (7) 
 House over fifteen years old, many previous oc- 
 cupants. Fair repair (5) 
 House over twenty years old. Badly run down (o) 
 
 IO 
 
 
 
 
 GRAND TOTAL 
 
 IOO 
 
 
 
 
 Ginn and Company. 
 Henry Holt and Com- 
 
 REFERENCE BOOKS 
 
 Allen, Civics and Health, Chapters I, II, III (For teachers). 
 Barber, First Course in General Science, Chapters I, II, VI. 
 
 pany. 
 
 Bodmer, The Book of Wonders (Story of Cement). Presbrey Syndicate. 
 Broadhurst, Home and Community flygiene, Chapter XIII. J. B. Lippincott 
 
 Company. 
 
 Child, The Efficient Kitchen (For teachers). McBride, Nast and Company 
 Clark, The Care of a Home (For teachers). The Macmillan Company. 
 
REFERENCE BOOKS 285 
 
 Clark, An Introduction to Science, Chapters XVIII, XXIX. American Book 
 Company. 
 
 Farmers' Bulletin 461, U. S. Dept. Agr. The Use of Concrete on the Farm. 
 
 Farmers' Bulletin, 474, U. S. Dept. Agr. The Use of Paint on the Farm. 
 
 Frederick, Mrs. C., Household Engineering. American School of Household Eco- 
 nomics, Chicago. 
 
 Hunter, A Civic Biology, Chapters XXII, XXIV. American Book Company. 
 
 Morris, Household Science and Arts. American Book Company. 
 
 Portland Cement Association Booklets 26, no, 135, 140. in West Washington St., 
 Chicago. 
 
 Standards, Bureau of, Bulletin 70. 
 
 Van Buskirk and Smith, The Science of Everyday Life, Project XI. Houghton 
 Mifflin Company. 
 
 Van Rensselaer, Manual of Home Making (For teachers and project reading). 
 The Macmillan Company. 
 
CHAPTER XVIII 
 PLANNING THE HOME GROUNDS 
 
 Problems. i. To learn how to make the grounds at- 
 tractive. 
 
 2. Arrangement and color effect of flowers. 
 
 3. To learn how to take care of house plants. 
 
 4. To find cut what plants make a good porch screen. 
 
 Project I. To BECOME A LANDSCAPE GARDENER FOR YOUR 
 
 HOME OR FOR SOME FRIEND'S HOME. 
 
 1. Become familiar with the ground plans of the best kept places 
 in town. 
 
 2. Collect and study plans of home grounds which show location 
 of buildings, paths, driveways, trees, shrubs, flowers, garden and 
 play space. 
 
 3. Apply knowledge to the particular home grounds you desire to 
 improve and estimate cost of the improvements. 
 
 4. Make a report, giving your plans in detail. 
 
 Suggested Projects. 
 
 1. TO PLAN, PLANT, AND CARE FOR A FLOWER GARDEN. 
 
 2. TO MAKE A STUDY OF THE ORNAMENTAL SHRUBS AND TREES 
 
 FOUND IN THE TOWN OR NEIGHBORHOOD. 
 
 3. TO PLAN, PLANT, AND CARE FOR A WINDOW GARDEN. 
 
 Planning the ground. A house needs a setting, just 
 as a beautiful stone in a ring does. Many cozy and at- 
 tractive homes are spoiled by the absence of attractive 
 
 286 
 
PLANNING THE GROUND 
 
 287 
 
 A house without trees or shrubbery. 
 
 shade trees, shrubbery, and vines which might easily be 
 grown around them. The house in the above picture, 
 though a fine one, suffers because it has no attractive sur- 
 roundings. Compare it with the next picture. How much 
 more attractive the second house appears, with its well- 
 shaded lawns, its shrubbery, and its flower gardens. 
 
 The home grounds here are well planned. 
 
288 
 
 PLANNING THE HOME GROUNDS 
 
 The use of trees. Trees are useful as well as orna- 
 mental. They are the homes of many birds. They serve 
 to break the force of strong winds in winter, and give 
 pleasant and cooling shade in summer. Trees give oft" much 
 
 moisture through their 
 leaves. According to 
 Ward, an oak may send 
 off 226 times its own 
 weight in water through 
 a growing season. This 
 moisture helps to cool 
 the air, and makes a 
 more even temperature. 
 But trees should not be 
 so abundant about the 
 house as to shut out all 
 the direct sunlight. A 
 good arrangement, if the 
 place is a large one, is 
 secured by groups of 
 trees which make natu- 
 ral shady places on the 
 grounds, and if the lot is a small one, two or three trees 
 will suffice, planted so that they will not completely shade 
 the house but will give an agreeable setting to it. Fruit 
 trees may be grown even on city lots. 
 
 The use of trees and shrubs in beautifying our grounds. 
 -Landscape gardening has come into the list of pro- 
 fessions of late years, and any one of us may become his 
 own landscape gardener, if a little common sense as well 
 as artistic taste is used. We shall see when we come to 
 take photographs that a picture to be artistic must be 
 
 Small fruit trees yield large returns. 
 
THE USE OF TREES AND SHRUBS 
 
 289 
 
 Well-planned home grounds. 3-4 means three plants of number 4. i. Japanese bar- 
 berry. 2. Bridal wreath. 3. Honeysuckle. 4. Japanese rose. 5. Lilac. 6. Peony. 
 7. Iris. 8. Phlox. 9. Deutzia. 10. Deciduous trees. n. Evergreen trees. 
 (After Moore and Halligan.) 
 
 H.-WHIT. CIV. SCI. IN THE HOME - 19 
 
2QO 
 
 PLANNING THE HOME GROUNDS 
 
 balanced, that is, it must have a certain amount of light 
 and shadow, of prominent foreground and distant back- 
 ground. We must in planning the home grounds re- 
 member that the house is a gem in the setting, and that the 
 setting of trees and shrubs should make our house look as 
 attractive as possible. The walk to the house may be 
 bordered with flowers, tulips, jonquils, or lilies of the 
 valley in the early spring, followed by marigolds, sweet 
 Williams, zinnias, or other old-fashioned border flowers 
 for the summer, and finally asters or chrysanthemums 
 for the fall. Thus we have a constant series of bloom along 
 the walk. The grounds may be rendered still more at- 
 tractive by planting shrubs, such as syringa, a beautiful 
 white blooming, sweet shrub, or weigela, which flowers in 
 June and July, with various shades of red and white, and 
 
 Roses at their best. Ramblers, red and white. 
 
 the Japanese quince. The lilac, which grows rapidly and 
 whose blossoms are known to us as early flowers, and, 
 
THE USE OF TREES AND SHRUBS 291 
 
 of course, roses, both the climbing and bush, should be 
 planted. The hardy hydrangea is perhaps the best shrub 
 
 Climbing vines give privacy. 
 
 for late flowering. When a small tree is desired the 
 Japanese maple or the silver cut-leaf birch will be found 
 to be both beautiful and hardy. For large trees we may 
 choose elms with their graceful, overhanging branches, 
 maples with their splendid coloring in the fall, beeches, 
 and birches, with a few evergreens. 
 
 Nothing is more attractive than a hospitable porch 
 covered with climbing roses and honeysuckle, or other 
 vines, giving a sense of privacy and coolness. Vines are 
 easily planted, and there are many quickly growing ones, 
 such as the moon flower, the climbing ramblers, and the 
 scarlet bean. One of the pleasantest porches imaginable 
 
2Q2 
 
 PLANNING THE HOME GROUNDS 
 
 is one shaded with a fine grapevine. . The leaves give a 
 pleasant coolness, and the purple fruit is a delight in 
 the early autumn. Training trees to climb is very com- 
 mon in Europe, but has not been used so much in this 
 country. 
 
 The indoor garden. Not everybody can have a house 
 with grounds, but it is perfectly possible for all of us to 
 
 An indoor garden is a joy in winter. 
 
 have a garden indoors, not the household plants like bac- 
 teria, yeasts, and mold which may do harm, but a window 
 box of beautiful green flowering plants. The dining room, 
 especially if it has sunlight, is a good place for such a pro- 
 ject. Shelves may be put up in the window, and on these, 
 oblong boxes painted green, or flower pots, can be used. 
 What cheer is brought to a room by a sunny window filled 
 with geraniums, oxalis, fuchsias, and in the early spring, 
 lilies and tulips ! Why not make a home project of the 
 planting and care of such a garden? 
 
PLANNING FOR PLEASURE 
 
 293 
 
 A home vegetable garden. 
 
 Planting for profit. The World War with its need of 
 the conservation of food for shipment to our allies, and 
 supplies of fresh food for the people at home, brought out 
 as nothing else could the value of the home garden. War 
 gardens in this country were estimated in 1918 to have 
 supplied nearly five hundred million dollars' worth of vege- 
 tables, this value equal to about one twelfth of the Fourth 
 Liberty Loan. It was found early in 1917 that there were 
 186,000 vacant lots in New York City, and 5000 acres in 
 Minneapolis, Minnesota, much of which space was avail- 
 able for war gardens, and these figures could doubtless 
 be duplicated in cities from all parts of the country. 
 
 A garden need not be a large one to be profitable. One 
 can raise enough vegetables for a family of four in a city 
 back yard on a plot twenty-five feet by twenty-five feet. 
 It requires planning and a knowledge of soil and other 
 conditions, which will be given in the next chapter. In 
 connection with any home garden we should always plan 
 
294 
 
 PLANNING THE HOME GROUNDS 
 
 to have flowers, and in a city back yard where space is 
 limited, the climbing plants can be trained up the side of 
 the fence. The borders can be filled with plants which 
 mature early and which can be pulled up to make a place 
 for others later. A later study of crop rotation and 
 combination of plants will enable us to undertake this 
 project intelligently. 
 
 Planning for pleasure. Every house lot of any size 
 ought to be planned for pleasure and for profit. We need 
 
 out-of-door exercise in the 
 form of games as well as 
 in the form bf work. 
 Tether ball, Russian nine- 
 pins, volley ball, quoits, 
 or basket ball will give 
 splendid exercise in a 
 limited amount of space, 
 as not over 50 to 200 
 square feet are needed 
 for any of the above- 
 mentioned games. What 
 is better than a good ten- 
 nis court, a croquet lawn, 
 or to be more scientific, a 
 roque court? If we have 
 a barn or garage on the 
 place with a flat wall 
 having no windows, we 
 can with very little ex- 
 pense and trouble make a 
 hand-ball court. And if there is room inside, this can be 
 used both winter and summer, giving us splendid exercise. 
 
 Russian ninepins. Ball must go around a 
 post (to the left of picture but not shown 
 here) before it strikes the pins. Score as 
 in bowling. - - . , 
 
SCORE CARD 
 
 295 
 
 We should all remember that the home to be attractive 
 must be placed where we can have a good time, bring 
 our friends, and make our yards the center of a pleasant 
 group of young people. How many boys who have read 
 this chapter can now go home and plan to add in some 
 way to their store of attractions, both for themselves and 
 their friends ? 
 
 Use of the score cards. We have two score cards for this 
 chapter, one for boys and girls who are fortunate enough 
 to have their own ground to plan for and those who live 
 in communities that are thickly settled. In the latter case 
 the community ought to provide means of recreation and 
 health for all. If your score is not high, then there is 
 something wrong. 
 
 SCORE CARD. MY HOME GROUND 
 
 
 Set 
 
 )RE 
 
 
 Perfect 
 Score 
 
 My 
 score 
 
 Grounds planned for beauty or utility . . . . 
 
 cr 
 
 
 Shade trees grouped 
 
 tr 
 
 
 At least one fruit tree 
 
 r 
 
 
 Porch screened with climbing vines 
 
 c 
 
 
 Well-arranged flower beds 
 
 5" 
 
 
 Flowers from spring until fall 
 
 5" 
 
 
 Flowering and ornamental shrubs . . 
 
 c 
 
 
 Outhouses and garden screened with trees and shrubs . 
 Lawn attractive and well kept. Borders kept trimmed 
 Play space with at least one game in use . . . 
 
 s 
 
 5 
 5 
 
 
 TOTAL 
 
 CQ 
 
 
 
 
 
 The following score card may be used by city children 
 or those who do not have home grounds. 
 
296 
 
 PLANNING THE HOME GROUNDS 
 
 SCORE CARDS. PARKS, PLAYGROUNDS, AND LIBRARIES 
 
 
 
 Sc( 
 
 )RE 
 
 
 
 Perfect 
 Score 
 
 My 
 
 Score 
 
 Public park within half mile of home 
 Within one mile .... 
 
 (r) 
 
 IO 
 
 
 Within two miles 
 
 (7) 
 
 
 
 Parks have ball fields, tennis courts, and golf links 
 Two of above 
 
 (6) 
 
 10 
 
 
 One of above 
 
 (.) 
 
 
 
 Public playgrounds 'within quarter mile from home 
 Within half mile 
 
 *CO 
 
 IO 
 
 
 Within one mile 
 Public baths within one mile of home 
 
 (3) 
 
 IO 
 
 
 Within two miles 
 
 (r) 
 
 
 
 Within three miles .... ... 
 
 CO 
 
 
 
 Public library within half mile of home .... 
 
 
 IO 
 
 
 Within three quarters mile 
 Within one mile . . 
 
 (5) 
 f*) 
 
 
 
 
 
 
 
 TOTAL 
 
 
 ro 
 
 
 
 
 
 
 REFERENCE BOOKS 
 
 Bailey, Encyclopedia of Agriculture (Teachers Article on planning use of grounds, 
 horticulture). The Macmillan Company. 
 
 Hodge, Civic Biology, Chapters I, VIII. Ginn and Company. 
 
 Mayne and Hatch, High School Agriculture, Chapter XIX. American Book Com- 
 pany. 
 
 McKeever, Farm Boys and Girls. The Macmillan Company. 
 
 Moore and Halligan, Plant Production, Chapter XIX. American Book Company. 
 
 Nolan, The Teaching of Agriculture, Chapter IV (Teacher's use). Houghton 
 Mifflin Company. 
 
 Trafton, Science of Home and Community. Houghton Mifflin Company. 
 
 Transeau, Science of Plant Life, Chapter I. World Book Company. 
 
 Van Rensselaer, Manual of Home Making, Chapter I (Teachers). The Macmillan 
 Company. 
 
CHAPTER XIX 
 THE HOME GARDEN 
 
 Problems. i. To understand the nature of different 
 soils. 
 
 2. To learn the value of water and air in the soil. 
 
 3. What are the purposes and methods of cultivation? 
 
 4. To find out what are the important plant foods, and 
 how you would supply them if lacking. 
 
 5. To learn how to force early vegetables. 
 
 Experiments and demonstrations. i. To test a sample of garden soil 
 for acidity with blue litmus. 
 
 2. To show capillarity in gravel, sand, clay, and loam. 
 
 3. To show the effect of cultivation to prevent loss of soil water. 
 
 4. To test the starch-making power of a plant in sunlight and in absence 
 of light. 
 
 Project I. To LEARN WHAT THE SOIL NEEDS FOR ANY PARTICU- 
 LAR CROP. 
 
 i. Does it need humus? 2. Does it need draining? 3. Does 
 it need lime? 4. What are the three principal chemicals found in 
 commercial fertilizers? Which are needed in my garden? 
 
 Suggestion. 
 
 A test to show what chemical elements are most needed is best 
 carried out in plot testing as follows: 
 
 Make seven equal-sized plots, say, 5 feet wide by 25 feet long. 
 
 297 
 
298 
 
 THE HOME GARDEN 
 
 A = i Ib. Sodium Nitrate 
 B = i Ib. Potassium Sulphate 
 C = 2 Ib. Acid Phosphate 
 
 On plots i, 4, and 7, use no fertilizer whatever; on plot 2, use 
 A, B, C; on 3, use B and C; on 5, use A and B; on 6, use A and C. 
 
 Plant same amount of seeds on each 
 plot; give all same care. Compare 
 crops from each plot to decide the 
 fertilizer most needed by the soil for 
 that particular crop. 
 
 NO FERTILIZER 
 
 1 
 
 A, B AND C 
 
 2 
 
 B AND C 
 
 3 
 
 NO FERTILIZER 
 
 4 
 
 A AND B 
 
 5 
 
 A AND C 
 
 6 
 
 NO FERTILIZER 
 
 7 
 
 Suggested Projects. 
 
 1. TO PLAN, PLANT, AND TAKE 
 CARE OF THE VEGETABLE GARDEN. 
 
 2. TO MAKE AND USE A HOTBED OR 
 A COLD FRAME. 
 
 3. MAKE A COLLECTION OF DIF- 
 FERENT TYPES OF SOILS FOUND IN 
 
 YOUR NEIGHBORHOOD, KEEPING A RECORD OF THE KIND OF VEGETA- 
 TION OR LACK OF PLANT LIFE FOUND IN EACH LOCALITY. 
 
 Science and the home garden. " What do I want 
 to know about science in taking care of my home gar- 
 den? " - might be the remark of a boy who has had some 
 gardening experience. He has grown vegetables and 
 flowers without any more knowledge than the common 
 sense that he has picked up from older people or read in 
 books or garden magazines. It is true that a person might 
 have a flourishing garden and know very little about the 
 scientific principles necessary to understand the soil and the 
 life of the plants living in it. But when we consider that 
 plants are living things, that they require certain " plant 
 foods " or raw food materials, and that they must be pro- 
 vided with what they most require in order to grow to their 
 
WHAT IS SOIL? 
 
 299 
 
 full size, then we can at once see the real reason for know- 
 ing some science. How otherwise could we improve the 
 yield in our gardens? If we do not know about the com- 
 position of soil, the principles underlying crop rotation, the 
 reasons for the use of certain fertilizers, or the different 
 ways of handling soil, then it is not likely that we shall get 
 as much out of our home garden as the boy or girl who 
 
 Cultivating the home garden. 
 
 does have this knowledge. The following pages will help 
 us to apply our knowledge of science to the project of mak- 
 ing our home garden more productive. 
 
 What is soil ? We have already learned that soil is 
 composed largely of inorganic material, as powdered rock, 
 and that it usually contains organic material which has 
 come from the decay of plants and animals. Most of us 
 say that dark soil is rich, meaning that it has a great 
 deal of organic material in it. Soils, as we know, may be 
 
300 
 
 THE HOME GARDEN 
 
 sandy or clayey, and thus we sometimes speak of them as 
 light or heavy ; a heavy soil holds water. 
 
 Experiment. To test a sample of garden soil for acidity. 
 
 Materials: Blue litmus paper. Some acid, as hydrochloric acid, vinegar, 
 or lemon juice. Quicklime. 
 
 Method: Observe the effects of acids upon blue litmus paper by wetting 
 litmus paper with some dilute acid. Vinegar or lemon juice may be 
 used. What color change is observed ? This is caused by acids. Wet 
 a sample of garden soil with water. Lay the blue litmus paper into 
 this, and let it remain for a short time. Examine to see if there is a 
 color change which indicates the presence of an acid. If the soil is 
 found to be acid, add a small quantity of powdered lime and mix 
 thoroughly. After twenty-four hours test for acidity. What is the 
 result? What is one way of correcting acidity in the soil? 
 
 Water in the soil. You are all familiar with the fact 
 that coffee creeps up on the lump of sugar placed partly 
 in it, and that oil rises in the lamp wick. This rise of 
 fluids against the force of gravity is called capillarity. 
 Soil, as the diagram shows, if examined under a magnify- 
 ing glass would be found to be made up of millions of par- 
 ticles of different sizes, each particle holding around it a 
 little film of water. Water rises through the spaces be- 
 tween soil particles by 
 capillary action, and 
 thus is held in the soil 
 not far from the surface. 
 
 Experiment. To show capil- 
 larity in gravel, sand, clay, 
 . and loam. 
 
 Materials: Four large glass 
 tubes, or cylindrical lamp 
 chimneys. Dry sand, 
 coarse and fine. Dry powdered clay. Dry loam. A rack to sup- 
 
 The soil particles are each surrounded by a film 
 of water. 
 
 port the tubes. Basin. Cheesecloth. 
 
EFFECTS OF CULTIVATION ON SOIL 301 
 
 Method: Tie two thicknesses of cheesecloth over the bottoms of the 
 tubes. Fill the tubes respectively with coarse sand, fine sand, clay, 
 and loam. Support the tubes so that their lower ends are half an inch 
 above the bottom of the basin. Pour water in the basin to a depth 
 of one inch. 
 
 Observation and Conclusion: Compare these soils in the rapidity with which 
 the water rises and the height which it finally reaches. Which soil 
 can take the water the greatest distance above the water table? 
 
 Air in soil. This same loose, porous structure of the 
 soil allows a certain amount of air to remain in the spaces. 
 Plants breathe, and need the oxygen of the air just as 
 much as we do. And since the delicate roots of plants 
 absorb air as well as water, porosity of soil is very necessary 
 for the garden. 
 
 Experiment. To show the effect of cultivation in preventing loss of soil 
 water. 
 
 Materials: A box about 8 inches by 14 inches by 4 inches, filled with 
 garden soil. Two glass tumblers. 
 
 Method: Let the box with soil stay out of doors until after a good rain, 
 then bring it into the house. The rain has made the soil compact. 
 After the surface appears dry 'rake the surface of one half of the box with 
 a fork to loosen the surface soil particles, making a loose, dry mulch. 
 Place one glass, mouth down, over the untouched surface, and the 
 other glass over the raked surface. Let the box stand in the sun for 
 an hour or so. Compare the amount of water that condenses on the 
 two glasses when they have cooled down a little. 
 
 _ Conclusion: Does this experiment give you any evidence regarding the 
 method of conserving soil moisture? 
 
 Effects of cultivation on soil. In order to keep the soil 
 broken up so that it may not become packed too firm 
 and hard, thus preventing water and air from passing 
 readily through it, we cultivate, or break up the top layer 
 of the soil either by hoeing, raking, harrowing, or by means 
 of a cultivator. Cultivation crumbles the soil, and allows 
 the plant roots to creep through it more easily. It breaks 
 
302 
 
 THE HOME GARDEN 
 
 up the soil particles so that water can soak out the ma- 
 terials which the plants use for food. It allows the air to 
 
 Cultivation in the Central West. 
 
 pass through the soil, and by making a loose mulch or 
 broken surface (see diagram below) water is more easily 
 kept in the garden soil. 
 
 PLOWED SOIL 
 
 I NOT-.: HARROWED 
 
 .SUBSOIL -MSppp jalte,' SUBSOIL f 
 
 HH I 
 
 A B 
 
 A, Soil as left by the harrow. B, The same soil packed by rain. (After Mayne 
 and Hatch.) 
 
 Mineral materials in the soil. While soils differ a good 
 deal in their mineral content, there are certain min- 
 
HOW PLANTS TAKE WATER OUT OF THE SOIL 303 
 
 AH food, elements - d tut - eituJtr 
 
 Result of test to show need of mineral foods. 
 
 erals that must be present in small quantities in order 
 that plants may grow. Living matter is a very com- 
 plex substance. We 
 cannot give the exact 
 proportion of its ele- 
 ments, but we know 
 that it contains a large 
 portion of carbon, hy- 
 drogen, oxygen, nitro- 
 gen, and a much smaller 
 portion of calcium, sul- 
 phur, potassium, mag- 
 nesium, phosphorus, so- 
 dium, and chlorine. It 
 would be very easy to 
 show by growing plants 
 
 in water containing solutions of these mineral materials, 
 that they will not live if certain of these ingredients are 
 not found in the water which they absorb. 
 
 How our plants take water out of the soil. If you 
 examine some growing radish or mustard seedlings you 
 find that the roots of the tiny plants are covered with a 
 
 fringe of white, 
 hairlike structures. 
 These are called 
 root hairs. They 
 are long cells pro- 
 jecting from the 
 sides of the root, 
 and are the ab- 
 sorbing organs of 
 the plant. The 
 
 Diagram of a root hair : CS, cell sap ; CW, cell wall ; 
 P, protoplasm ; N, nucleus ; S, particles of soil. 
 
304 THE HOME GARDEN 
 
 outer portions of the roots of most plants are provided with 
 these little structures, so that water is constantly being taken 
 by absorption. Since plants pass off many times their own 
 weight of water by evaporation through their leaves during 
 the growing season, the root hairs must have a very con- 
 siderable work to do. We shall not try to show now how 
 they take the water in. It is sufficient to know that water 
 with its soluble mineral salts passes from these root hairs 
 up through the roots and stems to the leaves where, as we 
 shall see, it is used in making living matter and food for 
 the plant. 
 
 The root hairs take more than water out of the soil. 
 If a root possessing root hairs is washed carefully, it will be 
 found to have little particles of soil still clinging to it. These 
 particles of soil seem to be cemented to the sticky surface 
 of the root hair. Root hairs give off an acid. Sometimes 
 soils become too acid. Lime added to such soils helps to 
 neutralize the acid and make them fit for garden use. Acids 
 in the soil help dissolve some of the mineral substances. 
 The resulting solutions mixed with soil water are absorbed 
 by the root hairs. There is also much mineral matter 
 from the soil dissolved in water without the aid of the 
 acid, which is taken up by the root hairs. 
 
 Plants take nitrogen from the soil. One very neces- 
 sary element in the composition of living matter is nitro- 
 gen. Nitrogen makes up nearly four fifths of the air 
 around us, and yet it is not available for use by plants 
 until certain bacteria In the soil have acted on it. Some 
 of these bacteria live in little nodules or lumps on the 
 roots of clovers, peas, beans, and other plants called le- 
 gumes and have the power in some mysterious way to take 
 some of this nitrogen out of the air and fix it so that it 
 
REASONS FOR ROTATION OF CROPS 
 
 305 
 
 becomes usable in the soil as plant food. Nitrogen in the 
 bodies of dead plants and animals also is acted upon by 
 the bacteria which cause decay, and is eventually made 
 into soluble mineral substances called nitrates. The 
 changes through which 
 nitrogen passes are too 
 complex for us to ex- 
 plain at present, but we 
 should remember that 
 in all the world it is in 
 circulation, from the 
 bodies of living plants 
 and animals, to the soil, 
 there to be changed into 
 soluble nitrates which 
 may be absorbed by the 
 roots and used by the 
 plants again. 
 
