What is a magnet? What are the poles of a magnet? What is a temporary magnet? - What is a magnetic field ? First Things about Electricity Electric magic. Are all electric charges alike? – How does a lightning rod protect a house ? — Where does an electric cur- rent come from? Can we make a magnet from a current ? What is an electromagnet ? How do we ring an electric bell? — How can a telegraph wire carry a message ? How can Why can we see objects ? How does sunlight travel ? How does a mirror change light? - Why does an object have Can light be turned out of its course ? — How does a burning glass work? How does light form an image ? — How does a camera work? — What is the color of sunlight? — What is a rainbow? Why does an object have color? How do we get sunlight into the house? How have men lighted their houses at night? - How do kerosene lamps work? How do we get light from gas? — How does a fuse box pro- What causes a sound? How do we hear? What causes an echo? What is the difference between noise and tone? How does man lighten his work ? What advantage do we get from machines ? - - Is a teeter a machine ? How many ma- How does a sailboat use the wind? — Why do kites fly? Why do airplanes rise? . Why do windmills turn? How has work? How is cream separated from milk? - How does a - How do plants live? What parts has a plant? How do seeds begin growing ? · What are leaves like? What are - - How does man make use of plants ? - Loes man eat grass? What grasses do we use? How do corn and rice grow? How are trees our friends? How does a tree get its shape? What is the inside of a tree like? What are sapwood and enemies of our trees? What is a weed ? How can we plant - How many kinds of animals are there? Have animals helped, or hindered, man's progress ? - What are man's beasts - What is the plan of the body ? What are living cells like? What are cells made of ? What are bones like? How do bones grow? — Why do we have joints ? What is the skeleton like? – How do our muscles work? — What is the use of ten- What organs digest our food ? - How does the mouth help in digestion? What is the work of teeth? - How do we What is the use of blood ? — What are red corpuscles for? What is the work of white corpuscles? — How is bleeding stopped? — How does the heart pump the blood ? — How do arteries differ from veins ? Does an artery bleed like a vein ? What are capillaries ? How does food get to the cells ? How does the blood get rid of cell wastes ? — Exercises and sum- How do animals breathe? How does inhaled air get to the lungs? — What are the lungs like? — What is the voice? -- Do the organs of respiration need care? What is the structure of the skin? How do hair and nails grow? What is the work of the skin? — What is the value of bathing? - Exercises and How can our organs work together? - What is the work of the brain? What is the brain like? What is the spinal What has science taught us? How can science help a com- 517 523 |
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