II. An Early Romp.

  1. Which makes you more tired, to walk slowly, just “lagging along,” for about twenty minutes, or to walk briskly for the same time? Why?
  2. How do you make your muscles strong? What is your heart made of? How can you make your heart strong?
  3. Why do you need a heart?
  4. What is your pulse? Where can you easily feel a pulse? Count the pulse of someone else for half a minute by a watch. Do this accurately. How many beats would there be in a minute? Try this with different classmates.
  5. What do we call the tubes through which the blood flows away from the heart? The tubes through which it flows back to the heart?
  6. What is happening to the blood on its “round trip”? Where does it get the liquid food that it delivers to the muscles? Why must the blood be carried away from the muscles?

III. Fresh Air—Why We Need It.

  1. If you were asked how we can tell that air is everywhere, what could you say?
  2. What do we call a thin light substance like air?
  3. What proof have we that the body needs it? How does it get around to the different parts of the body?
  4. What is the body—its muscle, bone, skin, and all—made up of? How do these cells use the air? Why do you need to breathe so often?
  5. In the candle experiment, is all the air under the glass used up? What is used up? How can we compare a person in a closed room to the burning candle under the glass?
  6. What is the gas that we breathe out?
  7. In what three ways does the body “clean house”?

IV. Fresh Air—How We Breathe It.

  1. Where are your lungs?
  2. Draw a picture of the ribs.
  3. In what position are they when the lungs are filled with air? In what position is the diaphragm then?
  4. What are the lungs giving off in the breath besides carbon dioxid? How can you prove this?
  5. How can you prove that the gas in your breath is not like the gas in the fresh air around you?
  6. Why does a room with people in it grow very warm if the doors and windows are kept closed?
  7. How does Nature keep the outdoor air clean? What makes the winds?
  8. Are you careful to keep your breath as clean as possible? How? How do you help keep the air in your house clean?

In School

I. Bringing the Fresh Air In.

  1. What do we mean by fresh air? Why must the air we breathe have oxygen in it?
  2. Is the air in the room now the best you can have in it? How is the air moving?
  3. Is there always the same amount of air in the room? Then, if there is more fresh air, there must be—bad air? If there is less fresh air, there must be—bad air? What is the quickest way to let the bad air out and the fresh air in? Why are you given recess?
  4. What is a draft? Are drafts dangerous?
  5. Will night air hurt you? What air can you have in the house at night except night air?

II. Hearing and Listening.