 Reasons for rotation 
 of crops. It is com- 
 mon knowledge among 
 boys and girls who have 
 had gardens that the soil 
 
 " wears out " after a while, and that it becomes necessary 
 either to add manure, which contains nitrogen in a usable 
 form, or some artificial fertilizer which contains nitrates, 
 phosphates, or potash. By raising peas, alfalfa, or clover, 
 we can often bring back the soil to its former state of 
 fertility. A boy who wishes to get the most out of his 
 garden will rotate the crops, or make a combination plant- 
 ing. This enables him to get much more out of his garden 
 than if he planted only one crop. A good combination for 
 
 H.-WHIT. CIV. SCI. IN THE HOME 2O 
 
306 THE HOME GARDEN 
 
 two crops in a year would be early peas followed by toma- 
 toes, squash, or sweet corn ; or radishes, lettuce, or spinach 
 followed by lima beans, string beans, or carrots ; or string 
 beans followed by celery, cabbage set out from plants, 
 beets, or turnips. In which of these plantings do we get 
 nitrogen provided for the soil ? 
 
 How plant food is changed into living material and food 
 for animals. A simple experiment would convince you 
 that certain garden vegetables contain foods. If you take 
 carrots, peas, beans, radishes, turnips, potatoes, or any 
 other vegetables you may choose, and test each of them 
 for starch, for sugar, and for protein (see Chapter VI), you 
 will be able to prove the presence of these food materials. 
 How did they get there? They were not in the soil 
 and they were not in the seeds in large enough quanti- 
 ties to make the amounts we find when we gather the 
 vegetables. We know the plants made them, but how? 
 
 Experiment. To test the starch-making power of a plant in sunlight and 
 in the dark. 
 
 Materials: A green plant. Black alpaca cloth. Wood alcohol. Iodine. 
 
 Method: Place any small green plant in a dark room for 24 hours. Then 
 cover parts of several different leaves with strips of black cloth. Ex- 
 pose to direct sunlight for an hour or more. Pick the leaves which 
 were covered, take off the cloth, and place the leaves in hot wood 
 alcohol to dissolve the green coloring matter. When free from green 
 color, wash the leaves and place them in a solution of iodine to test for 
 starch. 
 
 Observation: What evidence do you find in regard to the presence of 
 starch in any part of the leaf? 
 
 Conclusion: Why do we place the plant in the dark at the beginning of 
 this experiment? What effect does sunlight have upon green leaves? 
 How do you know? What effect does absence of light have? 
 
 The leaf a food manufactory. This experiment shows 
 us that the green leaves of plants act as factories, in which 
 
A HOME GARDEN PROJECT 
 
 307 
 
 sunlight with its energy is the power that runs the factory. 
 The green coloring matter in the leaf, under the influence 
 of sunlight, takes carbon dioxide from the air and water 
 from the soil, and changes them into sugars and starches. 
 It uses the mineral salts and carbon compounds to make 
 proteins, and the living matter from 
 which the plant is formed. ' Each 
 one of us, eating food which plants 
 have formed, may make living 
 matter of it, or if we prefer a mixed 
 diet of animal and plant food, we 
 take the flesh of some animals 
 which have lived upon food manu- 
 factured by green plants. In 
 either case the food was originally 
 made by plants, hence food supply 
 ultimately depends on plants for its 
 source. 
 
 A home garden project. We know that the soil must 
 be well watered, and we know that we need sunlight in 
 order to have a successful garden. We therefore choose 
 a slope which faces south so as to get as much light as 
 possible, and an area free from trees. Take a square 
 ruled sheet of paper ; five squares to the inch is a con- 
 venient ruling. Lay out the garden according to the area 
 you have. Mark the borders with green crayon. Put in 
 flower beds, using the colors of the flowers, also show the 
 position of any fruit trees, or shade trees, grape vines, or 
 the like. Mark off your space for vegetables, putting 
 green or other colored dots to show the position of dif- 
 ferent plants. Use the suggestions in table (p. 311) for the 
 distances apart for planting your vegetables. Make plans 
 
 Starchless area in a leaf caused 
 by excluding sunlight by 
 means of a strip of black 
 cloth. 
 
THE HOME GARDEN 
 
 Oxygen 
 
 for crop rotation, using a second sheet of paper, which may 
 be placed alongside of the first. Keep your plans for future 
 work in the garden. Such plans could be made in early 
 spring or in the winter, and would help greatly when you 
 
 come to work the 
 ground. Keep a record 
 of the approximate dates 
 of planting the differ- 
 ent vegetables, and the 
 number of rows or hills 
 to be planted. Later, 
 when vacation comes, 
 and you are planting 
 your garden, you will 
 be surprised to see how 
 useful these directions 
 are. 
 
 Use of the cold frame 
 and the hotbed. An 
 excellent home project 
 would be the construc- 
 tion of a hotbed or cold 
 frame. Cold frames en- 
 able us to get a much 
 longer period for grow- 
 ing vegetables. In the 
 early spring they are 
 especially useful to raise parsley, lettuce, and radishes for the 
 table. They also give tender plants as tomatoes and pep- 
 pers protection from the cold. A cold frame could easily be 
 manufactured by taking an old storm window or any 
 small window as a top, and fitting it over a frame made 
 
 *& A typical leaf 
 SF r~ 'cell producing 
 VstarcK(CH(5), 
 /rom the elements 
 / HOandCO 
 
 Carbon dioxide/rom 
 tTie air reaches cells 
 througH lower surface, 
 A cfiv^d 7 
 
 va 
 
 J bundles 
 gives th 
 element: 
 H,0. 
 
 Water tctloe-rx 
 lay root, 
 
 matter also 
 "by 
 
 Diagram to illustrate the formation of starch in 
 a leaf. 
 
USE OF THE COLD FRAME AND THE HOTBED 309 
 
 of boards nailed together to form a rectangle. The frame 
 is simply a box without a bottom, set into the ground. 
 Prepare the soil in this box with special care, using manure, 
 
 ENERGY FROM SUN 
 
 \ 1 / 
 
 ENERGY SEt FREE AS HEAT 
 
 THESE- TEAR- LOwjN AMMO niA 
 MPLEX ORGANIC SU 
 TANCES AND SET F&E 
 
 AMMON1A|E> UII ' I> 
 
 (NI ^) > |OR<^ANIC SUBSTA 
 
 (H 2 0) 
 
 (H 2 0) 
 
 CA15BO 
 
 (C0 2 ) 
 
 CARBON DIOXIDE 
 (CO*) 
 
 The relation between green plants and animals. 
 
 and breaking the soil up into fine particles. Seeds planted 
 under glass will grow rapidly because of the heat which 
 is retained by it, and if the frames are covered up with 
 
 Cold frame. 
 
 thick cloths or blankets at night, plants may begin to 
 grow two months earlier in the spring and continue two 
 months later in the fall. The hotbed is a deeper box hav- 
 
310 THE HOME GARDEN 
 
 ing a bed three feet deep. The lower part is filled with 
 manure, which is allowed to heat and then is reopened, 
 being tested from day to day until it comes to a tempera- 
 ture of eighty degrees Fahrenheit. Cucumbers, lettuce, 
 muskmelons, and tomatoes may be started in the hotbed, 
 and later transferred to the outside. To have the hot- 
 bed work successfully, it should be banked on the outside 
 
 Cross section of a hotbed. (After Moore and Halligan.) 
 
 with manure in order to keep the heat in, and remember 
 to cover it at night in cold weather with old rugs or mats 
 in addition to the sash. The table on the next page 
 gives some useful information for planting your own 
 garden. 
 
 Score card of my home garden. It is not in the coun- 
 try alone that school gardens nourish. Very many city 
 boys and girls have an opportunity to. compete with coun- 
 try boys and girls in the home garden project. It will 
 interest you all to know that if you score high in this project 
 you ought to belong to the United States School Garden 
 Army. Perhaps you do and perhaps you have already 
 received an award from them. If not, why not try for it 
 next summer ? The note found under the title of the score 
 card will give you the address to which you may write 
 for directions. 
 
SCORE CARD OF MY HOME GARDEN 
 
 PLANTING AND SEED TABLE FOR VEGETABLES FOR THE HOME 
 GARDEN 
 
 From Bulletin, "The Home Vegetable Garden." by C. W. Waid, Michigan Agricultural 
 
 College. 
 
 NAME OF 
 VEGETABLE 
 
 DATE OF 
 PLANTING 
 
 H 
 
 w M 
 P 
 
 < 
 
 H 
 PO 
 
 DISTANCE 
 APART 
 OF Rows 
 
 (inches) 
 
 DISTANCE APART 
 OF PLANTS IN 
 Rows 
 (inches) 
 
 O &*~' 
 
 ^ 
 
 45-65 
 50-80 
 60-85 
 95-120 
 90-105 
 
 100-150 
 75-no 
 100-130 
 120-130 
 130-150 
 
 65-90 
 
 60-80 
 150-160 
 90-130 
 
 90-120 
 60-80 
 60-90 
 120-150 
 
 25-50 
 130-150 
 90-120 
 125-160 
 40-80 
 
 65-90 
 100-140 
 80-100 
 100-140 
 100-140 
 
 30-40- 
 35-50 
 75-100 
 
 ! 20-1 80 
 
 30-60 
 
 60-125 
 120-130 
 100-140 
 60-80 
 100-150 
 
 > Seeds, 
 first crop 
 
 2 Plants, 
 first crop 
 
 Hand culti- 
 vation 
 
 Hills 
 
 Drills 
 
 Beans, bush . . 
 Beans, pole . . 
 Beets .... 
 Brussels sprouts . 
 Cabbage, early . 
 
 Cabbage, late 
 Carrots .... 
 Cauliflower . . 
 Celery, early . . 
 Celery, late . . 
 
 Corn, early . . 
 Corn, late . . . 
 Cucumbers . . 
 Eggplant . . . 
 Endive .... 
 
 Kale .... 
 Kohl-rabi . . . 
 Lettuce . . . 
 Muskmelon . . 
 Okra .... 
 
 Onion, sets . . 
 Onion, seeds . . 
 Parsley .... 
 Parsnips . . . 
 Peas, early . . . 
 
 Peas, late . . . 
 Peppers . . . 
 Potatoes, early . 
 Potatoes, late 
 Pumpkins . . . 
 
 Radishes, early . 
 Radishes, medium 
 Rutabaga . . . 
 Salsify .... 
 Spinach . . . 
 
 Squash .... 
 Sweet potatoes . 
 Tomatoes . . . 
 Turnips . . . 
 Watermelons . . 
 
 'May 
 'May 15-31 
 'April 15-30 
 2 May 
 2 April 15-30 
 
 2 May 
 'May 
 
 2 April 15-30 
 
 1-2 
 1-2 
 4-f 
 
 "i : i" 
 
 F 
 
 1-2 
 1-2 
 
 B 
 
 24-3 
 
 i 
 
 2f-3 
 24-5 
 3-5 
 
 24-3 
 
 4-6 
 
 sR 
 4-6 
 
 t-l 
 
 
 24-3 
 2|-3 
 
 24-3 
 
 6-ic 
 
 IB 
 
 .g 
 
 2 6- 8 
 
 18-30 
 24-36 
 18-24 
 18-30 
 18-30 
 
 18-30 
 18-24 
 18-30 
 18-30 
 18-60 
 
 24-36 
 24-36 
 48-60 
 24-36 
 12-18 
 
 18-30 
 18-30 
 
 12-18 
 
 48-60 
 
 18-30 
 
 12-18 
 12-18 
 12-18 
 
 18-24 
 18-30 
 
 24-36 
 18-30 
 18-30 
 24-30 
 72-96 
 
 12-18 
 
 12-18 
 18-24 
 18-24 
 18-24 
 
 36-96 
 
 24-36 
 24-36 
 18-24 
 
 6072 
 
 8-12 
 18-30 
 
 
 
 2-3 
 
 18-24 
 12-18 
 
 18-24 
 
 3-4 
 
 "W 
 
 8-10 
 
 IO-I2 
 
 12-18 
 12-18 
 
 8-15 
 6-8 
 
 4-12 
 
 1 2-1 8 
 
 .PI 
 
 6-10 
 
 3^4 
 Drilled 
 
 Drilled 
 
 18-24 
 
 18-24 
 24-36 
 48-60 
 24-36 
 
 12-18 
 
 "48-60" 
 18-30 
 
 'May 1-15 
 'May 15-31 
 'May 15-31 
 2 May 20-31 
 2 April 20-30 
 
 'May 
 
 2 May 1-15 
 1 April 15-30 
 'May 15-31 
 2 May 15-31 
 
 1 April 15-30 
 'May 
 'April 15-30 
 'May 
 'April 15-30 
 
 'May 1-15 
 2 May 15-31 
 'April 15-30 
 'May 
 'May 15-31 
 
 'April 15-30 
 'May 
 'April 15-30 
 'May 1-15 
 'April 15-30 
 
 'May 15-31 
 2 May 15-31 
 2 May 15-31 
 'Anril 15-30 
 'May 15-31 
 
 15-18 
 9-15 
 
 I 2-1 8 
 
 72-96 
 
 2-3 
 
 1 
 
 w 
 
 Drilled 
 Drilled 
 6-10 
 3-4 
 4-6 
 
 14-18 
 
 
 36-84 
 18-36' ' 
 
 60-72 
 
 
3 I2 
 
 THE HOME GARDEN 
 SCORE CARD. MY HOME GARDEN 
 
 SCORE 
 
 Perfect 
 Score 
 
 My 
 Score 
 
 General appearance 2 
 
 Arrangements of rows 3 
 
 Freedom from weeds 3 
 
 Cultivation and care 2 
 
 Choice of vegetables 
 
 For home use 5 
 
 For canning 5 
 
 Freedom from pests 
 
 Spraying for insects or disease when needed .... 5 
 
 Other remedial measures if needed ....... 5 
 
 Evidences of 
 
 Continuous cultivation . -. . . . . . . . . . 3 
 
 Crop rotation 'y . , . . . . 2 
 
 Care of tools 
 
 Value of produce 
 
 Used at home 4 
 
 Sold in the market . . . 2 
 
 Used for canning 2 
 
 Accuracy of garden records 2 
 
 TOTAL 50 
 
 REFERENCE BOOKS 
 
 Duncan, Home Vegetables and Home Fruits (For garden project). Charles Scribner's 
 
 Sons. 
 Corbett, The School Garden, U. S. Dept. Agriculture, Bulletin 218, also Farmers' 
 
 Bulletins 154, 255, 408. 
 Garden Manual, U. S. School Garden Army, Bureau of Education, Washington, 
 
 D. C. 
 Food Supply in Families of Limited Means. League for Preventive Work, Boston, 
 
 1917. 
 
 1 Modified from General Leaflet No. 10, United States School Garden Army, 
 Bureau of Education, Washington, D. C. 
 
REFERENCE BOOKS 313 
 
 Hunter, A Civic Biology, Chapters VI, VII. American Book Company. 
 
 Hunter, Laboratory Problems in Civic Biology, Chapters VI, VII. American Book 
 
 Company. 
 Jackson and Daugherty, Agriculture through Laboratory and School Gardens. Orange 
 
 Judd Company, N. Y. 
 
 King, The Soil (For teachers). The Macmillan Company. 
 Lyon, Soils and Fertilizers (For teachers). The Macmillan Company. 
 Mayne and Hatch, High School Agriculture, Chapter II. American Book Company. 
 Moore and Halligan, Plant Production, Chapter XIII. American Book Company. 
 Rexford, The ABC of Gardening (Flower gardens). Harper and Brothers. 
 Spellman, Farm Science, Chapter IV. World Book Company. 
 Trafton, Science of Home and Community. The Macmillan Company. 
 Transeau, Science of Plant Life, Chapter IV. World Book Company. 
 The Small Vegetable Garden, U. S. Dept. Agriculture, Farmers' Bulletin 818. 
 U. S. Food Administration, Food and the War, Chapter XIII. Houghton Mifflin 
 
 Company. 
 War Garden and the Storage of Vegetables, Victory Edition 1919. National War 
 
 Garden Committee, Washington, D. C. 
 
CHAPTER XX 
 PLANT FRIENDS AND PLANT PESTS 
 
 . Problems. i. To learn something about the work of 
 microorganisms in the soil. 
 
 2. To discover how fungi injure plants. 
 
 3. To know the life history of common insect pests. 
 
 4. To find out something of the value of birds to our gar- 
 dens. 
 
 5. To learn how to safeguard the garden against ravages 
 of pests. 
 
 Experiments and demonstrations. i. To show the life history of a 
 moth and a butterfly. 
 
 2. To learn to recognize insects that frequent flowering or garden plants. 
 
 3. To illustrate the proper way of making some insecticides, fungicides, 
 and sprays. 
 
 Project I. To ELIMINATE THE PLANT PESTS FROM MY HOME 
 GROUNDS. 
 
 1. Learn the habits and something of the life history of the pests 
 which appear. 
 
 2. Learn what pests are most likely to attack each kind of plant 
 on the grounds. 
 
 3. Learn when to apply sprays most effectively and about other 
 devices that may be used to prevent or destroy the pests. 
 
 4. Learn how to prepare and to apply the sprays, etc. 
 
 5. Report all your efforts in fighting plant pests through an en- 
 tire summer, showing to what extent your garden benefited. 
 
THE LIVING THINGS IN THE SOIL 
 
 315 
 
 Suggested Projects. 
 
 1. TO ATTRACT AND PROTECT HELPFUL BIRDS. 
 
 2. TO MAKE A COLLECTION OF INSECTS AND CLASSIFY THEM, MAK- 
 ING AT LEAST ONE EXHIBIT FROM EACH OF THE IMPORTANT ORDERS. 
 
 The living things in the soil. Life in this world con- 
 sists of a great deal of give and take. We could not get 
 along comfortably 
 at home without 
 giving in to our 
 brothers and sis- 
 ters, and without 
 helping mother and 
 father, for we take 
 so much in return 
 from them. In the 
 plant and animal 
 world similar con- 
 di tions exist. 
 Plants could not 
 get along without 
 dead organic mat- 
 ter. We have seen 
 the need of man- 
 ure and other de- 
 cayed materials. 
 Garden soil must be thought of as a place where mil- 
 lions of bacteria and other plants and animals live, some 
 friendly and some unfriendly to the plants which are de- 
 sired in the garden. If we were to examine soil for the 
 presence of bacteria, we would find many more in rich 
 soil -than in sandy soil, and very many more near the sur- 
 face than a little distance farther in the ground. Most 
 
 This shows how organic matter is broken down by bac- 
 teria so it may be used again by green plants. 
 
3 i6 
 
 PLANT FRIENDS AND PLANT PESTS 
 
 bacteria are found within six inches of the surface. An 
 examination of sandy soil has shown something like 100,000 
 bacteria to the gram ; in the soil of an ordinary garden, 
 1,500,000 to the gram, while in the soil surrounding privies 
 and cesspools, as many as 115,000,000 to the gram may be 
 found. 
 
 Bacteria in the soil break down organic material, such 
 as dead bodies of plants and animals, and help to oxidize it. 
 
 Some nitrifying bacteria 
 act upon ammonia (a 
 product formed in de- 
 caying) and change it 
 to nitrites, while others 
 change these nitrites to 
 nitrates, which can be 
 used by plants. Still 
 other bacteria, as we 
 have seen, are found liv- 
 ing upon the roots of 
 certain plants, such as 
 
 The nitrogen cycle. Follow the arrows and find clovers, peas, and beans, 
 out what becomes of the nitrogen. . .. 
 
 Sometimes a good farmer 
 
 buys these bacteria and puts them into the soil, or inocu- 
 lates his soil. These bacteria, although they live at the 
 expense of the plants to which they attach themselves in 
 little nodules, yet take the nitrogen out of the air which 
 is held in the soil, and change it into a form that can be 
 used by the plants. In the end the bacteria have reduced 
 nitrogenous substances to a soluble form which can be 
 absorbed through the roots-. There are many other kinds 
 of bacteria present in the soil, some useful, and some 
 harmful. The denitrifying bacteria which are commonly 
 
U 1 Jrii^K 1-lAKiY.i U.L Jf JLAXN 1 & 
 
 3*7 
 
 Inocul 
 
 en fixing bacteria, 
 lligan). 
 
 found in acid soils release the nitrogen in the soil to 
 the air. Are these useful or harmful? Why? In some 
 soils, a little one- 
 celled animal is 
 found which feeds 
 upon useful bac- 
 teria, thus de- 
 stroying the fer- 
 tility of the soil. 
 Many insects in 
 the larval or pu- 
 pal form (page 
 134) make their homes in the earth, and sometimes do much 
 harm by eating the roots of plants. Earthworms, however, 
 are useful animals in the garden, for they plow up the 
 
 ground by boring their holes, thus 
 passing much soil to the surface of 
 the garden through their bodies. 
 This loosens the compact soil 
 and allows water to make its way 
 through the ground. Sometimes 
 we find moles and other boring 
 animals which do harm. 
 
 Other harmful plants. While 
 green plants make food for them- 
 selves, and for the world about 
 them, other little plants do a great 
 deal of harm. Some of these are 
 called fungi. Among them are 
 
 Corn smut. Black knot. * 6 
 
 (After Mayne and Hatch.) molds, TUStS, Smuts, SCabs, and 
 
 many other plant diseases. We find, for example, rust on 
 asparagus, beans, and some other plants* Black rot is an- 
 
PLANT FRIENDS AND PLANT p] 
 
 other plant enemy which grows upon beets and cabbages. 
 Blights are formed on celery, cucumbers, and tomatoes, 
 and other garden vegetables. Still another serious plant 
 enemy is the scab of potato. All these fungi live at the 
 
 expense of various 
 plants, and make them 
 wilt, or the leaves curl 
 up, or some other symp- 
 tom of disease occurs 
 This book does not teL 
 you exactly how to 
 distinguish the various 
 plant diseases. That 
 should be a home proj- 
 ect of your own, and 
 there are many excellent 
 pamphlets published by 
 your state or the Department of Agriculture to which you 
 can refer. For all of these fungous diseases, a very excellent 
 cure is Bordeaux mixture, which is best applied in a spray. 
 Light in relation to fungous growth. We must remem- 
 ber that fungi do not like light, and therefore the garden 
 which is very well shaded and too moist makes a favora- 
 ble place for them to grow. We should never have trees, 
 or many bushes, planted around our garden, for not only 
 do these larger plants take a great deal of " plant food " 
 from the soil, but they may do considerable harm also 
 by shading young growing plants. 
 
 Insect pests. Everybody who has had a garden of his 
 own knows that sooner or later he must expect to find 
 insects doing damage there. The insect damage to all 
 kinds of living trees and plants in the United States in a 
 
 Sample* of Bordeaux mixture. Two and 
 bow Btde ttUtiftc and are the beat. 
 
now TO msTiNdUisii INSISTS 
 
 319 
 
 single year is cst im;itcd ;il one billion dollars. Since we 
 must expect insect pests the best way to prevent damage 
 is to watch for them, and to get rid of them before 
 they become numerous. If we remember that most in- 
 sects lay their eggs on the plants which will later become 
 their food, we can be on the watch for their eggs, and re- 
 move them before harm is done. 
 del the habit, of looking for 
 pests while weeding and culti- 
 vating your garden. The to- 
 mato " worm," for example, 
 usually appears singly, and if 
 picked off early a great deal of 
 damage will be prevented. 
 
 How to tell an insect. We 
 are all familiar with insects, yet 
 how many boys and girls can tell 
 exactly how to distinguish them 
 from other animals ? If we study 
 the diagram of a bee shown 
 here, we find that its body has 
 three parts, the head, the middle 
 pdrtion or the thorax, and the hind portion called the ab- 
 domen. The insect has six jointed legs and may or may 
 not have wings. By the above characteristics you can al- 
 ways distinguish an insect from other animals. 
 
 Experiment. To itudy the life history of a moth and a butterfly. 
 
 a. Eggs 
 
 Method and Observations: In the field look on the under side of leaves 
 for tiny ovoid structural (eggs) of moths and butterflies. The eggs 
 of the cabbage butterfly may be found at almost any time on the under 
 side of cabbage leaves. 
 Conclusion: Why are the eggs laid on the wider aide of certain leaves? 
 
 ab. 
 
 An iniect viewed from the tide. 
 Notice the head, thorax, and ab- 
 domen. What other characters 
 do you find ? 
 
320 PLANT FRIENDS AND PLANT PESTS 
 
 b. Larva or Caterpillar 
 
 Observations: Note that, besides true jointed legs, the caterpillar has 
 others called prolegs. How many true legs are there and where are 
 they located? How many prolegs are there? Locate the spiracles 
 or breathing holes. Remember where they are located on an adult 
 insect. Watch the caterpillar when it feeds. What kind of mouth 
 parts does it have? Might it do damage to plants? How? * 
 
 Conclusion: i. Is a caterpillar a worm? (Look in a biology for the 
 characteristics of worms.) 2. How might the larvae of moths or 
 butterflies be of economic importance ? 
 
 c. Pupa 
 
 Materials: Cocoons of several species of moths with twigs or other parts 
 attached should be furnished for this exercise. 
 
 Note : Moths spin a cocoon for themselves at this stage. Butter- 
 flies spin no cocoon but form a chrysalis. 
 
 Observations: Where do you find the cocoon or chrysalis? Of what dees 
 the cocoon seem to be composed? (The cocoon of the Cecropia is 
 excellent for this purpose.) In a chrysalis locate by means of the body 
 markings the head, antennae or feelers, eyes, wings, legs, and spiracles. 
 Are all the parts of an adult present ? 
 
 Open a cocoon. What do you find inside ? How do you explain this ? 
 
 Conclusion: Making use of all the knowledge you have gained, write a 
 brief description of the pupal stage of an insect and tell of what use 
 this stage might be to the insect. Remember where you find these 
 stages. 
 
 d. Adult or Imago 
 
 Method: Examine carefully an adult butterfly or moth. 
 
 Observations: How many body regions has it? How many legs? 
 Wings ? Antennae ? How does this stage differ from the pupal stage ? 
 Note : All the changes undergone by an animal from the time it 
 leaves the egg to the time it becomes an adult are known as the 
 metamorphosis of that animal. If no great changes in form occur, 
 the animal is said to have an incomplete or direct metamorphosis. 
 But if changes in form such as in the butterfly or moth occur, the 
 animal is said to pass through a complete or indirect metamorphosis. 
 
 Conclusion: i. What insects that you have studied pass through a direct 
 metamorphosis? An indirect' metamorphosis? 2. If time permits, 
 drawings might be made to illustrate the life history (metamorphosis) 
 of a moth or a butterfly. 
 
LIFE HISTORY OF INSECTS 
 
 321 
 
 Life history of insects. If we should watch the life 
 of an animal from the egg to the time it develops into an 
 adult and dies we would see its life history. There is a 
 great similarity in the life history of those insects which pass 
 through a com- 
 plete metamor- 
 phosis. They 
 have four stages. 
 The egg is the 
 first stage, often 
 laid on a plant 
 upon which the 
 young insect will 
 feed. This stage 
 is followed by 
 one known as 
 the larval stage, 
 during which the 
 animal feeds and 
 grows rapidly. 
 Familiar exam- 
 ples of the larvae 
 are the caterpil- 
 
 i u 
 
 lars Or WOrmS 
 
 we see eating 
 our garden vegetables, or the maggots we see in decay- 
 ing meat. After the larva has eaten and grown larger, 
 shedding its skin several times, it settles down, and if a 
 moth, spins a cocoon, and becomes quiet for a period. 
 This is known as the pupal stage. Finally the adult in- 
 sect breaks out from the pupa, and lives a relatively 
 short life, cluring which its eggs are laid, and the life his- 
 
 H.-WHIT. CIV. SCI. IN THE HOME 21 
 
 Monarch butterfly: adults, larva, and pupa on their food 
 plant, the milkweed. (From a photograph loaned by the 
 American Museum of Natural History.) 
 
322 PLANT FRIENDS AND PLANT PESTS 
 
 tory or cycle begins over again. Much harm is done in 
 our gardens by insects in the larval stage, as, for exam- 
 ple, caterpillars, cutworms, wireworms, and the like. A 
 great many insects, in the adult stage, however, do dam- 
 age by sucking juices from plants. These are bugs, and 
 are known by their long sucking beaks. The seventeen- 
 year locust or common cicada, and the squash bug, are 
 good examples. Still other adult insects such as the 
 locusts, commonly called grasshoppers, do much harm by 
 chewing grass or vegetables which make up their food. 
 
 Collecting insects. A very interesting and profitable 
 pastime is the collection and identification of different 
 kinds of insects. It is very easy to get an equipment 
 necessary to collect them. A few cigar boxes, pieces of 
 flat cork, insect pins, a cyanide bottle, 1 and a collecting 
 net are all of the implements necessary. Insects are di- 
 vided by scientists into orders, or groups, which have cer- 
 tain characteristics in common. There are nineteen orders, 
 but only five or six are very common, and these are 
 quite easily learned. Study any good elementary biology, 
 and you will soon be able to distinguish the chief orders. 
 For our purposes it is enough for us to know the insects 
 which do harm in our gardens by chewing, and the insects 
 which do harm by sucking. 
 
 Experiment. To learn to recognize insects that frequent flowering or 
 
 garden plants. 
 Method: This work may best be taken on a field trip. 
 
 Note : Insects have been shown to be animals that have three 
 
 1 A cyanide bottle is made by taking a wide-mouth bottle or a fruit 
 jar, placing in it a small piece of cyanide of potassium, and covering this 
 quickly with soft plaster of Paris. The cyanide is deadly poison. The 
 fumes are sufficient to make you sick, so a cyanide bottle is best prepared 
 by some older person, and should be handled with great care. 
 
COLLECTING INSECTS 323 
 
 parts to the body, three pairs of jointed legs, feelers, compound eyes, 
 and a more or less hard skeleton on the outside of the body. They 
 may or may not have wings. They breathe through a system of air 
 tubes called tracheae. 
 
 The following orders or groups of insects are likely to be found feeding or 
 living upon flowering plants. The position arid kind of wings and the 
 kind of mouth parts are the guides by which we know the orders of insects. 
 
 Bees and Wasps (Hymenoptera, membrane wings). The wings are 
 gauzy and four in number. These insects have stings (look at the end 
 of the abdomen). 
 
 Butterflies and Moths (Lepidoptera, scale wings). Characterized 
 by having two pairs of large wings, covered with tiny bright-colored 
 scales. Head provided with a long proboscis or sucking tube which is 
 coiled up when at rest. 
 
 Grasshoppers (Orthoptera, straight wings). Found on most green weeds 
 or garden plants. The mouth parts are fitted for biting. Hind wings, 
 if present, are folded up lengthwise under the outer wings when at rest. 
 
 Flies (Diptera, two wings). Usually small insects with but a single pair 
 of gauzy wings. A short proboscis. Not plant feeders. 
 
 Bugs (Hemiptera, half wings). A jointed proboscis which points 
 backwards is the only sure mark of this group. 
 
 Beetles (Coleoptera, sheath wings). Characterized by having a strong 
 front pair of wings called elytra, usually covering the hind wings and 
 always meeting in a straight line down the middle of the back. Mouth 
 parts hard, pincher-like jaws. 
 
 a. Field Work 
 
 Method: Collect as many different kinds of insects as you can, making 
 careful notes as to the locality where the insect was found, the flowers 
 which it frequents, the kind of food it was taking from the flower, and 
 the order to which it belongs. 
 
 b. Laboratory Work 
 
 Observations: From boxes containing different kinds of insects pick out 
 one from each order given above and give your reasons for placing 
 that particular insect in the order which you have chosen for it. 
 
 Conclusion: i. Why do certain insects always frequent certain flowers? 
 Look at the insect, especially the mouth parts, very carefully and 
 study the form of the flower before making your decision. 2. How 
 would you pick out (a) bee, (b) butterfly, (c) a bug, (d) grasshopper 
 from the above insects? 
 
324 PLANT FRIENDS AND PLANT PESTS 
 
 c f 
 
 a, Bee ; 6, butterfly ; c, grasshopper ; d, fly ; e, bug ; /, beetle. 
 
SOME INSECT PESTS AND HOW TO FIGHT THEM 325 
 
 Some insect pests and how to fight them. We must 
 expect certain insect pests in our gardens, and because 
 they prefer certain foods, only one or two kinds of insects 
 will attack each plant. These paragraphs are not in- 
 tended to give you more than a hint as to the insects and 
 what to do to destroy them. You will be interested to 
 make a home project of the disposal of the pests, and refer 
 to the lists of bulletins and books given at the end of this 
 chapter. You should always remember that where poisons 
 are used, they are poisons to younger brothers and sisters, 
 as well as to insects. Keep all spraying solutions, and 
 also all other poisons, well out of the reach of children, and 
 exercise care and common sense in using them. The fol- 
 lowing list of garden vegetables with their pests, and 
 methods of fighting them, will be found useful. 
 
 VEGETABLE 
 
 INSECT 
 
 PREVENTION AND CURE 
 
 String beans 
 
 Cabbage 
 
 Cauliflower 
 Corn 
 
 Cucumber 
 Potato 
 
 Squasta 
 
 Aphids (plant lice) 
 
 Bean weevil \ 
 Bean beetle / 
 
 Plant lice 
 
 Cabbage worm 
 
 Cabbage borer 
 
 Cabbage worm 
 
 Army worm (trav- 
 els in large num- 
 bers) 
 
 Corn root worm 
 Drill worm 
 Cutworm 
 
 European corn 
 
 borer 
 
 Cucumber beetle 
 Potato beetle (bug) 
 
 Slugs 
 Squash borer 
 
 Since these spread from weeds to beans, keep the 
 weeds and other plants near the garden cut. 
 Spray with kerosene emulsion or tobacco 
 water. 
 
 Use same spray as above. 
 
 Soap emulsion or tobacco water. 
 Use Paris green and pick off the worms. 
 Use same methods. 
 
 Use Paris green and pick off the worms. 
 Dust with Paris green, or if numerous, kill by 
 means of kerosene. 
 
 Corn dies. Practice crop rotation. 
 
 Crop rotation. 
 
 Cutworms attack the silk and eat the end of 
 
 cob. Spray with arsenate of lead. 
 Report to state authorities; they will tell you 
 
 what to do. 
 
 Dust with ashes and use Paris green. 
 Watch plants and pick off eggs or young beetles 
 
 early. Spray with lime-Paris green . 
 Spray with Paris green or arsenate of lead. 
 
 Burn vines, practice crop rotation. 
 Kill young with kerosene. 
 
326 
 
 PLANT FRIENDS AND PLANT PESTS 
 
 Experiment. To illustrate the proper way of making some insecticides and 
 fungicides; lime-sulphur, arsenate of lead, Bordeaux mixture, and 
 kerosene emulsion. 
 
 Prepare several of these, using the quantities suggested in column 
 " For Experiment " in table below. This table shows what to use 
 and how to prepare the most commonly used garden sprays : 
 
 
 GARDEN 
 
 AND 
 
 ORCHARD 
 USE 
 
 FOR 
 
 EXPERIMENT 
 
 DIRECTIONS FOR MAKING 
 
 LIME-SULPHUR 
 
 
 
 Nearly cover the lime with water. When 
 
 FUNGICIDE 
 
 
 
 it is slaking add the sifted sulphur. 
 
 For Delicate Foliage 
 Quicklime . . . 
 Sulphur .... 
 Water . . . 
 
 2lb. 
 2lb. 
 
 12 gal. 
 
 2 gm. 
 2 gm. 
 
 IOO CC. 
 
 Stir constantly and add a little water 
 if it gets very dry. After five min- 
 utes add water to make specified 
 quantity. 
 
 LIME-SULPHUR SPRAY 
 
 
 
 Mix lime and sulphur and \ the quantity 
 
 For Sucking Insects 
 Quicklime ... 
 Sulphur .... 
 Water . 
 
 4 lb. 
 3lb 
 10 gal. 
 
 3gm. 
 85 cc. 
 
 of hot water. Boil one to two hours, 
 or until it has a dark amber color. 
 Dilute to indicated quantity and 
 apply warm. 
 
 ARSENATE OF LEAD 
 
 
 
 Mix the arsenate of lead thoroughly in 
 
 Spray for Chewing 
 
 
 
 the water. 
 
 Insects 
 
 
 
 
 Arsenate of lead 
 
 
 
 
 paste (use | the 
 
 
 
 
 quantity if pow- 
 
 
 
 
 dered is used) 
 
 i ib. 
 
 \ gm. 
 
 
 Water 
 
 12 gal. 
 
 IOO CC. 
 
 
 BORDEAUX MIXTURE 
 
 
 
 Dissolve the sulphate in a large wooden 
 
 Fungicide and 
 Germicide 
 
 
 
 vessel, or in a glass if a small quan- 
 tity. Slake the lime to make a 
 
 Copper sulphate . 
 Quicklime . . . 
 Water 
 
 ilb. 
 ilb. 
 12 gal. 
 
 i gm. 
 i gm. 
 
 IOO CC. 
 
 creamy mixture, then add water to 
 make thin. Strain the milk of lime 
 through cheesecloth into the solution 
 of copper sulphate. 
 
 LIME-PARIS GREEN 
 
 
 
 Mix the Paris green and water and add 
 
 Spray to Control 
 Potato Beetle 
 
 
 
 filtered milk of lime. 
 
 Paris Green . . . 
 
 2 OZ. 
 
 i orn 
 
 
 Lime 
 
 ilb. 
 
 1 gm. 
 
 
 Water 
 
 12 gal. 
 
 IOO CC. 
 
 
 KEROSENE EMUL- 
 SION 
 
 
 
 Dissolve the soap in about $ of the 
 water, which must be boiling hot. 
 
 Spray for Plant Lice 
 Hard soap . . . 
 Kerosene .... 
 
 lib 
 i gal. 
 
 igm. 
 
 10 CC. 
 
 Warm the kerosene and add. Stir 
 vigorously until creamy. Add the 
 remainder of the water. 
 
 Water (soft) . . . 
 
 12 gal. 
 
 IOO CC. 
 
 
INSECT FRIENDS 327 
 
 Insects harmful to fruit trees. The codling moth ruins 
 $3,000,000 worth of fruit each year in New York state alone. 
 Most of us know this pest as the " worm " in the apple. 
 Spraying the trees when the petals begin to fall is the 
 best method of destroying this pest. In some localities 
 there is more than one brood of codling moths in sum- 
 mer, in which case the spraying has to be repeated for 
 the other broods. The canker worms, tent caterpillars, 
 plum curculio, and scale insects also attack fruit trees. 
 Borers sometimes do much injury to fruit trees, and are 
 very hard to fight as they work into the tree trunk near 
 the ground. Digging them out and filling holes with car- 
 bon bisulphide are the best ways to fight them. 
 
 Other plant enemies. Those of us who have lived on 
 the farm know some other garden pests. The ordinary 
 cottontail or the common gray rabbits often do much 
 damage by eating garden vegetables and fruits, and es- 
 pecially by gnawing young fruit trees. They live in 
 burrows which they dig under cover of weeds and thick 
 grass. They breed rapidly, sometimes having several 
 litters of from two to four each, in a single season. Rats 
 from the barn, and more frequently field mice, do a great 
 deal of damage to our gardens and trees. The ground 
 mole, although in some ways useful because of its diet 
 of insect larvae and grubs, digs up our lawns and gardens 
 so as to become a pest about the place. 
 
 Insect friends. Everybody knows that bees are useful 
 for they not only make honey but they also do a far 
 greater good by carrying pollen from flower to flower, thus 
 aiding in the growth of seed and fruits. We shall discuss 
 the life habits of bees more fully in our next book. The 
 ichneumon flies, near relatives of the bees, are of much 
 
328 
 
 PLANT. FRIENDS AND PLANT PESTS 
 
 Two valuable garden friends. 
 
 value to man because they lay eggs on the bodies of cater- 
 pillars harmful to vegetation. As these eggs develop the 
 
 young ichneumons 
 live on the body of 
 the caterpillar and 
 eventually kill it. 
 Some beetles are 
 of use as garden 
 friends, especially 
 the " lady bug " or 
 lady bird beetle, 
 
 which feeds upon plant lice or aphids. Some insects feed 
 
 upon weeds and they too can be classed as our friends. 
 Other garden friends. 
 
 Insects and some animals, 
 
 such as field mice, are kept 
 
 under control by birds. Our 
 
 neighbor the robin, whom 
 
 we sometimes begrudge a 
 
 few cherries, is of more use 
 
 than harm because of his 
 
 insect diet. Our earliest 
 
 visitor, the bluebird, lives 
 
 largely on injurious insects, 
 
 as do the woodpeckers, 
 
 cuckoos, kingbirds, and 
 
 many others. Many birds 
 
 live upon insects which are 
 
 most numerous around them. 
 
 When great numbers of in- 
 sects are present, birds do an Food of some common birds. Which of 
 
 the above birds should be protected by 
 
 immense amount Of gOOd. man and why ? 
 
 AMERICAN CROW 
 
 ENGLISH SPARROW 
 
OTHER FRIENDS OF THE GARDEN 
 
 329 
 
 Birds eat weed seeds. Birds also help us in our gar- 
 dens by eating weed seeds ; especially beneficial are our 
 native sparrows (not the English sparrow), the bobwhite, 
 the mourning dove, and others. Those birds which stay 
 with us late in the fall often devour great numbers of weed 
 seeds, which are thus prevented from sprouting and grow- 
 ing the following year. Sometimes birds, such as owls, 
 eat rats, field mice, and other pests. We should all band 
 together to prevent the destruction of our native birds, 
 
 and to encourage 
 
 nesting in the 
 trees and shrubs 
 around us. House 
 cats, and more 
 often stray cats, 
 are of great harm, 
 because they 
 either kill or 
 frighten away the 
 birds and prevent 
 them from nest- 
 ing in the neigh- 
 borhood. 
 
 Other friends of the garden. We do not think of a 
 toad as being a beautiful animal, but every boy and girl 
 who keeps a garden should have a friendly toad living under 
 one of the big-leaved plants in it. Toads have been found 
 to eat no less than eighty-three different kinds of insects, 
 most of which are injurious. A single toad has been esti- 
 mated by Kirkland, on account of the cutworms which 
 it might kill, to be worth nearly twenty dollars a season, 
 if the damage done by each cutworm were estimated at 
 
 The common toad, an insect eater. 
 
330 PLANT FRIENDS AND PLANT PESTS 
 
 only one cent. Snakes, most of which are harmless, are 
 also garden friends. The black snake and milk snake 
 feed largely on rats and mice, while the common green 
 snake eats injurious insects, and the little brown De Kay 
 and garter snakes have a diet including slugs, which 
 sometimes do much damage in the garden. 
 
 REFERENCE BOOKS 
 
 Forbush, Useful Birds and Their Protection. Massachusetts Board of Agriculture. 
 
 Hodge, Civic Biology, Chapters IV, XII, XIV. Ginn and Company. 
 
 Hodge, Nature Study and Life, Chapter XVI. Ginn and Company. 
 
 Hunter, A Civic Biology, Chapter XV. American Book Company. 
 
 Hunter, Laboratory Problems in Civic Biology, Chapter II. American Book Com- 
 pany. 
 
 Kellogg and Doane, Economic Zoology and Entomology, Part II, Chapters XXX, 
 XXXII, XXXIII, XXXIV, XXXV, XXXVI. Henry Holt and Company. 
 
 Mayne and Hatch, High School Agriculture, Chapters V, VI. American Book 
 Company. 
 
 Merriman, Birds of Village and Field. Houghton Mifflin Company. 
 
 Moore and Halligan, Plant Productions, Part II, Chapter VII. American Book 
 Company. 
 
 Sanford, The Story of Agriculture in the United States. Dl C. Heath and Company. 
 
 Spillman, Farm Science, Chapters XII, XIII, XIV. World Book Company. 
 
 Trafton, Science of Home and Community. The Macmillan Company. 
 
 Webster, Value of Insect Parasitism to the American Farmer. U. S. Dept. of Agri- 
 culture Yearbook, 1907. 
 
 Weed, Farm Friends and Farm Foes. D. C. Heath and Company. 
 
 U. S. Dept. Agriculture, Farmers' Bulletins. (There are very many of these, each 
 treating a definite insect pest, or dealing with a definite fungus.) Ask to be 
 placed on the mailing list for the monthly list of bulletins. Then you may 
 select and send for those which interest you. 
 
PART VI. DEVICES FOR LABOR 
 SAVING AND CONVENIENCE 
 
 CHAPTER XXI 
 
 SOME SIMPLE MACHINES IN THE HOME 
 
 Problems. i. To understand the principles underly- 
 ing simple machines used in and about the house. 
 2. To understand what advantages machines offer. 
 
 Experiments and demonstrations. i . To demonstrate the principle of 
 levers. 
 
 2. To illustrate changing speed by use of wheels of different diameters, 
 joined by belt or gears. 
 
 Project 1. To KEEP THE MACHINES OF THE HOME IN GOOD WORK- 
 ING CONDITION. 
 
 1. Learn how to operate all the different household machines. 
 Learn what oiling is necessary, and how to keep free from dust 
 
 and dirt. 
 
 2. What other attention is needed from time to time? 
 
 3. Study the mechanism of the more complicated machines to 
 know how the machines work. 
 
 4. If needed repairs are too difficult for you to do, be ready to 
 advise where repairs should be made. 
 
 Suggested Projects. 
 
 I. TO DETERMINE THE TYPES OF MACHINES AND THE MECHANICAL 
 ADVANTAGE OF TEN DIFFERENT MACHINES FOUND IN MY HOME. 
 
 331 
 
332 SOME SIMPLE MACHINES IN THE HOME 
 
 2. TO STUDY THE DIFFERENT TYPES OF WASHING MACHINES AND 
 
 DECIDE WHICH IS BEST SUITED TO HOME USES. 
 
 3. PROCURE HOUSEHOLD SCALES. HAVE THEM ADJUSTED BY 
 DEPARTMENT OF WEIGHTS AND MEASURES. WEIGH GROCERIES, 
 
 MEATS, ETC., BOUGHT, AND SEE IF CORRECT WEIGHTS ARE DELIVERED. 
 
 4. TO DETERMINE HOW A LAWN MOWER WORKS, WHAT TYPES OF 
 SIMPLE MACHINES ARE IN IT, AND APPROXIMATELY THE RELATION 
 OF POWER TO WORK. 
 
 5. TO DETERMINE WHAT MACHINE PRINCIPLES ARE USED AND 
 HOW THEY ARE APPLIED IN THE DOOR KNOB, LATCH, AND LOCK. 
 
 Thought Questions. 
 
 1. May the hands of a clock be considered as machines of the 
 lever type? 
 
 What class of lever are they, and what advantages as machines 
 have they? 
 
 2. Explain the type of simple machine you use when you wind a 
 watch or a clock. 
 
 Why we use machines in our homes. If we had 
 
 lived a great many years ago, we would have found 
 that there were very few devices which enabled our an- 
 cestors to save labor in their homes. Much work was 
 done by hand, and a few simple machines, such as churns, 
 spinning wheels, wagons, and the like, were used to do 
 most of the mechanical work. In the present era, an 
 age of machinery, we have come to save time and also save 
 our own energy by using machines to help us do the work. 
 We find also that machines are usually much more effi- 
 cient than we are, and so it is that we have year by year an 
 increasing number of devices for labor saving in our homes. 
 Each year some new device is perfected, and it is a wise 
 housekeeper who can select from such a multitude of ma- 
 chines now offered in the market those which are mechani- 
 cally perfect, and serviceable and durable. It is the pur- 
 
TWO TYPES OF MACHINES USED IN THE HOME 333 
 
 pose of this chapter to point out a few of these machines, 
 and to try to explain the simple principles which underlie 
 their construction and regulation. 
 
 Two types of machines used in the home. The lever 
 and the wheel and axle are two types of simple machines 
 which play an important part in the construction of many 
 household devices. 
 If we look at a pair 
 of shears, for ex- 
 ample, we find them 
 to be made of. two 
 pieces of metal, held 
 together at one point 
 by a rivet with the 
 inner edges sharp- 
 ened at an angle. 
 If we try to cut a 
 piece of thick cloth 
 with these shears, 
 we find it much 
 more difficult to cut 
 the cloth when it 
 is placed farther 
 away from the point 
 where the parts of 
 the shears are ro- 
 tating, while it cuts 
 much easier close to the point of rotation. The shears 
 illustrate the lever, the force we exert being called the 
 force, the resistance we overcome in the cutting of the 
 cloth the weight, since it is measured in units of weight, 
 and the point at which the shears revolve, or turn, is called 
 
 In which of each of these three cases will the same re- 
 sistance be overcome by a smaller force ? P=force. 
 W=weight (resistance). F=fulcrum. 
 
334 SOME SIMPLE MACHINES IN THE HOME 
 
 the fulcrum. Another example of such an instrument is 
 seen in the sugar tongs, where we find it is much easier 
 to hold the lump by placing the fingers close to the 
 lump than it is if we were to apply the force far away 
 from it. 
 
 The wheelbarrow is a lever. Almost any boy or girl 
 who lives in the country knows that it is easier to carry 
 a heavy load on the wheelbarrow if the load is placed 
 nearer to the wheel than to the handles (see diagram). 
 The nearer the load can be placed to the wheel, the 
 greater the ease with which the load can be lifted and 
 carried. All of these machines mentioned use a common 
 principle, that of the lever. Let us now study and 
 experiment more closely, and see if we can understand 
 the principles underlying it. 
 
 Experiment. To demonstrate the principle of the lever. 
 
 Materials: Ruler with hole in the center. Weights and string. 
 
 Method: With the lever illustrated find out where a force of i pound 
 must be applied on the force arm to balance the different weights sug- 
 gested in (a), (6), and (c), 
 applied on the weight arm. 
 (a) Place 2 pounds 2 
 inches from the fulcrum. 
 (6) Place 2 pounds 4 
 inches from the fulcrum. 
 (c) Place 6 pounds i 
 inch from the fulcrum. 
 Observation and conclusion: 
 Where will a force of i 
 pound need to be applied 
 to balance the weight in 
 each of the cases (o), (6), 
 From the result of the experiment tell what is wrong an( j ( c ) p c an you work 
 
 out the principle of levers 
 
 by comparing the forces and lengths of arms in each case? What 
 statement will you suggest for the law of levers ? 
 
 F. A . - *-WA. 
 
 4 iV T " " 
 
 (weight) 
 
MECHANICAL ADVANTAGE 
 
 335 
 
 Three classes of levers. There are three classes of 
 levers which depend on the position of the fulcrum, the 
 weight, and the force. The relative positions of these 
 are as follows : In levers of the first class, the fulcrum 
 comes between the weight and the force ; in levers of the 
 second class, the weight comes between the fulcrum and 
 the force ; in levers of the third class, the force comes 
 
 Levers of the Tinst Class 
 
 /uJc'runv. 
 y ; 
 
 /orce 
 
 CD. 
 
 weight 
 
 levers y the Second Clcrss 
 
 /ulcru 
 
 >reigrKt /orce 
 
 r w 
 
 r w 
 
 levers of the Third Class 
 
 Common examples of the three classes of levers. 
 
 between the weight and the fulcrum. The shears belong 
 to the first class of levers, the wheelbarrow to the second 
 class, and the sugar tongs to the third class. 
 
 Mechanical advantage. We use ordinarily a machine 
 to overcome a force greater than that which we apply. If 
 by means of a machine we can lift 200 pounds by applying 
 a force of 25 pounds, then the mechanical advantage of 
 the machine is 8 ; it is equivalent to the force moved di- 
 vided by the force applied. With levers of the third class 
 
336 
 
 SOME SIMPLE MACHINES IN THE HOME 
 
 we must apply more force than the resistance to be over- 
 come. Then why use such a machine? There is another 
 advantage for which some machines are used, that is, speed 
 and distance moved. The advantage of levers of the 
 third class is that of speed or distance covered. Notice 
 how this is shown in the sugar tongs. 
 
 How we weigh things. A pair of scales at home is a 
 necessary thing, for it may save more than its cost many 
 times over in checking up the weight of groceries and other 
 materials. Most scales in use are dependent on the prin- 
 ciple of the lever. 
 In the scales in the 
 picture, can you tell 
 whether you would 
 get more or fewer 
 apples if the sliding 
 weight were placed 
 at point A or at 
 point B ? Can you 
 explain why ? An- 
 other household scale not dependent on the principle of the 
 lever is the spring balance. To explain such a scale, let 
 us suspend a coiled wire with a pointer fastened at the 
 bottom. Let us now fasten to the wire, weights weighing 
 10, 20, and 30 grams respectively. As the weights pull 
 the wire down, mark the position of the pointer on the 
 scale representing 10, 20, and 30 grams. We might con- 
 tinue this scale to make several more marks, and as long 
 as the elasticity remained in the wire, we could then use 
 this for weighing purposes. This is the principle of the 
 spring balance or postal balance used for weighing letters. 
 The lawn mower. If you have pushed a lawn mower 
 
 Principle of the lever used in weighing. 
 
K.U IN i\ .&.:> 
 
 661 
 
 along a level lawn, you must have noticed that the force 
 you applied is distributed in two directions. You push 
 the lawn mower forward, but you also push it downward. 
 This downward motion is applied in increasing the pres- 
 sure of the wheels against the ground, thus causing them 
 to turn around without sliding. The horizontal force 
 is used in moving the wheel forward, and also in turning 
 the wheel. If you turn a lawn mower upside down so that 
 the revolving knives do not hit the grass, you will notice 
 that it runs more easily. A large part of your energy, 
 then, goes in moving these knives, which are retarded by 
 pressure against the grass and 
 the lower part of the lawn 
 mower. If two boys work to- 
 gether in cutting a lawn, the 
 work can be made much lighter 
 by one boy fastening a long rope 
 in front of the mower and pull- 
 ing. Can you explain why? 
 
 Wheels and runners. Why 
 do our wagons have wheels and 
 our sleds runners? Perhaps you know that when we 
 move one body over another, a certain amount of re- 
 sistance known as friction must be overcome. Have you 
 ever pulled with all your might to drag a heavily loaded 
 box over the floor and then placed one or more rollers, 
 such as can be made from a broom handle, under the box 
 and found how easily it could be pulled? In much the 
 same way a load on a wagon is moved over the bare road 
 more easily than the same load on a sled. The sled runner 
 slides over the road surface, while the wagon wheel rolls 
 over it; and sliding friction is greater than rolling friction, 
 
 H.-WHIT. CIV. SCI. IN THE HOME 22 
 
 The push () is divided into two 
 parts: force A downward, which 
 gives the necessary friction for the 
 wheels to turn, and force C, which 
 rotates the blades and moves the 
 mower forward. 
 
338 SOME SIMPLE MACHINES IN THE HOME 
 
 But why not use wheels on ice and snow? If you ever 
 tried your roller skates on ice you know the difficulty 
 of getting started. This is because of the lack of sufficient 
 friction. Such smooth surfaces as glass, ice, and well- 
 worn snow have very little resistance to the movement of 
 hard objects over their surfaces. Sled runners have 
 
 many more points 
 of contact with a 
 supporting surface 
 than have wheels ; 
 but because of the 
 very low friction 
 
 Ball bearings. 
 
 between ice and 
 
 smooth steel, steel runners are better for snow and ice 
 than wheels. With skates there are fewer points of con- 
 tact and the friction is sometimes reduced still more for 
 another reason. When skating in moderate weather, the 
 pressure, due to your weight, melts the ice under the run- 
 ners and you really glide over water. This water freezes 
 instantly after the skates have left it. 
 
 The law of machines. Machines do not make energy. 
 They simply transfer or exchange force or mechanical 
 energy from one place to another. We shall see as we go 
 on in our study of science that energy is simply the ability 
 to do work. Sometimes this energy is locked up, as in coal, 
 which gives heat when burned, or it may be evident as in 
 the power in the running stream, or in the waves, or in the 
 wind. By use of a machine we may transfer this energy 
 or power from one place to another, and by means of a 
 machine get work done more effectively. The chief value 
 of machines lies in their enabling us to overcome a large 
 resistant force by applying a small force. But we must 
 
THE APPLICATION TO SOME OTHER MACHINES 339 
 
 remember that we can get no more work out of a machine 
 than we put into it. The law of machines may be stated 
 as follows : The force applied to a machine times the distance 
 through which it acts equals the resistance overcome times 
 the distance through which it is overcome. That is, if you 
 move a 2oo-pound weight i foot by applying a force of 20 
 pounds, this force would have to act through a space of 
 10 feet. 200X1 = 20X10. 
 
 Unit of work. The term we use for the unit of work 
 is the foot pound. This is exactly what its name indicates. 
 If we lift a pound one foot, the result is a foot "pound, or 
 if we lift four pounds four feet from the ground, we do 
 sixteen foot pounds of work. In other words, the work 
 equals the weight multiplied by the distance. 
 
 The application to some other machines. If we now 
 apply this rule to such other machines as the meat chop- 
 per, clothes wringer, coffee 
 grinder, and ice cream 
 freezer; we find that we can 
 easily estimate the amount 
 of force which must be ex- 
 erted to make them do their 
 work. In the machines just 
 mentioned, we apply force 
 by the hand with a crank or 
 handle which is revolved 
 through a circular path. All 
 of the machines belonging 
 to this type are known as 
 the crank and axle, or the wheel and axle type. The work 
 is done at a point on the circumference of the axle. If 
 the circumference of the roller of the clothes wringer is 
 
 The clothes wringer; a crank and axle 
 machine. 
 
340 SOME SIMPLE MACHINES IN THE HOME 
 
 six inches, and the circumference of the circle described by 
 the hand in operating the handle is sixty inches, then the 
 resistance of 200 pounds at the roller would require you to 
 expend only twenty pounds at the wringer handle. Ex- 
 press this in terms of the law of machines. 
 
 Wheels of different diameters connected by belts or 
 interlocked by gear teeth are used for the purpose of 
 changing speed as well as for the reason of mechanical 
 advantage. A study of a few home machines will make 
 this apparent and explain the purpose of their use. 
 
 Experiment. To illustrate changing speed by use of wheels of different 
 diameters joined by belt or gears. 
 
 Materials: A Dover egg beater, or drill with gear and wheels. Bicycle. 
 
 Method: (A) Mark one point on the working part of the egg beater. 
 Observe how many times this revolves for one complete turn of the 
 handle. Try this three times. (B) Count the number of cogs on the 
 two wheels which connect the force end of the machine to the work end. 
 What is the relation of the numbers of cogs? (C) Make similar com- 
 parison of the cogs on the rear axle and on the sprocket wheel of your 
 bicycle. Find the number of revolutions of the rear wheel to one 
 revolution of the crank. What general rule regarding change of speed 
 is suggested to you by these observations? 
 
 The sewing machine. A great many other types of 
 machines can be found in our homes, but one almost al- 
 ways present is the sewing machine. Since 1850 these 
 machines have been improved more and more, so that 
 now their work is extremely rapid and efficient. A study 
 of the part that does the stitching is somewhat too com- 
 plex for us at the present time, but would make a very 
 interesting home project' which could be studied by means 
 of diagrams furnished by almost any good machine supply 
 house. One good project which could be worked out in 
 the laboratory would be to find out how power is trans- 
 
OTHER MACHINES 
 
 341 
 
 mitted in the sewing machine. Notice we have a treadle 
 which transfers power to the drive wheel. If we measure 
 the diameter of this wheel, and the diameter of the pulley 
 over which the belt passes, we can easily determine 
 how many revolutions of the pulley will be pro- 
 duced by one revolution of the drive wheel, then 
 by carefully turning the pulley one complete revo- 
 lution, we can find how many stitches the machine 
 takes in each complete revolution. This is only 
 one of the problems which can be 
 worked out in connection with a 
 sewing machine. 
 
 Other machines. A number 
 of other mechanical principles are 
 found in many machines used in 
 the home. Among them are the inclined plane, the wedge, 
 the screw, and the pulley. We have all used the inclined 
 plane in rolling heavy objects like the barrel up a grade. And 
 we have used the wedge, which is really two inclined planes 
 
 B 
 
 Observe how the screw is in reality 
 a spirally inclined plane. Ex- 
 plain diagram. 
 
 Illustrating the use of the screw. 
 
 put side by side, points together, in the ax or hatchet. The 
 common wedge when driven into the wood, forces it apart. 
 The screw is nothing more or less than a long inclined 
 
342 SOME SIMPLE MACHINES IN THE HOME 
 
 plane placed in the form of a spiral. We have seen the 
 use of the jack screw under automobiles in case of tire 
 trouble. Again it is simply the use of force or energy 
 exerted on an inclined plane which runs round and round 
 the jack. Pulleys are not used so often 
 in the home although a familiar example 
 is seen in the supports of the painter's 
 staging. A glance at the diagram will show 
 how they are used. 
 
 The small vacuum washer. Many homes 
 nowadays have washing machines. A small 
 hand washer using the vacuum principle does 
 good work. The cone-shaped metal washer is 
 fastened to a handle and the large end is 
 open. There are holes in the sides of this 
 cone. If this washer is pushed down and 
 lifted up alternately with a great deal of vigor, 
 air will be forced out on the down stroke, and 
 the vacuum produced on the up stroke sucks 
 the water up through the clothes under the 
 washer. The use of such an instrument as 
 this is very effective in washing blankets and 
 delicate materials which may be injured by rubbing. 
 What is the explanation of suction ? 
 
 Washing machines. Washing machines are of two 
 kinds as far as the inside working is considered. In one 
 the system of vacuum domes is similar to the one just de- 
 scribed and is operated mechanically inside of the closed 
 tub. In the second type the clothes are held in a perforated 
 drum which revolves first in one direction and then in the 
 other. This drum sets in water held in the outside con- 
 tainer. The constant whirling of the water back and forth 
 
 With this pulley 
 a weight of 600 
 pounds can be 
 supported by 
 a force of 100 
 pounds. 
 
REFERENCE BOOKS 343 
 
 and through the clothes washes them. This machine may 
 be operated in a number of different ways, by hand 
 lever, crank, water motor, or electric motor. The hand- 
 operated machines are very efficient, but require time and 
 attention. The motor-driven ones are much more expen- 
 sive, but save work. 
 
 REFERENCE BOOKS 
 
 Bachman, Great Inventions and Their Inventors (Sewing machine). American Book 
 
 Company. 
 
 Barber, General Science, Chapter X. Henry Holt and Company. 
 Black and Davis, Practical Physics, Chapter II. The Macmillan Company. 
 Brownell, General Science, Chapter VII. P. Blakiston's Son and Company. 
 Caldwell and Eikenberry, General Science, Part III, Chapters XV, XVI. Ginn and 
 
 Company. 
 Central Scientific Company, Chicago, Catalogue with illustrations of simple machines 
 
 for projects. 
 Child, The Efficient Kitchen (For teachers), Chapters II, XIV. McBride, Nast 
 
 and Company. 
 
 Clark, An Introduction to Science, Chapter XXXII. American Book Company. 
 Clark, The Care of a House (For teachers). The Macmillan Company. 
 Carhart and Chute, Physics with Applications, Chapter VI. Allyn and Bacon. 
 Fall, Science for Beginners, Chapter XXXIII. World Book Company. 
 Hessler, The First Year of Science, Chapter X. Benj. H. Sanborn Company. 
 Hoadley, Essentials of Physics, Chapter III. American Book Company. 
 Hodgdon, Elementary General Science, Chapter XIV. Hinds, Hayden and Eldredge. 
 Knott Apparatus Company, Boston. Catalogues with illustrations of simple 
 
 machines for projects. 
 
 Lynde, Physics of the Household, Chapters I, II, III. The Macmillan Company. 
 Singer Sewing Machine Company, Mechanics of Sewing Machines. 
 Van Buskirk and Smith, The Science of Everyday Life, Project XV. Houghton 
 
 Mifflin Company. 
 
 . Van Rensselaer, Manual of Home Making (Teachers' use), Chapter III. The Mac- 
 millan Company. 
 Williams, How It Works. Nelson Company. 
 
CHAPTER XXII 
 
 HOW ELECTRICITY IS USED IN THE HOME 
 
 Problems. i. To learn the properties of magnets and 
 how magnetism is produced by electricity. 
 
 2. To find out what electromagnets are and what they 
 will do. 
 
 3. To understand the working of electric bells and how 
 to install them. 
 
 4. To find out how a simple motor works. 
 
 5. To see how electricity gives heat. 
 
 Experiments. i. To determine laws of magnetic poles. 
 
 2. To magnetize an iron bar in the field of another magnet and in the 
 earth's magnetic field. 
 
 3. To make an electromagnet. 
 
 4. To demonstrate the electric bell. 
 
 Project I. To INSTALL AN ELECTRIC BELL IN MY HOME. 
 
 1. Plan wiring, bell button, and battery location. 
 Concealed or outside wiring. Diagram. 
 
 2. Materials needed. 
 
 3. Make the installation. 
 
 Suggested Projects. 
 
 1. TO MAKE A COMPASS OR A DIPPING NEEDLE. 
 
 2. TO MAKE A PERMANENT PRINT OF A MAGNETIC FIELD. 
 
 3. TO MAKE A TOY ELECTRIC MOTOR. 
 
 344 
 
MAGNETS AND THEIR PROPERTIES 
 
 345 
 
 Electricity in the home. Your father and mother can 
 doubtless remember the first time they saw the trolley car 
 or the incandescent light ; it was only a few years ago that 
 the wireless was first used. So we see that the harnessing 
 of this great power, electricity, has been comparatively 
 recent, and that we are just at the beginning of an era of 
 electricity and electrical devices. Modern households, 
 if well equipped, may have many of these labor saving and 
 useful instruments. There are three general types of elec- 
 tric devices. Examples of them are the electric door- 
 bell, the motor which drives the machine, and the elec- 
 tric iron. The bell and the motor depend upon electro- 
 magnetic action to do their work, while the iron depends 
 upon the heating effect of the electric current. In order 
 to understand even a little about these devices, it is neces- 
 sary for us to know something of the properties of elec- 
 tricity, particularly in its relation to magnetism. Every 
 boy and girl has 
 played with a magnet 
 or some toy in which 
 a magnet was used 
 and yet may not know 
 just what a magnet 
 is. 
 
 Magnets and their 
 properties. A great The magnetic strength is greatest near the ends> 
 many years ago, iron ore was found in Magnesia, Asia Minor, 
 which had the property of attracting to it other pieces of 
 iron. This ore was called magnetite, and the name magnet 
 was thus derived from the name of the country in which it 
 was first found. We can make artificial magnets, either by 
 rubbing a piece of steel with a natural magnet, or by hold- 
 
346 HOW ELECTRICITY IS USED IN THE HOME 
 
 ing it near one. In early times artificial magnets were 
 always made in this way, but since we have come to generate 
 electricity and send it in a current through wires, we find 
 that we can make better magnets by its use. Of this 
 process we shall learn later. 
 
 Experiment. To determine laws of magnetic poles. 
 
 Materials: A bar magnet. A suspended magnet (may use needle of 
 
 compass). 
 
 Method and Results: Bring the north pole of the bar magnet near the south 
 pole of the compass needle. Result? Bring the south pole near the 
 
 north pole. Result? 
 Make similar tests 
 with the south pole 
 of the bar magnet. 
 Results? 
 
 Conclusion: Formulate 
 a law concerning the 
 attraction and the re- 
 pulsion of magnetic 
 poles. 
 
 The properties of 
 magnets. As we 
 have seen magnets 
 attract unmagnet- 
 ized iron and steel. 
 They will also at- 
 tract two other met- 
 als, nickel and co- 
 balt. The attractive 
 
 What law of magnetism is illustrated here ? f Qrce fe greatest near 
 
 the ends of the magnets. These points of greatest at- 
 tractions are called the poles of the magnet. Halfway 
 between the poles is the magnetic equator, a region of 
 practically no magnetic attraction. If a magnet is sus- 
 pended so that it swings freely in a horizontal plane, it 
 
THE MAGNETIC FIELD 
 
 347 
 
 takes a north and south direction, the pole pointing north 
 being called the north pole, and the pole pointing south, 
 the south pole. If we bring the north pole of one magnet 
 near the north end of a suspended magnet, the north pole 
 moves away. If we bring the south pole of a fixed magnet 
 to the north pole of a movable one, the south pole is drawn 
 toward the north. These curious facts are always noticed 
 when two magnets are brought together, and from this we 
 are able to state the law, which is as follows : Like mag- 
 netic poles always repel, and unlike magnetic poles always 
 attract, each other. 
 
 The magnetic field. It is not necessary to touch a small 
 piece of iron such as a tack in order to attract it. You 
 have often noticed tacks 
 or bits of iron jump 
 across the air space to a 
 strong magnet. A com- 
 pass needle will turn 
 when several feet away 
 from a strong magnet. 
 These facts indicate that 
 the influence of the mag- 
 net extends in all direc- 
 tions. This force de- 
 creases as the distance 
 increases. The space about a magnet in which magnetic 
 influence exists is called the magnetic field. It is because 
 the earth itself is a huge magnet and has surrounding it 
 a magnetic field, that the compass needle takes a definite 
 direction. Every magnetic field is filled with magnetic 
 lines of force which are imaginary lines denoting the direc- 
 tion of the magnetic force. 
 
 A magnetic field. Iron filings scattered over a 
 magnet arrange themselves in the lines 
 shown. 
 
348 HOW ELECTRICITY IS USED IN THE HOME 
 
 Experiment. To magnetize an iron bar in the field of another magnet and 
 in the earth's magnetic field. 
 
 Materials: A three-inch length of soft iron. A strong bar magnet. 
 A three-foot length of iron gas pipe or soft iron rod. Compass. Dip- 
 ping needle. Fine iron filings. Hammer. 
 
 Method: (A) Test the three-inch iron rod by dipping it in iron filings. 
 If it shows no magnetic effect, place one end of it very near to one 
 pole of the bar magnet. Tap it two or three times with the hammer. 
 Now test it in the iron filings to see if it has become a magnet. 
 (B) Test the iron gas pipe by holding first one end and then the other 
 near the north end of the compass needle. If both ends attract the north 
 pole of the needle it is not magnetized and is ready to use. If one end 
 attracts while the other repels, its magnetism must be removed. This 
 may be done by holding the pipe horizontally in an east and west 
 direction and striking it with the hammer. After a few trials you 
 will find that its magnetism has disappeared. The compass indi- 
 cates the north and south direction. Place the dipping needle so 
 it is free to swing in this plane. Hold the gas pipe in a position 
 parallel to the dipping needle and strike one or two blows on the end 
 with the hammer. Test to see if the pipe now is a magnet by hold- 
 ing first one end and then the other near the compass needle. 
 
 Results and Conclusion: What are the results in (^4) and (B)? What is 
 one way of magnetizing substances? Why does the dipping needle 
 take the direction that it does? Why point the gas pipe in that same 
 direction ? Why do tools standing in one place in the house sometimes 
 become magnets? 
 
 Magnetic property of an electric current. If a wire 
 connecting the two poles of a dry cell is brought down 
 over a compass in a north and south line, the needle will 
 move just as it would if we brought another magnet near 
 it. This is evidence that a magnetic field surrounds 
 the wire. If the wire is coiled by winding a close layer 
 on a lead pencil and a current sent through it the wire will 
 act like a magnet with two poles. This is shown by bring- 
 ing first one end of the coil and then the other end near 
 the north end of the compass needle, for one end will at- 
 tract and the other end will repel. The coil of wire behaves 
 
AN ELECTRIC BELL SYSTEM 349 
 
 like a magnet. If a bar of soft iron be slipped inside the 
 coil, it will act as before, but with far greater strength. 
 Such a device as this last, that is, a bar of soft iron having 
 a current of electricity passing through a wire surround- 
 ing it, is known as an electromagnet. The magnetic prop- 
 erty of an electromagnet ceases the instant the electric 
 current is shut off, and appears again when the current 
 is turned on. The electromagnet is the basis of many 
 household devices, some of which we are now going to 
 study. 
 
 Experiment. To make an electromagnet. 
 
 Materials: Dry cell. Push button. Insulated No. 20 copper wires. 
 Soft iron rod three inches long. Compass. Small iron tacks. 
 
 Method and Result: (A] Connect one pole of the cell to one screw of the 
 push button. Connect the other wire to the other pole of cell and 
 other screw of push button. Bring a portion of the wire down over and 
 parallel to the compass needle. Press the button to cause an electric 
 current to flow through the wire. Result? The current flows through 
 the wire toward the zinc pole of the cell. Make diagram to show 
 direction of the current through the wire, and which way the north 
 end of compass needle is deflected. (B) Wind the insulated copper 
 wire in close layers around the soft iron rod, remove the rod, connect 
 the ends of the coil into the electric circuit. Hold one end of the coil 
 near the north pole of the compass needle. Press the button to pass 
 an electric current. Result? Hold the other end of the coil near 
 the north end of the compass. Result? Make a careful diagram 
 showing the windings of the coil and connections to the cell. Let 
 arrows indicate the direction of the current in the wire. Label the 
 north and south poles of the coil. Put the iron rod inside the coil and 
 test again. Result? 
 
 Conclusion: How can you make an electromagnet? What rule can you 
 make to show the relation between the direction of the current of 
 electricity around the coil and the polarity of the coil? 
 
 An electric bell system. The essential parts of the 
 electric bell system are the bell, connecting wire, the but- 
 ton, and a source of electric current, which usually is the 
 
350 HOW ELECTRICITY IS USED IN THE HOME 
 
 dry cell. The button is a device for making and break- 
 ing the circuit. When you press the button you connect 
 the parts of the wire which at other times are separated 
 by an air space. Electricity can flow only when there is 
 a complete metal circuit from one pole of the battery 
 back to the other pole. The wire used must be insulated 
 to prevent leakage and short circuits, should the wire 
 happen to come in contact with metal or wet wood, or two 
 parts of the wire come together. 
 
 Experiment. To demonstrate the electric bell. 
 
 Materials: Electric bell. Electric cell. Wires. Push button. 
 Method: (A) Study the bell. Make out these parts : two binding posts, 
 
 electromagnet, armature, spring, contact post, contact screw, hammer, 
 
 gong. Trace the wire connection through the different parts from 
 
 one binding post to the other. 
 Note: In some bells a part of the wire circuit is omitted, and the base 
 
 of the bell carries the current from one part of the bell to one of the 
 
 binding posts. Is that the case with the bell in hand? 
 
 Connect bell, cell, and button in circuit. Adjust contact screw if 
 
 necessary. Make the bell ring. 
 Explanation: Explain in detail just why the bell rings. Make diagram 
 
 and trace, using arrows, the passage of the current from the cell back 
 
 to the cell. 
 
 How the bell works. The bell itself consists of the base 
 support, binding posts, electromagnet, armature, hammer, 
 spring, contact post, and gong. These parts are all shown 
 in the diagram. The wires from the battery and button 
 are connected to the two binding posts ; the current then 
 goes to the electromagnet, to the spring and armature, 
 to the contact post, and thence back to the other bind- 
 ing post. A strip of platinum on the armature makes 
 contact with a platinum point from the contact post. 
 These two pieces of platinum are held in position touching 
 each other by the spring when no current flows. 
 
Now suppose the circuit is closed by some one press- 
 ing the push button. A current flows through the entire 
 circuit. The electromagnet attracts the soft iron arma- 
 ture and pulls it away from the contact point at P, mak- 
 ing a gap or break 
 in the circuit. The 
 current instantly 
 stops, the magnet- 
 ism disappears, the 
 spring (S) brings the 
 armature back and 
 closes the circuit, a 
 current flows again, 
 and everything is re- 
 peated. This back- 
 ward and forward 
 movement of the 
 armature causes a 
 similar vibration of the hammer which strikes the gong 
 on every pull of the magnet. This vibration and result- 
 ing ringing of the bell continues as long as the button 
 is pressed. 
 
 Sources of current. The dry cell has about the same 
 strength as the wet cell, which is still used to some ex- 
 tent. For the usual house circuit two cells will be ample 
 and they should be joined, carbon (inside pole) of one to 
 zinc (outside pole) of the other. Either one of these types 
 of cells needs renewal or replacement from time to time. 
 Where electricity is used for lighting it is possible by in- 
 stalling a special device for reducing its pressure, to use 
 it for the doorbell system. The device used is called a 
 transformer. A transformer made for bell ringing circuits 
 
 The electric bell system. 
 
352 HOW ELECTRICITY IS USED IN THE HOME 
 
 can be bought for one or two dollars. The cost of opera- 
 tion is about the same as for renewals of batteries in the 
 older systems, but there is no trouble about having to re- 
 new batteries, which as a rule means an interval of time 
 when the bells will not ring. 
 
 The telephone. -- The telephone can almost be called 
 the errand boy of the household. It is one of the big- 
 gest of labor savers. There are a number of complicated 
 
 electrical devices in- 
 volved in the com- 
 plete equipment. 
 The receiver itself 
 has an electromagnet 
 in it and the vibra- 
 tion of an iron disk, 
 somewhat similar to 
 the vibration of the 
 armature of the elec- 
 tric bell, causes sound 
 waves which we hear. 
 A more complete ex- 
 planation of the tele- 
 phone will be given 
 when we study com- 
 munication at a fu- 
 ture time. 
 
 Commercial mo- 
 tors in the home. - 
 The importance of 
 the electric motor in 
 
 the home can well be appreciated when one stops to think 
 of the hard hand labor which is replaced by motor-driven 
 
 Electric control of sewing machine. Find the motor 
 which drives the machine 
 
THE VACUUM Ul^AlM^K AINJJ 
 
 353 
 
 washing machines, ice cream freezers, grinding wheels, 
 sewing machines, vacuum cleaners, and ironing machines. 
 They are inexpensive for the amount of work they do, 
 and save the strength of the housekeeper for other impor- 
 tant duties. 
 
 The vacuum cleaner and sweeper. The electric 
 vacuum cleaners are of two types. One produces a vacuum 
 by means of an air 
 pump of the piston 
 type, the other by 
 means of a fan. A 
 higher vacuum can 
 be produced with 
 the pump; and yet 
 a very high vacuum 
 is not needed: in 
 fact, it has several 
 disadvantages. A 
 strong vacuum is hard on the rugs and carpets, or any 
 cloth which is being cleaned. 
 
 The principle of vacuum cleaning is easily demonstrated 
 by holding the end of a glass tube near a loose ball of 
 paper (C) and drawing up the piston (A). A vacuum is pro- 
 duced in the tube, and air rushing into the tube pushes the 
 paper along with it. By making the opening (0) smaller 
 by using a stopper with a small tube, sand may be 
 forced into the tube, and if a piece of muslin cloth (m) 
 is fastened over the inside of the stopper near the end of 
 the larger tube, this will hold the sand and dirt which 
 enters, but will allow the air to pass on. This illustrates 
 the use of the bag for holding the dirt in the pump cleaners. 
 In the fan cleaners, however, the dirt and air are blown 
 
 H.-WHIT. CIV. SCI. IN THE HOME 23 
 
 To show the principle of vacuum cleaning. 
 
354 HOW ELECTRICITY IS USED IN THE HOME 
 
 into the bag. The dirt is held here by the tight, close mesh 
 of the cloth, but the air passes out into the room again 
 after being filtered through the cloth. 
 
 For thorough cleaning a vacuum of T V to -f of an at- 
 mosphere is desirable, but such a high vacuum makes the 
 
 tool stick to the 
 carpet and causes 
 rapid wearing. For 
 ordinary sweeping 
 where it is desired 
 to remove only the 
 surface litter, a vac- 
 uum of T V of an 
 atmosphere is suffi- 
 cient. The low vac- 
 uum machines are 
 termed "vacuum 
 sweepers " by some, 
 and the high pres- 
 sure machines "vac- 
 uum cleaners." 
 There are numerous 
 hand-driven vac- 
 
 uum sweepers on 
 the market. These 
 give a lower vacuum, 
 as a rule, than the 
 electrically driven ones, and yet they are satisfactory 
 for superficial sweeping. Carpets and rugs cleaned by 
 " sweepers " need removal and beating occasionally. 
 
 Electric heating devices. Many modern homes now are 
 equipped with electric toasters, grills, coffee percolators, 
 
 Vacuum cleaning system. 
 
ELECTRIC HEATING DEVICES 
 
 355 
 
 Showing the resistance wires in an electric 
 stove. 
 
 chafing dishes, heating pads, curling irons, even with water 
 and room heaters, and electric ranges. However, the electric 
 flat iron is by far the most popular electric device so far intro- 
 duced into the home . The 
 principle of electric heat- 
 ing is practically the same 
 in all of them. All con- 
 ductors resist the flow of 
 electricity. The electrical 
 energy used in overcoming 
 the resistance becomes 
 heat. Some metals, like 
 German silver and nich- 
 rome, offer much greater 
 resistance than copper does. For that reason a short 
 length of nichrome wire would give as much heat as a much 
 longer copper wire of the same diameter. It is advantageous 
 then to use a wire of very high resistance in heating de- 
 vices where the heat is produced by electricity. You re- 
 member when studying about electric lights how along wire 
 
 was heated by an elec- 
 tric current. When 
 the wire is in position 
 in the base of a flat- 
 iron it is covered with 
 an enamel which is 
 baked on so that the 
 wire cannot move out 
 of position or touch 
 other parts of the wire. The heating element of the coffee 
 percolator and other devices is made essentially in the 
 same manner. The electric iron should have a switch 
 
 Electric heating pad. 
 
356 HOW ELECTRICITY IS USED IN THE HOME 
 
 close to the iron, also a pilot light on the wall socket 
 where it is attached. This pilot light will always glow 
 
 An electrically prepared meal. What heating devices do you see ? 
 
 when the current is left on. Many fires are caused every 
 year by carelessness with electric irons. The pilot will 
 suggest to you the danger, and you will be less likely to 
 
 Electric toaster. 
 
 Electric iron. 
 
SCORE CARD 357 
 
 omit turning it out when you leave it. It is a good habit 
 to form always to disconnect at the socket. 
 
 The score card. This score card will help you to be- 
 come efficiency experts in your own homes. Mother could 
 be saved a good deal of labor by the introduction of some 
 of the machines mentioned here and no doubt your home 
 life would be much pleasanter if some of the devices listed 
 here were added to your own list. The list is incomplete, 
 so space has been given for you to credit others. If you 
 have a number of them, talk with your teacher and see 
 if you can substitute some you have for others you do not 
 have which are mentioned on the card. 
 
 REFERENCE BOOKS 
 
 Barber, General Science, Chapter X. Henry Holt and Company. 
 
 Caldwell and Eikenberry, General Science, Chapter XIX. Ginn and Company. 
 
 Clark, An Introduction to Science, Chapters XXII, XXIII, XXIV. American Book 
 Company. 
 
 Clark, The Care of a House, Chapter XI (Teacher's use). The Macmillan Com- 
 pany. 
 
 Collins, The Book of Electricity (Wiring project). D. Appleton and Company. 
 
 Fall, Science for Beginners, Chapters XXX, XXXI, XXXII. World Book Com- 
 pany. 
 
 Hessler, The First Year of Science, Chapter VIII. Benj. H. Sanborn Company. 
 
 Hodgdon, Elementary General Science, Chapter XI. Hinds, Hayden, and Eldridge 
 Company. 
 
 Jameson, The Compass, the Signpost of the World. Taylor Instrument Company, 
 Rochester, N. Y. 
 
 Shafer, Everyday Electricity. Harper and Brothers. 
 
 Van Buskirk and Smith, The Science of Everyday Life, Project XVI. Houghton 
 Mifflin Company. 
 
 Woodhull, Electricity and its Everyday Use (For projects). Doubleday, Page and 
 Company. 
 
358 HOW ELECTRICITY IS USED IN THE HOME 
 
 SCORE CARD. DEVICES FOR CONVENIENCE AND LABOR SAVING 
 IN MY HOME 
 
 SCORE 
 
 Perfect 
 Score 
 
 Electric fixtures 
 
 Doorbells 2 
 
 Telephone 5 
 
 Vacuum cleaner 3 
 
 Adjustable fixtures for reading 2 
 
 Electric iron i 
 
 Electric cooker or heater i 
 
 Other devices (name them) i 
 
 Cleaning helps 
 
 Carpet sweeper 2 
 
 Dustless mop and dusters i 
 
 Washing machine or vacuum suction washer .... 2 
 
 Clothes wringer i 
 
 Gas iron i 
 
 Wall ironing board i 
 
 Other devices (name them) . 2 
 
 Kitchen helps 
 
 Fireless cooker 2 
 
 Gas, electric, or blue flame stove 3 
 
 Dishwashing machine | 
 
 Dish drying rack ^ 
 
 Bread mixer \ 
 
 Meat chopper \ 
 
 Egg beater \ 
 
 Steam cooker \ 
 
 Ice cream freezer \ 
 
 Knife sharpener \ 
 
 Other devices (name them) . i 
 
 Other helps 
 
 Sewing machine 5 
 
 Electric motor or water motor for machine .... 3 
 
 Other devices (name them) ....:.... 2 
 
 Tools and workroom 
 
 Tool box and full set of tools 3 
 
 Carpenter's bench . . . . , i 
 
 Proper workroom i_ 
 
 TOTAL 50 
 
CHAPTER XXIII 
 
 HOW ELECTRICITY IS CONTROLLED IN OUR 
 HOMES 
 
 Problems. i. To determine how electricity is produced 
 and controlled. 
 
 2. To find out what effect different lengths and sizes of 
 wire have on the electric pressure and current. 
 
 3. To find out how the house is protected from excessive 
 currents. 
 
 4. To learn how to read the electric meter. 
 
 Experiment. i. Make a wet cell and show presence of an elec- 
 tric current. 
 
 Project I. To INSTALL A NIGHT LIGHT IN MY BEDROOM. 
 
 1. Purpose of the light? 
 
 2. How will you arrange wiring? Locate battery, switch, and 
 lamp. Make plans of connections. 
 
 3. What materials are needed? Cost? 
 
 4. Install the light system and make a report on it. 
 
 Suggested Projects. 
 
 1. THE TRANSFORMER VS. DRY CELLS TO OPERATE A DOORBELL. 
 
 Find the cost of a doorbell transformer for use on electric light cir- 
 cuit, and cost of operating it. Find cost of operating doorbells on 
 dry cells. Considering cost and convenience of uninterrupted serv- 
 ice, which system would you recommend ? 
 
 2. FIND THE COST OF OPERATING VARIOUS ELECTRIC DEVICES PER 
 
 HOUR. Learn how to measure small amounts of electric power by 
 timing the revolutions of the dial in the wattmeter. 
 
 359 
 
360 
 
 HOW ELECTRICITY IS CONTROLLED 
 
 How electricity is led about in the home. - Although 
 electricity has become a valuable servant and a cheap 
 one where water power is available, yet it is a dangerous 
 servant as well. We have often heard of fires that were 
 caused by crossed wires making a " short circuit " or by 
 
 accidents from electric 
 wires of heating devices, 
 or of people shocked to 
 death by receiving a 
 charge of electricity in 
 their body. We know 
 that the wires which 
 carry electricity must be 
 carefully guarded by a 
 layer of what we call in- 
 sulating material, that is, 
 something that will not 
 readily conduct the elec- 
 tricity. We have all 
 learned enough about 
 the conduction of heat to 
 
 know that some materials are good and some are poor con- 
 ductors. Likewise certain metals will conduct electricity, 
 while other substances, like rubber, will not conduct it, 
 hence the latter are used in insulation. 
 
 Current electricity. If we rub wax rapidly with a 
 piece of woolen cloth we can electrify it. The wax is then 
 said to be charged with electricity. A charged body such 
 as this, is one in which electricity is at rest. To be sure, 
 the amount in the wax is very, very small, but if we were to 
 connect two oppositely charged bodies, negative and posi- 
 tive, with a good conductor, such as a metal wire, elec- 
 
 The sal ammoniac cell. 
 
ELECTRIC CELLS 
 
 361 
 
 4 Posts 
 
 BmdmeS 
 
 i to 
 
 CccrboTL 
 
 5cci\oL 
 Sawdust 
 
 tricity would flow for just an instant from one body to the 
 other. Electricity in motion as this is, is called current 
 electricity. This is the kind of electricity which we use 
 in ringing our doorbells, in running our motors, and in 
 lighting our homes. We have all seen what electricity 
 will do, and now we will try to understaad how to produce 
 it, and some other things which we can do with it. 
 
 Electric cells. You may have heard the terms, dry cell 
 and wet cell, and doubtless some of you have seen them in 
 your homes, as these two 
 kinds of cells are used 
 to ring electric doorbells. 
 The wet cell is made by 
 nearly filling a jar with 
 a saturated solution of 
 sal ammoniac. In this 
 are suspended side by 
 side, but not touching 
 each other, a large car- 
 bon plate and a zinc rod. 
 Electricity is formed at 
 the expense of chemical 
 energy, and the zinc rod 
 which is destroyed must 
 be replaced from time 
 to time. 
 
 In the dry cell, the 
 zinc used is placed on 
 the outside of the cell while the carbon is a large rod in 
 the center. Between these are the chemicals, a paste of 
 sal ammoniac being placed next the zinc, and a layer of 
 manganese dioxide around the carbon. Dry cells, because 
 
 is WJ*?^ 
 
 Sakxmmoniac 
 and. PI aster 
 y 'Paris 
 
 'Porovcs Tkpe 
 -"Manganese 
 DioxicLe aria. 
 'Powclerect 
 Cccrrboru 
 
 Heavy Tar Paper 
 
 Section of a dry cell. 
 
362 HOW ELECTRICITY IS CONTROLLED 
 
 they are more convenient to handle, have come to replace 
 to a large extent the wet cell in our homes. 
 
 What produces the electric current ? When an 
 electric cell has been used for a long time, it may refuse to 
 produce any more current. In the case of the wet cells, 
 you will very likely find that one of the plates in it has 
 been used up. This suggests that some vigorous chemical 
 action has taken place in the cell between the solution and 
 the plates. This is true. The cell is really a device by 
 which energy resulting from this chemical action in the 
 cell is changed into electrical energy. 
 
 Experiment. To make a wet cell and show presence of electric current. 
 
 Materials: Carbon. Zinc. Jar for sal ammoniac cell. Sal ammoniac. 
 Electric bell or compass. Wires. 
 
 Method: Fill the jar with water to the mark and add sal ammoniac 
 and stir. Continue adding sal ammoniac until a saturated solution 
 is obtained. Put zinc and carbon in cell. Join wires to poles. Test to 
 see if a current is produced by joining an electric bell in circuit or 
 test wire of closed circuit with compass. How can you detect a current 
 in a wire by means of a compass? 
 
 Result and Conclusion: What is the result? What are the essentials of 
 a wet cell? 
 
 Wire resistance to electricity. Anybody knows that 
 if he wants to empty a tank of water a short pipe would 
 empty it quicker than a long one of the same diameter. 
 This is explained by the fact that a long pipe has more 
 surface to rub against the flowing water, and this produces 
 iriction, thus allowing less water to get out in a given time. 
 There is a very close parallel to this in the case of elec- 
 tricity passing through wires. If you connect the poles 
 of one cell with a long wire and then the poles of the other 
 cell with a shorter wire of the same diameter, the elec- 
 tricity will be discharged through the shorter wire more 
 
ELECTRICAL PRESSURE 
 
 363 
 
 rapidly. The reason for this is that the longer wire offers 
 greater resistance to the current, so that less current flows ; 
 but as in the case of the tank of water, the current will 
 flow for a longer time. 
 
 You also know that a pipe of large diameter will empty 
 a tank of water much quicker than one of small diam- 
 eter. A large tube (or pipe) carries a larger current of 
 water than a small one. Just so with electric currents. 
 
 Pipe 
 
 (low resistance) I/or^PipeGnghresistaT 
 Heavy "Flow 
 
 Short Wire I/ongWire, 
 (low resistance) ("high, resistance 
 j Large 3m a 11 
 
 Water analogy: short and long wire resistance. 
 
 The wire with a large diameter permits a larger flow of 
 electricity than one of small diameter. 
 
 Electrical pressure. Suppose you have two tanks of 
 water, one holding a large amount, and the other a small 
 amount and that the water in them is kept at the same 
 level. The water running from the faucets at the bottom 
 will have the same pressure just so long as the level is 
 maintained evenly in the two, and if the openings of the 
 two faucets are of the same size, equal streams or currents 
 of water will flow from them. The electrical pressure 
 (called voltage) is independent of the size of the cells used. 
 The cell of a small flashlight may have just as high pres- 
 sure or voltage as does a common dry cell which has a 
 
HOW ELECTRICITY IS CONTROLLED 
 
 pressure of about 1.5 volts. A volt is the unit used in 
 measuring electric pressure, or the force which causes 
 electricity to flow through a conductor. An instrument for 
 measuring voltage is called a voltmeter. 
 
 Electric current. If we use our tank again for com- 
 parison, we shall see that water pressure alone will not tell 
 us how great a flow of current may be obtained. The 
 size and length of the pipe help to determine this, be- 
 cause they regulate the resistance, and resistance is one 
 factor which determines the amount of water which flows. 
 
 Equal 
 Pressure 
 
 Pipe 1/argfe. T>ia . ^ \Pipe 5maU Dice 
 (Low re5istance.)|P^\ (High resi?tct 
 Heccv-y "Flow, 
 
 jl 
 
 
 (7"Uv. 
 
 i Ammeter 
 
 
 
 
 Dry 
 
 Equal 
 
 Dry 
 
 Cel 
 
 * 
 
 Voltage 
 
 Cell 
 
 U 
 
 
 y 
 
 Tlow. 
 
 Wire LargeDiameter Wire Simll Dia.. 
 (jow resistccixcje.) OughresistctJxcO 
 L-arcffe Guerrejxt, Small Current 
 
 Water analogy : relation of current to resistance in large and small wires. 
 
 This also holds in a similar manner with electricity. If 
 we have the poles of a cell connected by a wire of small 
 resistance, a large current will flow through it, but if the 
 resistance be great, a small current will flow. The unit 
 for measuring an electric current is the ampere, so named 
 after a French scientist. The instrument by which this 
 current is measured is the ammeter. 
 
 How to join cells for use in the home. There are two 
 ways in which we may join cells together so that we can 
 overcome resistance offered by wires. These are in series, 
 and in parallel. We can understand these terms best by re- 
 ferring again to our water tanks. Suppose we have three 
 
HOW TO JOIN CELLS FOR USE IN THE HOME 365 
 
 tanks of water at the same pressure, and connect them so 
 as to get a water column three times as deep as that of a 
 single tank. The water pressure will be three times that 
 of a single tank. If we join three cells in series, that is, 
 zinc to carbon, and connect a voltmeter in the circuit, 
 we shall find three times as much pressure recorded as when 
 
 Water Xante Aeries 
 Pressure \$ Increases 
 
 WaterTahksiix'Parallel .'Pressure ofOneTank 
 
 Water analogy to illustrate joining cells in series and in parallel. 
 
 a single cell is attached to the voltmeter. A high pressure 
 (high voltage) will give us a larger current (in amperes) 
 through the bell, motor, or light than we can get from the 
 low pressure. When long wires are used in connecting 
 an electric bell greater voltage is required to overcome the 
 resistance of the long wire. This increased volta'ge can be 
 obtained by putting in one or two more cells joined in series. 
 A bell can be made to ring louder and a motor to run 
 faster by this same method. 
 
366 HOW .ELECTRICITY IS CONTROLLED 
 
 When we join our three tanks of water at the same level, 
 we increase the capacity to furnish a current of water, 
 although it has no greater pressure than the single tank. 
 We may join three cells in parallel by connecting all the 
 zinc poles to one wire, and all the carbon poles to another 
 wire, then we. join these two wires where we wish to use 
 the -current. If we attach a single cell to the voltmeter 
 and read the voltage, and then later attach three cells 
 joined in parallel to the voltmeter and read the voltage, 
 we find it to be the same. Any number of cells joined in 
 parallel have just the same voltage as a single cell. With 
 the same size of opening for the single and the triple water 
 tanks the water would flow from the triple tank for a longer 
 time. It has a larger reservoir, so with the cells joined in 
 parallel, if the voltage of one cell gives all the pressure you 
 need, you can get much longer service from several cells 
 joined in parallel than you can from one cell. These 
 explanations should serve to make it possible for you to 
 now use the batteries in your own home intelligently. 
 
 The life of a cell. If you have a large outlet to a tank 
 of water, it will quickly drain the tank. The less re- 
 sistance you have in the circuit of an electric cell, the 
 greater will be the flow of the current, and since the ca- 
 pacity of a cell is limited, its life will be shortened. The 
 practice of connecting two poles of a cell by a short piece 
 of metal quickly spoils the cell. If you wish your cell to 
 work for you for a long time, be sure not to allow any 
 " short circuits." 
 
 What is a "short circuit"? We have all used the 
 term " short circuit," and now let us try to understand 
 fully what it means. The circuit of electricity is the 
 complete path which the current must take from the cell 
 
c 
 
 FUSES 367 
 
 out around the wire, through the bell, or other instru- 
 ment, and back to its starting point. Let us, for example, 
 take the lighting system in our home. Current is brought 
 into the house by one wire, and returns to its source by 
 another. If in the 
 diagram, A and B 
 connect our house 
 circuit with the city 
 supply, when the 
 switch is closed we 
 
 are able tO light any Diagram of lighting system. 
 
 one or all of the lights L, L', and L" . These lamps have a 
 high resistance to electricity, and allow not more than one 
 to three amperes of current to flow through the circuit. 
 Now suppose the bare ends of the wires C and D, which 
 have low resistance, are brought together. This " short 
 circuit " would reduce the resistance several hundred times, 
 and the current would be increased enormously. 
 
 There is a real danger from short circuits. Not only 
 may the insulation on wires be burned off, but the build- 
 ing may be set on fire. If any part of the wire AC is con- 
 nected metal to metal with any part of BD, or if the two 
 separated metal parts of the lamp circuit be joined by a 
 piece of metal, a short circuit results, with its great in- 
 crease of heat and corresponding danger from fire. When 
 the dry cell is " short circuited " there is much less danger 
 from fire than in the case of the electric light circuit, be- 
 cause the cell has a very small capacity. Yet this cell 
 will heat a short length of small iron or german silver 
 wire red hot, and so might be a source of danger. 
 
 Fuses. If we were to take a number of different metals 
 and expose them to heat, we would find that some of them 
 
3 68 
 
 HOW ELECTRICITY IS CONTROLLED 
 
 TXIIC- A. 
 PORCELAIN 
 FUSE WIRE 
 
 SCREW CONTACT 
 
 PORCELAIN 
 
 "POINT 
 
 melt at a much lower temperature than others. Lead, 
 for example, melts very readily. If you have seen the 
 plumber solder pipes, you have noticed that he has a copper 
 instrument which is used to melt the solder, so you know 
 that red hot copper can melt solder. Such low melting 
 metals are used in making fuse wires. If a fuse wire is made 
 
 a part of the elec- 
 trical circuit in a 
 house, it would evi- 
 dently melt if heated 
 to a point much 
 below that which 
 would melt the cop- 
 per wires carrying 
 electricity. Such a 
 c.Link wire placed in the 
 house circuit is 
 known as the fuse. If a short circuit is produced, the 
 fuse instantly melts, and thus the electricity is cut off from 
 the house, and danger from fire prevented. If we have 
 electric lights in our home, we should all know the loca- 
 tion of the fuse box, and we should understand how to 
 put in the fuse plugs in case they burn out. Of course, 
 we must take care first to turn back the switch, thus cutting 
 off all the electricity from the house, before we attempt to 
 do this. 
 
 Measuring electricity. Each one of us should learn 
 to read the dials on the ordinary electric meter, which is 
 part of the equipment of every house that takes its elec- 
 tricity from the city supply. The meter is called the 
 wattmeter, and the readings are made in kilowatt hours. 
 For example, if we have ten lamps, each marked twenty- 
 
 Fuses : A, Cartridge fuse ; B, Socket fuse ; 
 fuse. 
 
MEASURING ELECTRICITY 369 
 
 five watts, and they are all lighted for an hour, we would 
 then be using 10X25 or 250 watts an hour, and in five 
 hours this would be 5X250 or 1250 watt hours. The watt 
 is the unit by which we measure electrical energy. One 
 thousand watts make one kilowatt and one kilowatt used for 
 one hour equals one kilowatt hour. Electricity for the ten 
 lamps, using 1250 watt hours or 1.25 kilowatt hours, would 
 cost, at twelve cents per kilowatt hour, fifteen cents per 
 hour. A study of the diagram shows that of the four dials, 
 the one to the left moves the least, while the one to the right 
 moves the fastest. The four dials indicate thousands, 
 hundreds, tens, and units. Study the diagram. If the 
 thousands hand is between i and 2, it will indicate 1000 ; 
 if the hundreds hand is 
 between 6 and 7, it in- 
 dicates 600; if the tens 
 hand is between 5 and 
 6, that will be 50, and 
 the units hand, between 
 
 , . , Wattmeter dials. 
 
 9 and o, is read 9, 
 
 making a total of 1659 kilowatt hours. If the previous 
 reading had been 1610, that would mean that we have used 
 49 kilowatt hours since the meter was last read. We have 
 already shown under the chapter on lighting some ways 
 to reduce the 'electric light bill through the use of the 
 tungsten lamps, but if our meter bill seems high, we 
 should inquire into the cause. The large bill may come 
 from some leakage, from a forgotten light in a closet or 
 attic left burning, from defective wiring which may 
 allow a current to flow when no lights are in use, and 
 rarely from an error in the meter itself, or in the reading 
 of the meter by the man sent from the electric company. 
 
 H.-WHIT. CIV. SCI. IN THE HOME 24 
 
370 HOW ELECTRICITY IS CONTROLLED 
 
 REFERENCE BOOKS 
 
 Bachman, Great Inventors and Their Inventions (Edison). American Book Company. 
 
 Baker, Boys' Second Book of Inventions. McClure Phillips Company. 
 
 Book of Knowledge, Articles on Electricity. Grolier Society. 
 
 Butler, Household Physics. Whitcomb and Barrows. 
 
 Caldwell and Eikenberry, General Science, Chapter XVII. Ginn and Company. 
 
 Clark, Introduction to Science, Chapter XXIV. American Book Company. 
 
 Clark, The Care of a House, Chapter XI (For teachers). The Macmillan Company. 
 
 Croft, Wiring for Light and Power (For teachers). McGraw Hill Book Company. 
 
 Knox, All About Electricity. Funk and Wagnalls. 
 
 Lynde, Physics of the Household, Chapters XIX, XX, XXI. The Macmillan 
 Company. 
 
 Morgan, The Boy Electrician (For projects). Allyn and Bacon. 
 
 New International Encyclopedia, for lives of great discoverers of electricity. Dodd, 
 Mead, and Company. 
 
 Romance of Modern Electricity. J. B. Lippincott Company. 
 
 Tappan, Wonders of Science, "Interviews with Edison." Houghton Mifflin Com- 
 pany. 
 
 Van Buskirk and Smith, Science of Everyday Life, Project XII. Houghton Mifflin 
 Company. 
 
PART VII. RECREATION IN THE 
 HOME 
 
 CHAPTER XXIV 
 INDOOR RECREATION 
 
 Problems. i. To learn the nature of sound and the re- 
 lation of our voice and ears to sound. 
 
 2. To learn simple principles underlying music and 
 musical instruments. 
 
 3. To cultivate the habit of reading good books. 
 
 4. To see how to get the most home enjoyment in stories 
 and games. 
 
 5. To learn some ways to have fun with mechanical and 
 electrical toys. 
 
 Experiments and demonstrations. i. To show that sound is due 
 to vibration. 
 
 2. To demonstrate static electricity. 
 
 Project I. To UNDERSTAND THE MECHANISM OF THE PIANO 
 
 AND THE PIANO PLAYER. 
 
 1. The wires, relation of sizes, lengths, tension. How tuned? 
 
 2. Key action? Diagram to show it. Keyboard? Octaves? 
 
 3. Pedals. Action and control? 
 
 4. Player pump air pressure or exhaust. How does air con- 
 trol key action? Use of the music roll? 
 
 37i 
 
372 INDOOR RECREATION 
 
 Suggested Projects. 
 
 1. TO LEARN HOW TO BE A VENTRILOQUIST. 
 
 2. TO BUILD A CANTILEVER BRIDGE WITH A MECCANO OUTFIT. 
 
 3. TO LEARN TO PLAY SOME MUSICAL INSTRUMENT. 
 
 4. TO LEARN TO SING OR TO TELL A STORY WELL. 
 
 5. TO START A STAMP COLLECTION AND SPECIALIZE IN THE STAMPS 
 OF SOME ONE COUNTRY. 
 
 6. TO LEARN TO DO ELECTROPLATING. 
 
 The place of recreation in our lives. We hear a 
 great deal nowadays about the eight-hour day. The 
 average day of the working man or the business man or 
 woman should give eight hours for work, eight hours 
 for sleep, and eight hours for other duties of life, includ- 
 ing recreation. In our school day, even more time is 
 allowed for play. But much of this time is spent away 
 from home. We are getting far too fond of spending 
 time away from home, especially in the evenings. How 
 much better it would be for every boy and girl to feel 
 that two or three hours in the evening should be spent in 
 the family circle. Too many movies and not enough home 
 life are the choice of the average boy and girl of to-day. 
 We usually have access to the well-lighted reading room 
 of the public library. But nothing can take the place of 
 home, and the remembrance of the pleasant evenings spent 
 before the open fireplace, or playing games, or reading 
 around the comfortable lamp in the living room, should 
 be the heritage of every boy and girl who reads this book. 
 
 Sound in relation to our home life. Have you ever 
 stopped to think what our home life would be without 
 sound? No mother's or father's voice, no conversation at 
 the table, no music, vocal or instrumental, no phonograph, 
 none of the hundreds of pleasant and interesting events 
 
WHAT IS SOUND? 
 
 373 
 
 which follow the use of our voices, for withou: sound 
 means without voice. You will be glad, now, to get a little 
 information about sound in its relation to human beings. 
 
 What is sound ? We know in a general way that we 
 make sounds by means of certain cords in our throats, 
 
 Enjoying life at home. 
 
 called the vocal cords, and that sounds affect our ears, which 
 in turn communicate them to the brain, and we get the 
 sensation we call sound. But this does not explain how 
 sound originates. 
 
 Experiment. To show that sound is due to vibration. 
 
 Materials: Tuning fork. Pith ball on end of a thread. Glass of water. 
 
 Method and Results: Strike the prong of a tuning fork on a block of wood. 
 Rest the handle end against the table. Let the pith ball suspended by 
 the thread come in contact with the prong. Result ?* Strike the 
 prong again and touch the surface of the water with it. Result? 
 Pluck a stretched string. Touch with the pith ball. Result? 
 
 Conclusion: Do these bodies produce sound except when they are vi- 
 brating? How does a body produce sound? 
 
374 
 
 INDOOR RECREATION 
 
 When the alarm clock goes off in the morning, it makes 
 no difference what part of the room it is in. Sound travels 
 from it in all directions. If we obtain a tuning fork, an 
 instrument which gives a musical tone, we shall be able 
 to learn something about how sound is produced. If 
 we strike the prongs of the fork on a block of wood, we 
 are all able to hear the sound, although we cannot notice 
 that the tuning fork looks any different than it did before 
 it was struck, but if we hold a pith ball suspended from a 
 string so that it touches the prong of the fork, after the 
 fork has been struck, we notice that the pith ball moves 
 
 violently away from the 
 fork, as if struck by a blow. 
 If we now stick the end of 
 the fork into a vessel of 
 water, we find a fine spray of 
 water thrown from the sur- 
 face. Evidently the fork is 
 in quite rapid motion. As 
 a matter of fact, it is vibrat- 
 
 How to show that a sounding tuning fork 
 is in motion. 
 
 ing several hundred times a 
 second, and in vibrating, it 
 strikes the air just as it strikes the water, and sets up 
 little waves in the air. Just as waves move on the sur- 
 face of water when we drop a stone in, becoming wider 
 and wider as they move away from their source, so a 
 body that makes sound, as the tuning fork, sends these 
 waves off into the air. Only we must remember that 
 instead of the waves moving, as on the surface of the 
 water, in one plane only, these are moving away in all 
 directions from the sounding body, each wave making a 
 hollow sphere in the air. 
 
DIFFERENCES IN THE PITCH OF THE VOICE 375 
 
 Vocal cords. 
 
 Our voice. A study of the figure will show us the lo- 
 cation of the vocal cords, which are instrumental in 
 producing sound. They are composed of two thin struc- 
 tures stretching from front to back across the voice box, 
 near the top of the lar- 
 ynx. They are attached 
 to the side walls. By 
 means of muscles the 
 tension of these cords 
 may be changed and the 
 size of the opening be- 
 tween the two outer 
 edges may be made larger or smaller. In deep breath- 
 ing, for example, they lie flat against the side walls of 
 the larynx, thus allowing a full entrance of air. But 
 when we make a sound they come very close together 
 so that only a narrow opening is made between them. 
 The tightly drawn cords are set into vibration by the 
 passing air, and sound results. 
 
 Differences in the pitch of the voice. A child's voice 
 is shrill or high pitched. This is because the larynx is 
 
 narrow and the vocal 
 cords are short. It 
 is a well-known fact 
 that long wires or 
 strings, when vibrat- 
 ing, give a much 
 lower and deeper 
 tone than do short strings. This is easily seen in picking 
 the mandolin or banjo. If you put your fingers on the frets, 
 making the string shorter, it gives a note of higher pitch. 
 When a boy's voice is breaking or changing, it means there 
 
 The pitch of a string is raised by shortening the wire 
 and by increasing the tension on it. 
 
376 INDOOR RECREATION 
 
 is a sudden growth of the larynx, and in consequence, a 
 lengthening of the vocal cords. This change is so rapid 
 that there is an uncertainty in the boy's control of his vocal 
 cords, and the break in the voice occurs. 
 
 How we talk. Human speech seems very wonderful, 
 and yet it is all accomplished after we have learned how 
 to control the voice with absolute unconsciousness on our 
 part. When we speak in a monotone, all of our words 
 are of the same pitch, and yet we can distinguish differ- 
 ences in the sound of the different words. This is due 
 to the quality of sound. As the sound waves pass through 
 the mouth, they are changed in quality by movements 
 of the tongue, soft palate, cheeks, jaws, and lips. A 
 study of your own voice before a mirror while you make 
 the sounds a, e, i, o, and u, will show you that in each 
 of these sounds, a different position of the parts of the 
 mouth and throat are assumed. It is excellent practice 
 for any one who is troubled in enunciation to thus stand 
 before a mirror and practice making these sounds, for it 
 is only by practice that our mouth parts unconsciously 
 get the habit of forming sounds correctly, and thus we 
 learn to speak clearly. Get this habit of clear enuncia- 
 tion while you are in school, and it will remain with you 
 as a good habit through life. 
 
 How we hear. Sound and speech would not be of 
 much use to us if we could not hear. The ear is far too 
 complicated and delicate an organ for us to understand 
 at this time, although a study of the accompanying dia- 
 gram will give us some idea of how sound is heard. The 
 outer ear, which is simply an organ to help gather the 
 sound waves, leads by means of a tube into the middle 
 ear. This is separated from the outer ear by a delicate 
 
HOW WE HEAR 
 
 377 
 
 membrane. If this membrane is broken, hearing is im- 
 paired, and therefore children should be very careful not to 
 stick a pointed instrument into the ear, and if anything gets 
 into the ear, they should not try to get it out themselves, 
 but should get help from some one who knows how to handle 
 the ear. In the middle ear are three tiny bones. These 
 serve as a bridge to carry the sound waves from the outer 
 ear into the inner ear. Waves hit against the membrane 
 
 Parts of the ear. Notice the three little bones in the middle ear. 
 
 and cause it to vibrate, and are transferred to the mid- 
 dle ear. Here deep in an opening in the bone of the 
 skull is an instrument a thousand times more delicate 
 than the most wonderful piano in existence. This in- 
 strument receives the sound waves and transfers them to 
 the brain. 
 
 The ear is also a balancing organ, and in many lower 
 animals has this function only. Our equilibrium is main- 
 tained by means of three so-called semi-circular canals 
 which are set into the opening at different angles. Those 
 men who wish to become aviators must have a perfect 
 
378 
 
 INDOOR RECREATION 
 
 sense of equilibrium, and if their semi-circular canals are 
 not in excellent condition, they cannot enter this arm of 
 government service. 
 
 Music and noise. We are all aware of differences in the 
 sounds that come to the ear which cause us to say, " This 
 is noise," or " This is music." These differences are due 
 to definite pitch relations and periodic movement of sound 
 
 f^= 
 
 
 f 
 
 
 
 
 
 
 
 \^= 
 
 "Name 
 
 ^F 
 ao 
 
 P 
 
 re, 
 
 n\i 
 
 O 
 A 
 
 sol 
 
 la 
 
 ti 
 
 do 
 
 I/etter* 
 
 C 
 
 D 
 
 
 
 I" 
 
 G 
 
 A 
 
 B 
 
 C 
 
 Tfumbep of 
 VibpatiorvS 
 persecoixcL 
 TDetfinruivcr 
 wiCKmideQe 
 C Cpiaixo) 
 
 258.7 
 
 290.3 
 
 3253 
 
 345.3 
 
 387.6 
 
 435 
 
 488.3 
 
 517.4 
 
 Standard of 
 the!hy,5icist 
 
 56 
 
 268 
 
 320 
 
 Mli 
 
 584 
 
 4261 
 
 480 
 
 512 
 
 The musical scale. 
 
 waves. The beating of a tom-tom and the monotonous 
 chant of a savage in his war dance are periodic, and have 
 a definite pitch, but they are not pleasing to our ear, 
 hence they cannot be classified as music to us, although 
 to the savage who makes them and enjoys them, they are 
 music. 
 
 The musical scale. Our music is built up on a series 
 of sounds having definite ratios of vibration. This is 
 called the musical scale. A study of the diagram below 
 shows the staff, with the names of the notes or letters 
 
STRINGED INSTRUMENTS 379 
 
 given these notes, with the number of vibrations that 
 each makes. This series of tones, which is used for all 
 kinds of musical instruments the world over, is known as the 
 musical scale. Each higher tone in the next scale will 
 have twice the vibration rate of that of the corresponding 
 letter in the scale shown in the diagram, and each of the 
 
 An instrument with many strings. Can you locate the strings which give the low tones ? 
 
 next lower scale will have half the vibration rate of the 
 corresponding tone in the scale shown. There are on the 
 piano and organ keyboard black keys which have inter- 
 mediate rates of vibration. These are the so-called sharps 
 and flats, and without these notes modern music would 
 be impossible. 
 
 Stringed instruments and how they make sound. - 
 We have already alluded to the fact that a note of low 
 pitch is caused by the vibration of a long string, while 
 
INDOOR RECREATION 
 
 notes of higher pitch are caused by the more rapid vibra- 
 tion of shorter strings. In stringed instruments, such as the 
 banjo, guitar, mandolin, violin, and cello, the musical 
 scale is made by cutting down the length of the string by 
 means of shortening it with the ringers. In the case of 
 the piano and harp, the strings are all made of varying 
 lengths, each producing its own tone. Just as we found 
 in changing the shape of our mouth and tongue we could 
 produce different qualities of tone, so the instrument 
 
 maker produces different quality by making his instru- 
 ments in different shapes. 
 
 The phonograph. The phonograph has become a very 
 important part of our home life, for though relatively 
 few of us can make music, most of us- enjoy it. The 
 phonograph is a musical device for reproducing sounds. 
 The original sounds are recorded as a fine wavy line on a 
 wax cylinder or plate. The records we buy are duplicates 
 of this original, or master record. The reproducing mech- 
 anism has a diaphragm capable of very delicate vibra- 
 tions. This is connected with a needle which rests on the 
 
GOOD READING AND WHAT IT MEANS 381 
 
 record. When the record is set in motion, the needle 
 follows the fine wavy line and is made to vibrate to cor- 
 respond with the vibrations of the original sound waves. 
 These vibrations are communicated to the diaphragm, and 
 this causes sound waves in the air, which come to us as 
 reproductions of the original sound. 
 
 Good reading and what it means. We have already said 
 that life is made up of bundles of habits. We form habits 
 by doing things when quite young, and you are now at an 
 age when you can form them most easily. Why not use 
 some of the time you spend in recreation in getting the 
 habit of reading good books and good magazines? Far 
 too many boys and girls limit their reading to the daily 
 newspaper or some of the various cheap weekly and 
 monthly magazines. Life will be far richer to you if in- 
 stead of feeding your mind upon trash, you use something 
 which will be of use to you later. It is simply a matter 
 of habit whether you read a number of poorly written 
 stories with very little of real interest in them, or whether 
 you form the habit of reading books that are really worth 
 while. What could be more absorbing, for example, than 
 Stevenson's " Kidnapped " or " Treasure Island," Scott's 
 " Ivanhoe," or Kipling's " Captains Courageous"? Such 
 books rank high as literature and at the same time are 
 as thrilling as you may desire. Some other stories of in- 
 terest to boys and girls are as follows : Kipling's " Just 
 So Stories," and " Jungle Books," Numbers One and 
 Two ; Poe's " The Gold Bug " ; Carroll's " Alice in Wonder- 
 land " and " Through the Looking Glass"; Arnold's 
 " Tom Brown at Rugby " ; Scott's " Ivanhoe " and 
 " Guy Mannering " ; Dickens' " Tale of Two Cities," 
 " Nicholas Nickleby," and " Pickwick Papers," the latter 
 
382 INDOOR RECREATION 
 
 if you want a good laugh ; Lanier's " King Arthur " ; 
 Pyle's " Robin Hood " ; Blackmore's " Lorna Doone." 
 For real fun read " Uncle Remus " and " Peterkin Papers " ; 
 Lear's " Nonsense Rhymes," and even " Little Black 
 Sambo." Girls will enjoy " Peter Pan," and Barrie's 
 " Little Minister," or " Sentimental Tommy," and we 
 never get tired of stories such as " Don Quixote " and 
 some of Shakespeare's plays. As for magazines, why not 
 make a rule of reading articles that interest you from 
 some good weekly such as the " Independent " or the 
 " Outlook," and boys' and girls' magazines such as " Youth's 
 Companion," " Saint Nicholas," and boy and girl scout 
 magazines. Boys will certainly enjoy " Popular Science," 
 and " Popular Mechanics." There are always plenty of 
 good monthlies to be obtained from the libraries and one 
 should get the habit of reading the stories in the " Cen- 
 tury " and " Harpers " rather than those of the many 
 trashy illustrated magazines that cover our news stands. 
 To sum up, learn to like good literature rather than trash, 
 and get the habit of reading at home. 
 
 An evening at home. Have you ever thought that the 
 whole of society as we know it in this country and in all 
 the civilized world is built upon the family as a center? 
 While this book has treated of the family in its relation to 
 the home, the next book will concern itself with you and 
 your family in relation to your neighbors, or what we call 
 society. But society would be of little value were it not 
 for the training we receive in our home life, for after all, 
 we cannot do as we like in this life. We are not indi- 
 viduals living alone. Every act of ours which is selfish 
 may have as a consequence some influence over another 
 person's life. At home we obey mother and father be- 
 
PUZZLES AND GAMES 383 
 
 cause we love them. We do not think, -perhaps, that the 
 result of our disobedience might bring annoyance or even 
 disgrace upon them or others in the family, but such is 
 usually the case. 
 
 In our ideal home father and mother will join in many 
 of our social activities. An evening gathering around 
 the dining table, or perhaps under the cheerful glow of the 
 lamp on the center table in the living room should be a 
 time when we learn to enjoy each other's society through' 
 conversation, story-telling, and games. Here again habit 
 may play a part. Get the habit of telling the funny 
 things that happen to you during the day at school, or else- 
 where. Let father and mother have a good laugh over 
 some of your pranks or jokes, for it is good hygiene to be 
 cheerful at the table. An interesting habit for the family 
 to form is that of picking over some of the interesting hap- 
 penings told about in the newspaper, or perhaps you have 
 learned some new science facts in school and are reading 
 up for a home project. Why not let father and mother know 
 about it? They are sure to be interested. Sometimes a 
 good charade in which two or three members of the family 
 act out some word by syllables will be good fun and will 
 sharpen your wits. An interesting form of home recreation 
 is to try to act out some little story you have read with 
 brothers and sisters. 
 
 Puzzles and games. Perhaps one of the best ways 
 of spending our recreation time in the evening is in playing 
 games. There are a great many kinds of games, arid this 
 is not the place to tell how to play them, but games of 
 skill are certainly the most fun. Checkers, dominoes, 
 and halma are all good games which train us to think 
 quickly, for they are an interesting kind of mental arith- 
 
384 INDOOR RECREATION 
 
 metic. Crokinole, carroms, ping pong, and table tennis, 
 or games in which marbles are used, and above all, pool 
 and billiards, are interesting games of skill in which the 
 eye and the hand play important parts. Chess is an in- 
 teresting game, and one that requires so much skill that 
 many volumes have been written on how to play it, and 
 it has been called the royal game. Jig-saw puzzles are 
 fun to use when others wish to read and you have to play 
 alone. They are in addition easily made, for any boy 
 can afford a jig-saw, and a jig-saw puzzle can easily be 
 made by pasting a colored picture on a flat board and 
 then cutting the picture up into various patterns. 
 
 Stamp collecting. Another interesting home amuse- 
 ment is that of stamp collecting. Not only is it good 
 fun to have a collection of stamps, but it also may teach 
 us a great deal about the geography, money, and even 
 the history of the different countries of the world. While 
 no one of us can expect to have a very large collection, yet 
 it is quite easy to begin one, and you will soon discover 
 that many grown-ups who have kept their boyhood col- 
 lections are always glad to start the young collector with 
 a present of a few stamps. Wholesale houses which 
 deal with other countries are sure to receive stamps, and 
 usually they can be had for the asking. One need not 
 spend much money in ,this pastime, for there are always 
 many other boys and girls who will collect with you, 
 and who will exchange duplicate stamps. A good way 
 to enjoy stamp collecting is to form a small club which 
 meets around in the homes of different boys and girls. 
 Invite some older person who is interested to come in to 
 your meetings and show you his collection. He will 
 probably be glad to do it, and will tell you many interest- 
 
MECHANICAL TOYS 385 
 
 ing things about stamp collecting and other countries. 
 Sometimes you can have a stamp auction, or an exchange, 
 and thus make an evening pass very pleasantly indeed. 
 Be sure, if you have been given an old collection by some 
 relative or friend collected years ago, that you do not give 
 away or sell cheaply the one or two valuable stamps that 
 may be contained in the collection. The best way to keep 
 a collection is to buy a cheap blank book with places for 
 the stamps and to have a catalog. In this way one can 
 insert the stamps where they belong. 
 
 Mechanical toys. Not all of us can afford some of 
 the expensive mechanical railroad trains, boats, sub- 
 marines, and airplanes that we see nowadays, but almost 
 any boy can make a start by purchasing one of the 
 many erecting devices found in the stores to-day, such 
 as Meccano and Erecto. These are instructive as well 
 as interesting as toys, because we can actually build some 
 of the things that we see planned or read about, and if we 
 cannot afford such toys, a few simple tools and a tool box 
 will give us more real enjoyment than almost anything 
 else, for who does not like to make things. It is for this 
 reason that we played with blocks when we were younger, 
 and boys and girls twelve to fifteen years old like to make 
 things, too. Perhaps it is dolls' dresses, or it may be a 
 model airplane and mechanical engines and boats ; these 
 are interesting because through the use of them we learn 
 something about the real machines we shall meet in later 
 life. Some boys have given to them year after year the 
 various parts of a toy railroad, and in time will have tracks, 
 stations, bridges, and turn tables, block signals, and 
 switches, and models of steam and electric locomotives. 
 These boys will study and understand the working and the 
 
 H.-WHIT. CIV. SCI. IN THE HOME 2$ 
 
3 86 
 
 INDOOR RECREATION 
 
 running of their railway system, and with their friends 
 pass many happy hours u running a railroad." 
 
 Homemade electricity. A great deal of fun may be 
 had from a little further knowledge of electricity which 
 can be made in the home. You have sometimes produced 
 an electric spark when you " scuffed " your feet over the 
 carpet in winter or rubbed the cat's 
 fur the wrong way, or had your hair 
 stand up in an astonishing manner 
 when you brushed it. These are all 
 caused by electricity. Many interest- 
 ing things can be done at home with 
 this electricity if the air is cold and 
 dry. If a hard rubber fountain pen or 
 a rubber comb is rubbed briskly with 
 flannel it will attract small bits of 
 An electrified rod repels the paper or a pith ball supported by a 
 thread. If the ball or the bits of paper 
 become electrified, as they sometimes will after clinging to 
 the rubber for a moment, they will be repelled and fly 
 away from it. 
 
 Experiment. To demonstrate static electricity. 
 
 Materials: Hard rubber rod or stick of sealing wax. Two large rods of 
 solid glass. Fur. Flannel. Silk. Pith ball. 
 
 Method and Results: Electrify the glass (previously warmed a little) by 
 nibbing with silk. Support this on a wire stirrup supported by a 
 thread. Electrify the other glass rod. Bring the charged ends near 
 each other. Result? Rub the hard rubber with fur. Bring the charged 
 end near the charged end of the suspended glass rod. Result ? Hang a 
 pith ball by a thread. Hold an electrified glass on one side of it and an 
 electrified rod of hard rubber on the opposite. Result ? Glass rubbed 
 with silk is positively electrified. Rubber or wax rubbed with flannel 
 or fur is negatively electrified. 
 
 Conclusion: What is the action between electrified bodies? When 
 
ELECTRICAL TOYS 
 
 387 
 
 a neutral body touches an electrified body the charge distributes itself 
 over both bodies, so they are electrified alike. Explain the action of 
 the pith ball when held between the glass and hard rubber. 
 
 Electrical toys. There are several different types of 
 toy electric motors. You will find it interesting to examine 
 some of them to see if you can recognize the different types 
 and find out how they work. A most interesting home 
 project would be to build your own motor. Directions 
 for this can be found in almost any good boy's book of 
 inventions, such as " Home Made Toys for Boys and 
 Girls," by A. N. Hall. There are many electromag- 
 netic devices from which one may get a lot of fun, for ex- 
 ample, an electric hammer can be made by winding a coil 
 of wire around a 
 pencil. Make the 
 coil three inches tall, 
 and wind about ten 
 layers of No. 16 in- 
 sulated wire. Re- 
 move the pencil. 
 Connect one end of 
 the coil to a battery 
 consisting of one or 
 more dry cells. Hold 
 the coil an inch 
 
 above the table. Place a large nail in the hole inside the 
 coil letting the head of the nail rest on the table. Now 
 attach the wire from the other end of the coil to the other 
 pole of the battery, and the nail will rise in the coil. Break 
 the contact, and the nail will fall, striking a strong blow on 
 the table. 
 
 The use of electricity in working a home telephone or 
 
 A toy electric hammer. 
 
3 88 
 
 INDOOR RECREATION 
 
 telegraph outfit will be given when considering communi- 
 cation in the next book. 
 
 SCORE CARD OF MY INDOOR RECREATIONS 
 
 
 Sc 
 
 DRE 
 
 
 Perfect 
 Score 
 
 My 
 
 Score 
 
 Piano or organ 
 
 
 \ 
 
 Playing or singing by members of the family .... 
 Victrola or piano player 
 
 5 
 
 
 Have read at least five books listed in Chapter XXIV, 
 pages 381-382 
 
 5 s 
 
 
 Habitually read at least three standard magazines . . 
 Talk over day's experiences and tell funny stories at meals 
 Group games played in evenings, whole family taking part 
 sometimes 
 
 5 
 5 
 
 r 
 
 
 Skillful in at least two games mentioned in Chapter XXIV 
 Collect stamps, or make collections of other objects; 
 have a hobby 
 
 5 
 
 
 Have made at least one toy mentioned in Chapter XXIV, 
 or have completely dressed a doll, making all clothes 
 myself .... v 
 
 
 
 
 
 
 TOTAL 
 
 CQ 
 
 
 
 
 
 REFERENCE BOOKS 
 
 Beard, American Boy's Handy Book (For projects). Charles Scribner's Sons. 
 Beard, What a Girl Can Make and Do (For projects), pages 227-235. Charles 
 
 Scribner's Sons. 
 Bedell, Practical Electroplating (For projects). Published by author, Springfield, 
 
 Mass. 
 
 Brownell, General Science, Chapter X. P. Blakiston's Son and Company. 
 Butler, Household Physics, Chapter IV (Sound). Whitcomb and Barrows. 
 Carrington, The Boy's Book of Magic. Dodd, Mead and Company. 
 Chemistry Sets, Electrical Sets, Erector Sets. A. C. Gilbert Company, New Haven, 
 
 Connecticut. 
 
 Chemistry Sets, Chemcraft. Porter Chemical Company, Hagerstown, Maryland. 
 Clark, Introduction to General Science, Chapter XXXI. American Book Company. 
 Fall, Science for Beginners, Chapter XXIV. World Book Company. 
 Fisher and Fisk, How to Live, Chapter IV (For teachers). 
 Hall, Home Made Toys for Girls and Boys. Lothrop, Lee and Shepard Company. 
 
REFERENCE BOOKS 389 
 
 Hessler, First Year in Science, Chapters VIII and IX. Benj. Sanborn and Com- 
 pany. 
 
 Hodgdon, General Science, Chapter XII (For projects). Hinds, Hayden, and 
 Eldridge. 
 
 Kelley, Three Hundred Things a Bright Girl Can Do. Dana Estes and Company. 
 
 Lynde, Physics of the Household, Chapters XXVIII, XXIX. The Macmillan Com- 
 pany. 
 
 Meccano Outfits. Meccano Company, Inc., New York. 
 
 Sloane, Electric Toymaking for Amateurs (For home projects). Norman Henley 
 and Company. 
 
 St. John, Real Electric Toy Making for Boys. Thomas St. John. 
 
 Tolman, Hygiene for the Worker, Chapter X. American Book Company. 
 
 Van Buskirk and Smith, The Science of Everyday Life, Project I. Houghton Mifflin 
 Company. 
 
 Williams, How it Works, pages 227-309. Nelson and Company. 
 
 Winslow, Healthy Living, Chapter XVI. C. E. Merrill and Company. 
 
CHAPTER XXV 
 
 OUTDOOR RECREATION 
 
 Problems. i . To learn what games can be played 
 in the home yard. 
 
 2. To find out what science principles underlie our com- 
 mon games and toys. 
 
 3. To see how a lens makes objects appear larger. 
 
 4. To understand how pictures are taken. 
 
 5. To learn the relation of our earth to other heavenly 
 bodies. 
 
 Experiments. i. Demonstrate gyroscopic motion with toy gyroscopic 
 tops. 
 
 2. To show centrifugal force. 
 
 3. To show the processes of printing, developing, and fixing a picture. 
 
 Project I. To PLAN FOR UTILIZING THE PLAYGROUND OF THE 
 HOME LOT. 
 
 1. Determine what space is needed for games which interest 
 you. 
 
 2. Which games require permanent location because of the 
 fixtures, and which allow the ground to be used for other games 
 at times? 
 
 3. What will be the cost of the games? What ones can you 
 make or arrange by yourself? 
 
 Suggested Projects. 
 
 1. MAKE A PINHOLE CAMERA AND TAKE PICTURES WITH IT. 
 
 2. TAKING AND MAKING PICTURES. 
 
 390 
 
THE HOME YARD AND PLAYGROUND 391 
 
 3. TO MAKE A BOX KITE. 
 
 4. TO MAKE A SAILBOAT THAT WILL SAIL INTO THE WIND. 
 
 5. TO MAKE A TOY AIRPLANE. 
 
 6. To MAKE A RUSSIAN NINEPIN SET. 
 
 7. TO LEARN TWENTY CONSTELLATIONS. 
 
 The home yard and playground. Fortunate indeed 
 are the children who have a yard which is their own in 
 which to play. In many cities no such thing is possible, 
 and boys and girls must share with others the public play- 
 grounds where they are found. But every home yard, 
 no matter how tiny, ought to have some space devoted to 
 play. For little children a sand box with its load of clean 
 white sand gives pleasure the day long, and even grown- 
 ups like to build miniature roads or tunnels, and fight battles 
 with toy soldiers, in the make-believe land of the sand box. 
 For older boys and girls, if there is not room for ball, 
 croquet, or tennis, there is at least a place for the game 
 of quoits, tether ball, or Russian ninepins, even in the 
 back yard. Russian ninepins in partic- 
 ular is great fun, and requires a great 
 deal of skill. Tops and marbles have 
 been played by generations of small boys, 
 yet never lose their interest. The top is 
 also of scientific interest to us, for it 
 represents what is known as gyroscopic 
 motion. As the top spins, it resists the 
 force of gravity. As you doubtless 
 know, the instrument called the gyro- The gyroscope. 
 scope is used in many ways, especially 
 on large ships to prevent rolling in storms, in airplanes 
 to keep them upright, and in the new type of marine 
 compass. 
 
392 OUTEOOR RECREATION 
 
 Experiment. To demonstrate gyroscopic motions. 
 
 Materials: A toy gyroscope. 
 
 Method and Results: Set the wheel in motion. How long will it spin 
 with vertical axis? Set in motion and rest one end of axis on the 
 wooden support, with a horizontal axis. If the wheel were not spinning 
 would it stay in that position? Set in motion again. Take hold of 
 one end of axis and quickly change from vertical to horizontal. Com- 
 pare the resistance to this movement when the wheel is revolving to 
 that when the wheel is still. 
 
 Conclusion: What are some laws of gyroscopic action suggested by these 
 experiments? How can the gyroscope act as a stabilizer of ships and 
 airplanes ? 
 
 Darts, slings, and bows and arrows. Any toy that 
 can be made is of more interest than one we buy, and 
 toys which allow us to play in competition with others 
 so that our skill is matched against that of the other 
 fellow, are most interesting of all. Long years ago 
 dwellers on the earth used the sling, the dart, and bow 
 and arrow as a means of getting their food as well as 
 weapons for offense and defense. We all know the story 
 of David and Goliath, and who has not read of the early 
 days in this country when Indians not only shot their food, 
 but also killed their enemies with a bow and arrow ? Very 
 briefly some of the science underlying their use may be 
 mentioned here. For example, in the dart, or in the arrow, 
 why do we have pointed tip, and feathers or pieces of stiff 
 paper at the hind end of the dart or arrow ? The elasticity 
 of wood, metal, and cord is also strongly shown in the case 
 of the bow. In the use of the sling, when we whirl the sling 
 round and round before releasing the missile, we have a good 
 example of centrifugal force. This is the force which would 
 cause each one of us to fly off the surface of the earth as it 
 goes whirling around in space were it not for an opposing 
 force which holds us down, the force we call gravity. 
 
PINWHEELS, KITES, AND SAILBOATS 
 
 393 
 
 Experiment. To show centrifugal force. 
 
 Materials: Pail half full of water. A ball fastened to end of string. 
 
 Method and Results: (a) Swing the pail of water rapidly overhead in a 
 large circle. Is there a time when there is no support under the water? 
 Does it fall out ? (&) Whirl the ball on the string. In what directions 
 may it go if you release it when the string is horizontal? When ver- 
 tical? Make diagrams. 
 
 Conclusion: Centrifugal force is that force causing all bodies moving in 
 a curved path to pull away from that path and to go off in a 
 straight line. The force which pulls towards the center and keeps 
 the whirling body in the curved path is called centripetal force. Ex- 
 plain these terms by reference to the above experiments just performed. 
 
 lifting jo 
 
 Pin wheels, kites, 
 and sailboats. An- 
 other common toy is 
 the pinwheel. Most 
 of us know how 
 to cut the pinwheel, 
 and probably every- 
 body in the class 
 knows that the pin- 
 wheel revolves by 
 the force of the air 
 striking against it, 
 causing motion. The 
 difficult thing in kite 
 flying is to adjust the 
 cord at the point of 
 attachment so that 
 the kite balances and 
 w!ll go up readily. 
 Here again we use 
 the force of moving air, and by fastening the kite at 
 an angle to the direction of the wind, we cause it to rise 
 
 Notice that the wind produces a greater lifting force 
 in A than in B, but that in B the greater part of the 
 force of the wind causes horizontal drifting. This 
 results from the angular adjustment of the kite 
 surface. 
 
394 
 
 OUTDOOR RECREATION 
 
 When sailing into the wind, observe that only a part of the wind force presses on the 
 sail and that only a part of the wind pressure on the sail produces a forward push 
 on the boat. 
 
 higher in the air. A much more efficient kind is the box 
 kite, with its double surface. This, as we can readily see, 
 was the forerunner of the glider, which in turn preceded 
 the airplane of the present day. Sailboats also make 
 
 use of the force of the wind 
 against the sails. An interest- 
 ing project would be to work 
 out the reason why it is pos- 
 sible to make a boat sail 
 against the wind. 
 
 The simple microscope. 
 If you hold a double convex 
 lens over a small object such 
 as an insect or a bug, the 
 object appears larger than it 
 really is. The reading glass 
 is a simple microscope consist- 
 ing of a convex lens. We can 
 even make one ourselves by 
 A simple microscope. blowing a small bulb at the 
 
 \SmoJl insect 
 
THE COMPOUND MICROSCOPE 
 
 395 
 
 end of a piece of glass tubing, filling this bulb with 
 water, and plugging the end. This is a crude micro- 
 scope. 
 
 The compound microscope. The compound microscope 
 is a large, more complex structure. As the diagram shows, 
 it has two sets of lenses, which make the object look larger 
 by a double magnification, first, by a glass nearer the object, 
 
 The compound microscope makes an image A'B' nearer the eye than the object AB 
 and then magnifies it to a still larger image ab. 
 
 or the objective, and later by a glass nearer the eye, or the 
 eyepiece. While not every boy and girl can have a mi- 
 croscope of his own, still in most schools you will find a 
 good compound microscope, and any good-natured science 
 teacher will allow you to work out a project on the con- 
 struction and use of the compound microscope. All 
 sorts of new wonders are opened to those of us who can 
 buy a small microscope for our own, as the beautiful 
 forms of the snow crystals, the life in a drop of water, the 
 structure of an insect's wings. Thousands of wonderful 
 
396 
 
 OUTDOOR RECREATION 
 
 Picture of a bare house. 
 
 objects lie unexplored at our doors, and can only be dis- 
 covered by means of this wonderful instrument. Per- 
 haps some day, when 
 you study biology, you 
 will learn more about it 
 and its uses. 
 
 Photography. Prob- 
 ably one of the most fas- 
 cinating hobbies that 
 any boy or girl can have 
 is that of photography. 
 Not only does it help us 
 to understand the prac- 
 tical use of the camera 
 and its accessories, but 
 it also helps us to un- 
 derstand better the ar- 
 tistic value of objects 
 in nature. The accom- 
 panying pictures of a 
 farmhouse illustrate 
 very well what is meant 
 by composition and bal- 
 ance. A close view 
 (No. i) shows the 
 house without grounds 
 or shrubbery. It is an 
 example of poor com- 
 position although it has 
 good balance of strong 
 light and strong dark. 
 
 viewpoint. 
 
 2. The same house with a setting of grounds 
 and foliage. 
 
A PINHOLE CAMERA 
 
 397 
 
 picture than the first. The house at the left is balanced 
 by the road leading to the right, but as no particular 
 object of interest is shown at the right the picture has 
 poor composition. In the third picture the garden path 
 with its border of shrubs and flowers leads you un- 
 consciously right to the door of the house. There is 
 balance of strong light and strong dark with intermedi- 
 ate tones as well. By making a study of photographs 
 you can easily learn what it is that gives them artistic 
 value. Photography gives us a new interest in that 
 We can picture for all time birds, wild animals, and our 
 
 Explain why the image is inverted. 
 
 favorite haunts in nature. We can make mementoes of 
 good times together with our friends, and what makes 
 a better Christmas present than a card which brings up 
 some pleasant memory of summer doings ? You can use 
 photographs to illustrate your science notebooks instead 
 of drawings, if you so desire, and many a boy and girl 
 have made the cost of the camera several times over by 
 taking photographs and selling them. 
 
 A pinhole camera. The simplest camera is one which 
 any ten-year-old boy or girl can easily make. It is a box 
 of any convenient size, say about five inches square and 
 three inches deep. It must have a cover which slides 
 down over the box for a depth of at least one inch. The 
 
398 OUTDOOR RECREATION 
 
 interior must be painted black, and absolutely light tight-. 
 By following these directions you can make a good camera. 
 
 Cut a hole one half inch in diameter in the middle of one side or end 
 of the box. On the inside of the box paste over the hole a piece of tinfoil. 
 In this tinfoil you will make your pinhole. The success of your picture 
 depends on the care with which you make this hole. The best results are 
 obtained when the diameter of the pinhole is in proportion to the square 
 root of the distance from the pinhole to the plate. 1 Paste cardboard strips 
 on the inside of cover to hold the sensitized plate. 
 
 The exposure, depending on the light, should be from 
 ten to twenty minutes. The picture is made on a glass 
 plate which is held in place by narrow strips of cardboard 
 glued in along the vertical edges of the plate. This plate 
 is to be put into the camera while in a dark room. Of 
 course, the pinhole should be kept covered until you reach 
 the object you wish to photograph and covered again after 
 the picture is taken. 
 
 Camera lenses and their use. There are two types 
 of lenses used, a single lens, found in most cheap cameras, 
 and a lens tube with a double combination of glasses in 
 it which may be of long focus. There is also a wide angle 
 lens of short focus, which is excellent for working indoors. 
 We also have the telephoto lens, which is used for long 
 distance work, and is excellent for photographing birds, 
 and other forms of wild life. 
 
 1 Use the following formula : 
 
 Diameter of pinhole =K^ Distance of plate from pinhole 
 K= .0008 
 
 This diameter may be measured by some machinist or science instructor who has a microm- 
 eter caliper, who can measure a needle of the right diameter, so you can make the hole just 
 the size of the needle. 
 
 Having obtained a needle of the right diameter, do not force it all at once into the tinfoil, 
 but work it slowly, putting pressure first on the one side, and then on the other so as not to 
 stretch the foil when pushing the needle into the hole. When you have made the hole, be 
 sure to smooth off the edges, as a clear picture cannot be made unless you have a clean cut 
 
WHAT IS A NEGATIVE? 
 
 399 
 
 What is a negative ? The picture is taken upon a glass 
 plate or celluloid film covered with a coating of gelatine 
 and silver bromide, or some other silver salt. Light falling 
 on this silver compound causes a change in its composition, 
 
 Which of these two pictures is the negative ? Which the positive ? 
 
 so that when it is put into a developer containing certain 
 chemicals which complete the change and make it perma- 
 nent, we have a negative as a result. This negative gives 
 the light values in black and white, but just the opposite of 
 what they were in the objects photographed and just the op- 
 posite of what we have in a positive, or completed print. A 
 study of the accompanying figure will show this very clearly. 
 
400 OUTDOOR RECREATION 
 
 Experiment. To show the processes of printing, developing, and fixing 
 a picture. 
 
 Materials: Three small glass or enamel trays. One large tray. Printing 
 frame with glass. Film or glass negatives. Azo or Velox paper. De- 
 veloping powders and hypo. A ruby light or dimly lighted room. A 
 strong light for printing. 
 
 Method: Work with some one who is experienced in making pictures at 
 first. Learn from him how to do the various operations. Write 
 a complete report of the processes and the reasons for them as learned 
 from study. Mount a specimen print which you make yourself. 
 
 How to make a picture. In taking a picture, we should 
 bear in mind the following points : (i) We wish to have a 
 pleasing composition. Try to get good balance in your 
 picture. Focus on the principal thing to be photographed. 
 
 (2) Have good light, and if possible, have the light come 
 from behind the camera. Do not have much light and 
 shadow, except in landscapes. Do not take a picture di- 
 rectly in the sun unless you shade the lens of the camera. 
 
 (3) Be sure that the opening in your lens is the right size 
 for the amount of light. This is easily determined by a 
 study of the directions that come with any camera. You 
 will learn to know your own lens and how to use it after 
 you have worked with it for a time. (4) Be sure that you 
 use an unexposed plate or film. Many pictures are spoiled 
 by double exposures. The best way is to write on your 
 plate holder or film each time when you take a picture. 
 (5) Be sure to make an exposure of the proper length. 
 Too long an exposure is as bad as too short an exposure. 
 The camera must not be allowed to move, even in the in- 
 stantaneous exposure. If you take a snapshot be sure 
 that the image of the object you wish to take is in the 
 finder when you snap the shutter. 
 
 Printing. Boys and girls should learn to print their 
 
OTHER USES OF LENSES 401 
 
 own pictures rather than send them to a photographer, 
 for it is easy, and a fascinating pastime. Papers are of two 
 types, those printed by artificial light and those printed 
 by sunlight; the latter require more time and a dark 
 room. Blue printing paper is one form of sun printing 
 paper, which is much cheaper and easier to handle, since 
 we merely have to print from a negative, and then wash 
 in cold water. Chemicals for printing and developing can 
 be found in any good photographic shop and directions for 
 their use in any good manual. 
 
 Enlarging. If you have a particularly good picture, 
 you may wish to enlarge it. This can be done by mak- 
 ing a positive image or picture by allowing rays of light to 
 pass through a negative, then through a lens which is 
 focused on a sheet of sensitive bromide paper. The size 
 of the enlargement will depend on the distance of the lens 
 from the sheet. It is not difficult to enlarge if one has a 
 room which can be darkened, and has a little ingenuity 
 so that he can make a frame to hold the bromide paper. 
 Enlargements are much more artistic because of their 
 softer tone, and make excellent presents. 
 
 Other uses of lenses. We are all familiar with the use 
 of the opera glass and field glass. A good pair of field 
 glasses apparently decreases the distance of the object 
 looked at to one eighth of the real distance. A four-inch 
 telescope may make an object appear one three-hun- 
 dredth of its distance. In the telescope, one lens is used 
 to make an image of the distant object, and the second 
 lens, the eyepiece, is used as a simple microscope which 
 magnifies this image. If you can get the use of a good 
 field glass or small telescope, look at the moon in its differ- 
 ent phases. You will find it a most interesting object for 
 
 H.-WHIT. CIV. SCI. IN THE HOME 26 
 
4O2 
 
 OUTDOOR RECREATION 
 
 observation. An evening with the telescope is an ex- 
 perience that few boys and girls will forget. 
 
 The stars. Even without a telescope, the heavens 
 present a wonderful opportunity for observation to those 
 
 who are interested in the 
 distant parts of our uni- 
 verse. A glance at the 
 sky makes one think he 
 can see myriads of stars, 
 but in reality, on an 
 average one can rarely 
 see more than from two 
 to three thousand stars 
 while standing in one 
 place, but by the use of 
 a large telescope, mil- 
 lions of stars are found. 
 Astronomers tell us that 
 each one of these stars 
 is like our sun, a huge, 
 white-hot ball, and that 
 many of them are very 
 much larger than our 
 
 Yerkes telescope of University of Chicago, one mi 
 
 of the largest in the United States. SUn. They appear Very 
 
 tiny because of their 
 
 great distance. When we realize that the nearest of 
 these stars (Alpha Centauri) is 25,000,000,000,000 miles 
 away, so far that it takes about four and one third 
 years for its light to reach us, we are lost in wonderment. 
 And when we also know that another star (Arcturus) 
 is 950,000,000,000,000 miles' away, and that it takes one 
 hundred sixty years for its light to reach us, we are 
 
THE LARGE DIPPER 
 
 403 
 
 still more amazed. It will help you to get some idea 
 of the velocity of light when you think that as you have 
 taken five steps across an ordinary room, light has traveled 
 a distance equal to about twenty times the circumference 
 of the earth. 
 
 The North Star. One star which has guided many 
 travelers is the North Polar Star (Polaris). When we see 
 it, let us remember that the light which enters our eyes 
 left that star about forty-seven years ago. Since this 
 star is practically in line with the axis of the earth, and 
 all other stars keep the same relative positions, with re- 
 spect to the North Star, there is during the rotation of the 
 earth each twenty-four hours an apparent rotation of all 
 of the other stars in the sky about Polaris as a center. 
 This fact makes it of exceptional value to the traveler. 
 
 The Large Dipper. One of the most conspicuous star 
 groups or constellations is the Large Dipper, or Great 
 Bear, as it is sometimes 
 called. If you are just 
 learning to locate some 
 of the more prominent 
 stars and star groups, 
 the Great Dipper is one 
 you should locate first. 
 From that you can find 
 the North Star (Polaris) 
 and then work out to 
 other groups. If you will 
 examine the diagram, 
 
 you will find that a line drawn from the two stars at the 
 end of the Dipper points directly toward Polaris, hence, 
 they are called the " Pointers." 
 
 Which two stars are the " Pointers"? 
 
404 OUTDOOR RECREATION 
 
 Other star groups. Polaris is the end star in the 
 handle of the Little Dipper, or Small Bear. This can 
 easily be found. Except in the region very near the 
 North Star, some stars will be visible at certain hours 
 of the night and not visible at others. It is an excel- 
 lent plan to get some older person to show you how to 
 use a star map, and then try to see how many new con- 
 stellations you can identify. The " Guide to Nature " 
 and the " Scientific American " have a star map each 
 month, which will show you the tune of evening to look 
 for certain constellations. No more fascinating study can 
 be found than that of elementary astronomy, and learn- 
 ing to know the constellations will give you a start in 
 astronomy. 
 
 Our relation to the stars. You have obtained in your 
 geography some knowledge of the relation of our earth 
 to the other heavenly bodies. You remember that there 
 are eight of these bodies which travel around the sun, 
 the earth being one of the eight. These bodies are called 
 planets. They do not give out light of their own, but 
 they do reflect sunlight, and appear as brilliant stars. 
 They are never visible except in morning or evening, and 
 are therefore called morning stars and evening stars. As 
 we have just learned, they are not true stars, because 
 true stars shine by their own light. The names of these 
 planets, in order according to their nearness to the sun, 
 and the length of their year (or the time to go around the 
 sun) , are shown in the following table : 
 
 Mercury 88 days Jupiter ...... 12 years 
 
 Venus *. 225 " , Saturn 29 " 
 
 Earth 365 ' Uranus 84 
 
 Mars 687 " Neptune 165 " 
 
SHOOTING STARS 405 
 
 Some of these planets, such as the Earth, Jupiter, and 
 Mars, have moons which in turn revolve around them. 
 These simply reflect sunlight, and do not give any light 
 themselves. All of these moons, planets, and the sun to- 
 gether make up a small heavenly group which we call the 
 Solar System. You may think the word small used inad- 
 visedly. It is a large 
 system when com- 
 pared with the size 
 of the earth, but 
 compared with the 
 size of the other 
 systems and the vast 
 expanse of the uni- 
 verse which we look 
 into on a clear night, 
 it is absolutely insig- 
 nificant. It is rea- 
 sonable to believe 
 that each of the mil - 
 
 Relative sizes of planets, sun, and moon. 
 
 lions of stars in the 
 
 sky has its own family of planets and moons, just as our 
 sun has, but since these are so far away and have no light 
 of their own, they are invisible to us. 
 
 Shooting stars. We have all seen the burst of stars 
 which comes from the explosion of a beautiful rocket, 
 and indeed we have sometimes mistaken the light from 
 a small toy balloon for that of a star. It is not strange 
 that some people have been deceived by so-called " shoot- 
 ing stars " and thought that stars were actually falling. 
 Such, however, is not the case. There are throughout 
 the space which surrounds the earth and other planets 
 
406 OUTDOOR RECREATION 
 
 countless numbers of small bodies which are moving at a 
 speed almost one hundred times as swift as that of a rifle 
 bullet, but since there is no air, there is no resistance to 
 these bodies, and they cannot be seen. If any of them 
 
 going at this rate of 
 speed reach the upper 
 air they become hot be- 
 cause of the friction and 
 soon begin to glow so 
 that they appear as ob- 
 jects which are on fire. 
 
 A shooting star. g-^ ^ ^^ attracts 
 
 them, they fall toward it, usually reaching the earth as dust. 
 Sometimes, however, a very large meteor plunges into the 
 earth, and when we dig it up, we find it to be a mass of 
 rock looking not unlike iron. 
 
 Home and community, All through the book we have 
 tried to show how science touches pur everyday life. Only 
 a few of the many home pleasures have been suggested here, 
 for much of your pleasure will be had in the companionship 
 of others. Hiking, fishing, insect collecting, camping, 
 boating, and bathing are all pleasures that others must 
 share with you to be really fun. So we will leave the 
 discussion of these to your project making and to the later 
 treatment of community life. The purpose of the next book 
 will be to show you how intimately science is connected 
 with the lives of those who live together as citizens in the 
 community. It is hoped that the book just being finished 
 may help to make you better and more useful members 
 of your own family. The next book will help to make 
 you more useful and efficient citizens in your own com- 
 munity. 
 
SCORE CARDS 
 
 407 
 
 The last score card. After you have finished this 
 card you are to take all of the completed cards and copy 
 
 SCORE CARD OF OUTDOOR RECREATIONS (FOR GIRLS) 
 
 
 Sot 
 
 )RE 
 
 
 Perfect 
 Score 
 
 My 
 
 Score 
 
 Have set up (5) and can play well (5) one of the games 
 mentioned in Chapter XXV 
 Can play well tennis, croquet, or beanbags 
 Collect flowers and can identify at least 20 varieties . . 
 Collect insects and have specimens of at least six orders . 
 Make photographs (5), develop and print my own pictures 
 M 
 
 IO 
 5 
 
 10 
 
 5 
 
 IO 
 
 
 Belong to Hiking Club or Girl Scouts can walk at least 
 ten miles in a day without feeling tired 
 Can pick out North Star and identify at least three con- 
 stellations 
 
 5 
 5 
 
 
 TOTAL 
 
 ^o 
 
 
 
 
 
 SCORE CARD OF OUTDOOR RECREATIONS (FOR BOYS) 
 
 
 So 
 
 )RE 
 
 
 Perfect 
 Score 
 
 My 
 Score 
 
 Have set out (5) and can play well (5) at least one game 
 mentioned in Chapter XXV 
 
 IO 
 
 
 Have made a kite that will fly and stay up in a moderate 
 wind or 
 Have made a model airplane that will fly at least 100 feet 
 Have made a sailboat that will sail against the wind . 
 Collect insects and have specimens of at least six orders . 
 Make photographs (5), develop and print my own pictures 
 
 (>) 
 
 10 
 
 5 
 5 
 
 IO 
 
 
 Belong to Hiking Club or Boy Scouts, can walk at least 
 twenty miles a day without feeling tired 
 Can pick out North Star and identify at least three con- 
 stellations 
 
 5 
 5 
 
 
 TOTAL 
 
 50 
 
 
 
 
 
408 OUTDOOR RECREATION 
 
 in the column marked " My final real score " in the long 
 preliminary score card, the totals for each of the smaller 
 cards at the ends of certain of the chapters. It will be 
 interesting to compare your final score with the guess 
 you made at the beginning. Were you too high in your 
 first estimate ? And do you really think you have improved 
 conditions somewhat as a result of this study of science? 
 If so, then this book will have accomplished its purpose. 
 
 REFERENCE BOOKS 
 
 Adams, Harper's Outdoor Handy Book, pages 1 20-143 (Kites) . Harper and Brothers. 
 
 Baker, Boy's First and Second Books of Inventions. McClure, Phillips, and Company. 
 
 Beard, Outdoor Handy Book, pages 46-94 (Kites). Charles "Scribner's Sons. 
 
 Book of Knowledge, Project References for all above. 
 
 Bodmer, Book of Wonders. Project references. Presbrey Syndicate. 
 
 Ball, Starland (Last chapter, although entire book is interesting reading). Ginn 
 and Company. 
 
 Campbell, American Girl's Home Book of Work and Play, pages 175-183 (Archery). 
 G. P. Putnam and Sons. 
 
 Cassell, Complete Book of Sports and Pastimes, pages 239-244. Cassell and Com- 
 pany. 
 
 Clark, Introduction to Science, Chapter XXVIII (Photography). American Book 
 Company. 
 
 Downing, A Field and Laboratory Guide in Physical Nature-study. University of 
 Chicago Press. 
 
 Fall, Science for Beginners, Chapter XXVIII. World Book Company. 
 
 Hodgdon, Elementary General Science, Chapter XII (Stars, etc.). Hinds, Hay den, 
 and Eldridge. 
 
 How to Make Good Pictures. Eastman Kodak Company, Rochester, N. Y. 
 
 Lynde, Physics of the Household, Chapter XXVI. The Macmillan Company. 
 
 Miller, Outdoor Sports. Doubleday, Page and Company. 
 
 Miller, Outdoor Work. Doubleday, Page and Company. 
 
 Smith and Jewett, Introduction to Science. The Macmillan Company. 
 
 Thompson, Boy's Book of Sports, pages 177-196. The Century Company. 
 
INDEX 
 
 NOTE. Numbers in heavy-faced type refer to pages containing illustrations as well as 
 descriptive text. 
 
 Abdomen of insect, 319 
 Absorbing organs, in animals, 100 
 
 of plants, 304 
 Accommodation, 259 
 
 relation to focusing, 259 
 Acids, test for, 234 
 Adenoids, 70 
 Aerobic, 153 
 Air, in lungs, 63 
 
 impurities in, 46 
 
 ocean of, 40 
 
 pressure, 59 
 
 principal gases in, 42 
 
 properties of, 42 
 
 pure, 27 
 
 reality of, 41 
 
 relation to health, 65, 163 
 
 relation to light, 184 
 
 relation to soil, 301 
 
 supply, regulation of, 193 
 
 weight of, 59 
 
 Air passages, diseases of, 70 
 Ammeter, 364 
 Ampere, 364 
 Anaerobic, 153 
 Anopheles, 14, 135 
 Ants, 138 
 
 relation to food, 139 
 Arsenate of lead, 326 
 Arteries, 145 
 Astigmatism, 260 
 
 Bacteria, 19, 59 
 aerobic, 153 
 anaerobic, 153 
 bacillus, 153 
 coccus, 153 
 conditions favorable and unfavoiable, 
 
 119 
 culture medium, 67 
 
 Bacteria Continued 
 
 denitrifying, 316 
 
 growth of, 119, 159 
 
 relation to diseases, 160 
 
 relation to food, 120 
 
 relation to soil, 316 
 
 types of, 1 60 
 Bathroom, modern, 148, 281 
 
 flush tank, 150 
 Bedbugs, 138 
 
 Bedroom, ideal, ventilation of, 277 
 Bees and wasps (Hymenoptera), descrip- 
 tion of, 323 
 
 Beetles (Coleoptsra), description of, 323 
 Bell, electric, 351 
 Bifocal lens, 261 
 Birds, 328, 329 
 
 Bleaching, relation to clothes, 233 
 Blood vessel, 145, 220 
 Body, compared to engine, 91 
 
 composition of, 92 
 
 poisons, 1 66 
 
 relation to clothing, 220 
 
 relation to food, 92, 99 
 
 relation to heat, 221 
 Bordeaux mixture, 326 
 Bread making, 118 
 
 yeasts in, 117 
 Breathing, 60 
 
 necessity for, 63 
 
 process of, 61 
 Brick, making of, 273 
 Bronchial tubes,' 60 
 Bugs (Hemiptera), description of, 323 
 Burning test, 228 
 Butterfly or moth, adult or imago, 320 
 
 eggs, 319 
 
 larva or caterpillar, 320 
 
 life history of, 319 
 
 pupa, 320 
 
 409 
 
4io 
 
 INDEX 
 
 Calorie, 99 
 
 Camera, 255, 397 
 
 Candle, relation to air, 44 
 
 Canning foods, 124 
 
 Capillaries, 146 
 
 Capillarity, experiment in, gravel, sand, 
 
 clay, and loam, 300 
 Carbohydrates, 94 
 
 test for, 95 
 
 Carbon, 93, 176, 179, 361 
 Carbon dioxide, 43 
 
 fire extinguisher, 215 
 Carbon tetrachloride extinguishers, rela- 
 tion to fire, 213 
 Carelessness, 31 
 Carpet beetles, 139 
 
 destruction of, 139 
 Caterpillar, 320 
 Caves, formation of, 86 
 Cellar, 282 
 
 relation to heat, 282 
 Cells, 48 
 
 electric, dry, 361 
 joining of, 365 
 life of, 366 
 to make, 362 
 wet, 361 
 
 in body, 47 
 
 respiration, 62 
 
 Centrifugal force, demonstration of, 395 
 Cesspool, 153 
 Chemical elements, 93 
 Chemical extinguishers, types, 213 
 
 section of, 215 
 Choroid, 258 
 Chrysalis, 320 
 Ciliary, 259 
 
 Cinders, removal of, 265 
 Cisterns, 77 
 Cleanliness, habits of, 169 
 
 relation to clothes, 232 
 
 relation to home life, 31 
 Clothing, 220 
 
 attacked by insect, 139 
 
 care of, 232 
 
 frauds in, 231 
 
 origin of, 225 
 
 relation to cold, 220 
 
 use of, 223 
 
 Coal beds in the earth, 176 
 Coal stove, 190 
 Cockroaches, 138 
 
 Cocoon, 320 
 
 Cold, relation to clothing, 220 
 
 Cold frame, 309 
 
 Cold storage warehouse, 121 
 
 Color, 256 
 
 in the home, 276 
 
 nature of, 256 
 Color blindness, 264 
 Combustion, 46 
 
 Commercial motors, in the home, 35 2 
 Concrete skyscraper, 272 
 Conduction, 186 
 Convection currents, 184, 185 
 
 caused by hot stove, 191 
 Cooking, methods of, in, 112 
 
 relation to food, 109 
 
 use of heat in, 198 
 Cootie, 139 
 Corn smut, 317 
 Cotton, description of, 227 
 
 relation to body, 227 
 Cotton plant, 227 
 Crop rotation, reasons for, 305 
 Crowding, menace to health, 30 
 Culex, 135 
 Culture medium, 67 
 Current, electric, 348 
 
 sources of, 351 
 Currents, convection, 185, 190, 191, 192 
 
 direction of air, 65 
 
 electric wire resistance, 363 
 
 Decay, 119, 165 
 
 cause of, 119 
 
 of teeth, 165 
 Diaphragm, 60 
 
 D ets, differences in, reasons for, 104 
 Digestion, 99, 100 
 Digestive tract, 100 
 
 nature of, 101 
 Diseases, body defenses against, 163 
 
 of air passages, 70 
 Disinfectants, use of, 162 
 Drainage system, relation to water sup- 
 ply, 79 
 
 pipes, 151 
 
 relation to home, 28, 50 
 Drinking cup, hygienic, 167 
 Drugs, abuse of, 171 
 
 use of, 170 
 Dust, danger of, 66 
 
 proper removal of, 68 
 
INDEX 
 
 411 
 
 Ear, 377 
 
 Edison, Thomas, 32, 33 
 
 Electric measuring instruments 
 
 ammeter, 364 
 
 voltmeter, 364 
 
 wattmeter, 368 
 Electric units 
 
 ampere, 364 
 
 kilowatt hour, 368 
 
 volt, 364 
 
 watt-hour, 369 
 Electricity, circuit, 366 
 
 control of, 246 
 
 electric bell, 349 
 
 electric cells, properties of, 361 * 
 
 electric currents, 348, 360, 364 
 
 electric heating devices, 354 
 
 electric iron, 356 
 
 electric toaster, 356 
 
 electrical toys, 387 
 
 electromagnets, 345, 349 
 
 in the home, 345, 360 
 
 measuring of, 364, 368 
 
 pressure of, 363 
 
 production of, 362 
 
 relation to lighting, 246 
 
 resistance to, 362 
 
 static, 386 
 Electromagnet, description of, 345 
 
 how to make, 349 
 Elytra, 323 
 Emulsion, 234 
 Energy, 52, 338 
 
 electricity and heat, 355 
 
 from food, 94 
 
 sun source of, 52 
 Environment, 40 
 
 scoring of, 55 
 
 Enzymes, relation to digestion, 102 
 Exercise, 33, 34 
 
 Expiration, relation to breathing, 62 
 Extinguisher, fire, 213, 215 
 Extinguishing, burning fat, 214 
 
 gasoline, 214 
 Eyes, adaptation, 260, 264 
 
 care of, 264 
 
 change in the pupil, 259 
 
 control of, 260 
 
 defects of, 260 
 
 importance of, 31, 253 
 
 section of, 258 
 strain, 26 
 
 Eyes Continued 
 structure of, 257 
 testing of, 262 
 
 Fabric, effect of chemical reagents, 
 
 231 
 
 Fainting, 73 
 Farsightedness, 261 
 Fats, 94 
 
 tests for, 96 
 Faucets, leaky, 85 
 
 types of, 84 
 Feet, care of, 224 
 Fireless cooker, 112 
 Fire, 211 
 
 chemical extinguishers, 213, 215 
 
 dangers of, 206, 210 
 
 extinguishing, 212 
 
 flames for light, 209 
 
 losses, 207 
 
 prevention of, 205 
 
 regulation of, 190 
 
 smothering, 212 
 
 sources of, 208 
 Fire-making, 183 
 Flax, 228 
 Fleas, 137 
 Flush tank, 150 
 
 how it works, 151 
 Fly, house (Diptera) 
 
 extermination of, 134 
 
 life cycle of, 134 
 
 relation to home, 132 
 
 trap, 135 
 Focusing, 259 
 Food chart, dietary, 106 
 Foods, 53 
 
 affected by bacteria, 120 
 
 animal origin, 98 
 
 bulky foods, 164 
 
 carbon and water in, 93 
 
 classification of, no 
 
 economy of, 105 
 
 flavors of, 127 
 
 indigestible, 164 
 
 plant origin, 97 
 
 preparation of, 99 
 
 preservation of, 121 
 
 relation to health, 99, 165 
 
 simple foods, 164 
 
 spoiling of, 116 
 Footpound, 339 
 
412 
 
 INDEX 
 
 Force, 333, 335 
 
 centrifugal, 392 
 
 centripetal, 393 
 Friction, 337 
 
 rolling, 337 
 
 sliding, 337 
 Fuel, burning elements of, 179 
 
 economy of, 177 
 
 heating value, 178 
 
 kinds of, 176, 202 
 
 sources of, 176 
 Fulcrum, 334, 335 
 Fungi, 317 
 
 types of harmful, 317, 318, 320 
 Fuses, 368 
 
 Games, 383, 393 
 Gardening, cultivation, 301 
 
 indoor, 292 
 
 science in, 298 
 
 spraying, 327 
 
 value of birds, 328 
 Gas, advantage of mantle, 245 
 
 desirability of, 245 
 
 fishtail flame, 245 
 
 flame, luminous and non-luminous, 199 
 
 in the home, 244 
 
 meter, 201 
 
 range, 199 
 
 Gasoline, treacherous cause of fire, 211 
 Germ dangers, 158 
 Germs, see Bacteria 
 
 growth of, 159 
 Glass, importance of, 270 
 Granite quarry, 270 
 Graph, showing temperature, 22 
 Grasshoppers (Orthoptera), 323 
 Grease, removal of, 235 
 Grounds, planning of, 286 
 Gyroscope, 391, 392 
 
 Hay fever, 69 
 
 Head, related to insect, 319 
 
 Health, body poisons, 166 
 
 exercise and, 167 
 
 rest and, 169 
 
 rules of, 34, 172 
 Hearing, 376 
 Heart, 145 
 Heat, 51 
 
 distributing, 185 
 
 from electricity, 247, 355 
 
 Heat Continued 
 
 heat travels, 186 
 
 in homes, 196 
 
 loss from body, 221 
 
 relation to energy, 52 
 
 steam, 196 
 
 sun, source of, 51 
 Hemiptcra, 323 
 Home, 270 
 
 beginnings of, 25 
 
 choosing 27, 28, 274 
 
 duties of children at, 33, 168 
 
 efficiency in, 32 
 
 electricity in, 360 
 
 environment of, 55 
 
 grounds of, 287 
 
 grounds surrounding, 286 
 
 heating of, 189 
 
 ideal, 27 
 
 ideal location and drainage, 28 
 
 ideal score card, 36, 37 
 
 motors in, 352 
 
 recreation in, 33 
 
 regulation of light in, 241, 243 
 
 removal of wastes, 146 
 
 requirements, 27 
 
 scoring of, 35 
 
 suburban, 25 
 
 use of color in, 277 
 
 water supply in, 80 
 Hot-air furnace, 191, 192 
 
 advantages and disadvantages 
 
 193 
 
 Hotbed, use of, 310 
 Hot- water heating system, 194 
 
 advantages and disadvantages 
 
 iQS 
 
 how a room is warmed, 194 
 
 principle of, 193 
 Hot water, supply of, 200 
 House, floors of a well-planned, 275 
 Humus, 50 
 Hydrogen, 93 
 
 burning, 180 
 
 Iceless refrigerator, 124 
 Ichneumon flies, 327 
 Imago, 320 
 
 relation to butterfly, 320 
 Immunity, 163 
 
 antitoxin treatment, 163 
 Impervious layer, 77 
 
 of 
 
 of, 
 
INDEX 
 
 413 
 
 Infection, 161 
 
 how it takes place, 161 
 Inoculation, relation to soil, 317 
 Insect, 318 
 
 abdomen, 319 
 
 classification of, 140 
 
 collecting, 322 
 
 damage to clothing, 139 
 
 description of, 319 
 
 friends, 327 
 
 garden friends, 328 
 
 harmful to fruit trees, 327 
 
 household pests, 138, 139 
 
 how to fight, 138, 139, 325 
 
 injurious, 329 
 
 life history of, 321 
 
 recognition of, 322 
 Inspiration, in relation to breathing, 
 
 62 
 
 Insulating material, 360 
 Intestines, 100 
 Iris, 258 
 
 Kerosene emulsion, 326 
 
 light, 244 
 
 Kilowatt hours, 369 
 Kindling temperature, 181 
 Kitchen, a model, 126 
 
 cleanliness in, 127 
 
 ideal, 280 
 
 Labor-saving devices, 332 
 
 Lanz, David, 140 
 
 Larva, 320 
 
 Laveran, 13 
 
 Leaf, food manufactory, 308, 309 
 
 Legumes, 304 
 
 related plants, 304 
 Lenses, 254 
 
 focal lengths, 254 
 
 use in focusing, 255 
 
 uses of, 256, 401 
 Lever, 333, 335 
 
 principle of, 334 
 Lice, 137 
 Light, 51, 238 
 
 artificial, 243 
 
 home use, 241 
 
 necessity for life, 51 
 
 relation to man, 239 
 
 sources of, 238 
 
 sunlight, 242 
 
 Light Continued 
 
 surfaces diffusing, 241 
 
 tungsten, 248 
 Lighting, artificial, 244 
 
 candle, 244 
 
 electricity, 247 
 
 gas, 244 
 
 illustration of, 249 
 
 kerosene, 244 
 
 methods of, 250 
 Lime-sulphur fungicide, 326 
 Lime-sulphur spray, 326 
 Lime-paris green, 326 
 Linen, description of, 228 
 Lists, garden vegetables, insects, and 
 
 prevention and cure, 325 
 Living room, ideal, 279 
 Lungs, capacity of, 63, 64 
 
 give off wastes, 63, 64 
 
 relation to breathing, 60 
 
 Machines, in the home, 332 
 
 law of, 338 
 
 mechanical advantage, 335 
 
 sewing, 340 
 
 washing, 342 
 Magnets, electromagnets, 345, 349 
 
 laws of magnetic poles, 346 
 
 magnetic field, 347 
 
 properties of, 346, 348 
 Magnetism, law of, 347 
 
 magnetize iron bar, 348 
 Malaria, 13 
 
 Manganese dioxide, 361 
 Manson and Warren, 16 
 Map showing tuberculosis districts, 30 
 Marketing, 108 
 Matches, 209 
 
 relation to fires, 183 
 Mechanical advantage, 335 
 Mechanical toys, 385 
 Menu, how to select, 108 
 
 proper, 109 
 
 Metamorphosis, of butterfly, 320 
 Meter, gas, 201 
 Microscope, 394 
 
 Mind, influence on digestion, 104 
 Molds, fruiting bodies, 119 
 
 in the home, 118 
 
 spores, 119 
 Mosquitoes, 14, 135 
 
 anopheles, 14, 135 
 
INDEX 
 
 Mosquitoes Continued 
 
 life history of, 14, 15, 136 
 
 relation to malaria, 14 
 
 relation to yellow fever, 137 
 Moths, life history of, 319 
 
 relation to clothes, 139 
 Musical scale, 378 
 Music and noise, 378 
 
 Nearsightedness, 260 
 Neutralization, 234 
 Nitrates, relation to soil, 305 
 
 soluble, 315 
 Nitrogen, 43, 93 
 
 cycle of, 316 
 
 related to soil, 304 
 Nodules, 304 
 
 related to plants, 305 
 Noise, 378 
 Nutrients, classification of, 94 
 
 function of, 94 
 
 test for, 95, 96 
 
 Oil fields, 177 
 Opaque, 240 
 Oxidation, 47 
 
 relation to oxygen, 46 
 Oxygen, 93, 145 
 
 relation to air, 42 
 
 Pasteur, Louis, 126 
 Pasteurization, 126 
 
 pasteurizing apparatus, 125 
 Peristalsis, 103 
 Pests, 329 
 
 damage done by, 131 
 
 life history of the fly, 133 
 
 relation to home, 141, 142, 143 
 Phonograph, 380 
 Photography, 396 
 Picture, enlarging, 401 
 
 making, 400 
 
 printing of, 400 
 Pinhole camera, 397 
 Plant enemies, 327 
 Planting, 293 
 
 city gardening, 293 
 
 crop rotation, 305 
 
 for pleasure, 293 
 
 for profit, 293 
 
 relation to soil, 303 
 
 seed table for home gardening, 311 
 
 Plants, changed into living material, 306 
 
 friends, 328, 329 
 
 pests, 314, 317 
 
 relation to soil, 303, 305 
 
 root-hairs, 304 
 
 starch-making power, 306 
 
 test for food, 305 
 Plate culture, 67 
 Pneumatic tank system, 82, 83 
 Polyps, 70 
 
 Preservatives, in relation to foods, 121 
 Prism, 257 
 Projects, list of, 20 
 Prolegs, relation to butterfly, 320 
 Protein, 94 
 
 food rich in, 95 
 Pumps, force, 82 
 
 lift, 81 
 Pupa, 320 
 Pupil, 258 
 Puzzles, 383 
 
 Radiation, 185 
 Rain water, 76 
 Rats, 140 
 
 relation to man, 140 
 Reading, good, 381 
 Recreation, indoor, 372 
 
 outdoor, 294, 391 
 
 relation to home life, 372 
 Reflection, 240 
 Refrigerator, 122 
 
 construction of, 123 
 
 iceless, 124 
 
 use of, 123 
 
 value of, 122 
 
 Resistance in wire to electricity, 363 
 Respiration, artificial, 71 
 
 of cells, 62 
 
 organs of, 69 
 
 products of, 63 
 
 relations to activity, 62 
 Retina, 258 
 Rooms, bedroom, 278 
 
 dining room, 279 
 
 living room, 279 
 Ross, 14 
 
 Sal ammoniac, 361 
 Sanitation, bathroom, 148 
 
 flush tank, 148 
 
 garbage pails, 153 
 
INDEX 
 
 415 
 
 Sanitation Continued 
 
 plumbing, 147 
 
 Save life, artificial respiration, 71 
 Science, in the garden, 298 
 
 method of, n 
 
 recent progress in, 1 2 
 
 relation to discovery of malaria, 13 
 
 study of, 1 6 
 
 use in daily life, 13, 17 
 
 use in home work, 18 
 
 use in straight thinking, 17 
 Sclerotic, 258 
 Semicircular canals, 377 
 Septic tank, 153, 154 
 Sewage, disposal of, 152 
 Shears, 333 
 Sheep, 226 
 Short circuit, danger, 367 
 
 description of, 366 
 Silk, description of, 229 
 
 relation to heat, 230 
 Siphon, method of working, 149 
 Skin, 220 
 
 bathing of, 222 
 
 section through, 220 
 Smothering, 212 
 Snakes, 330 
 Soap, use of, 233 
 
 washing powders, 234 
 Soil, air in, 301 
 
 composition of, 49, 299 
 
 effect of cultivation, 301, 302 
 
 formation of organic, 50 
 
 harrowed and packed, 302 
 
 inorganic, 302 
 
 nitrogen from, 304 
 
 relation to home, 50 
 
 relation to planting, 49 
 
 water in, 300 
 Solution, meaning of, 86 
 
 soluble, 86 
 Sound, 373 
 
 due to vibration, 373 
 Spectrum, 258 
 Speech, 375 
 Speed, change of, 340 
 Spiracles, 320 
 
 Spontaneous combustion, 211 
 Spots and stains, removal, 235 
 Springs and wells, 77 
 
 relation to underground water, 77 
 
 safe and deadly, 78 
 
 Stamp collecting, 384 
 Stars, 402 
 
 groups of, 404 
 
 Large Dipper, 403 
 
 North Star, 403 
 
 our relation to, 404 
 
 shooting, 405 
 Steam heat, 195 
 
 advantages of, 197 
 
 description of, 196 
 
 disadvantages of, 197 
 
 heat stored in steam, 196 
 
 protection of loss of heat, 197 
 Stone, 270 
 
 artificial, 271 
 
 granite quarry, 270 
 
 life of building, 271 
 Stoves, coal, description of, 190 
 Stringed instruments, 379 
 Sun, position of, 52 
 Sunlight, absorption of, 242 
 
 Teeth, 102, 165 
 
 care of, 165 
 
 decay, 165 
 
 uses of, 102 
 Telephone, 352 
 Temperature, 181 
 
 kindling, 181 
 
 measurement of, 22, 182 
 
 regulation of, 220 
 
 relation to body, 183 
 Tepee, 26 
 Tests, astigmatism, 262 
 
 for farsightedness, 262 
 
 for nearsightedness, 262 
 Textile fibers, 231 
 Thermometer, clinical, 182 
 
 house, 182 
 Thermos bottle, 125 
 Thorax, 319 
 
 related to insect, 319 
 Toxins, 163 
 Tracheae, 323 
 Transformer, 351 
 Translucent, 240 
 Transparent, 239 
 
 transparency, experiment, 240 
 Traps, 152 
 Trees, arrangement of, 288 
 
 relation to home, 289 
 
 use of, 289 
 
416 
 
 INDEX 
 
 Tungsten light, 248 
 advantage of, 248 
 
 Underclothes, 223 
 kinds, 222 
 mesh, 223 
 uses, 223 
 
 Vaccination, 163 
 
 Vacuum sweeper and cleaner, 353 
 
 system of, 354 
 Ventilation, need of, 65 
 
 principles involved, 66 
 
 relation to health, 65 
 Vermiform appendix, 100 
 Villi, 100 
 Vitamines, 107 
 Vitreous humor, 258 
 Vocal cords, 375 
 Voice, 375 
 
 control, 376 
 Volt, 364 
 Voltage, 363 
 Voltmeter, 364 
 
 Wastes or poisons, 144, 145 
 body poisons, 166 
 removal from body, 145 
 removal from home, 146 
 
 Water, 47 
 
 composition of, 75, 180 
 
 Water Continued 
 
 cycle of, 76 
 
 hard, 86, 87 
 
 impure, 78 
 
 lifted by air pressure, 80 
 
 pure, 27, 74 
 
 purification, 87 
 
 rain, 76 
 
 relation to body, 48 
 
 relation to home, 79 
 
 relation to soil, 300 
 
 soft, 86, 87 
 Water seal, 151, 152 
 Weighing, 336 
 Weight, 333, 335 
 Wells, 77 
 
 artesian, 77 
 
 deadly, 79 
 
 pollution of, 152 
 
 safe, 79 
 Windpipe, 60 
 Wood, cross section of, 268 
 
 relation of markings, 270 
 Wool, description of, 226 
 
 relation to body, 227 
 Work, unit of, 339 
 
 Yeasts, 117 
 
 used in bread making, 117 
 
 Zinc rod, 361 
 
UNIVERSITY OF CALIFORNIA LIBRARY