A WONDERFUL ENGINE
We all have seen a steam engine, have we not? There are engines that pull trains on the railroad, and there are engines that make factories, gins, and saw-mills work. Then there are engines that run great ships on the water. How many know what must be done to one of these engines before it can do all this work? "It must have coal, or wood, or gasoline put into it." That is right.
Now this coal or wood or gasoline, when it is used in an engine to make it work, is called fuel. Would we put rotten or green wood into the engine? No. We must always put in the kind of thing that will burn best, and make the most heat and do the most work.
Let us see how this wood or coal we call fuel makes the engine work. First, we must burn the fuel. Second, when the fuel burns, it heats the water in the boiler. Third, the water changes into steam, and this steam gives the engine the power to work.
Now we see how an engine is made to move and do work, such as hauling great trains of cars, and pulling great ships across the wide ocean. But we must remember that the engine will not do this work unless there is a man near-by to put the fuel into the engine.
I want to tell you of another engine that is very like the steam engine. It too must have fuel before it can run or work. It is unlike the steam engine in as much as it grows all the time, and it does not need to have an extra man to put the fuel into it. You must think of your body as an engine and remember that it needs fuel to run it. The fuel that makes the body-engine move and work is the food you eat.
You have learned that you must put into the steam engine the fuel that will burn best and make the most heat and work. The same thing is true of your body-engine. You must put in the fuel that will best make heat and the power to work. Have you sometimes eaten something which made you sick? It must have been that that was the wrong kind of fuel for the little body-engine. This is the reason our mothers are so very careful in preparing our food. They want the little engines to have the right kind of fuel so that they will not run off the track.
Now what fuel must you use in your body-engine? In the first place you must put in fuel that will make the engine grow so that it can do a great deal of work. This fuel you get when you eat lean meat, eggs, milk, and many other things.
If you want your engine to keep warm, you must use fuel that will make heat. You get this fuel by eating plenty of fats, such as nice butter and some sweet things. Potatoes, rice and syrup help to run your engine.
You need some fuel that will make you plump and round and healthy looking, so you must put into your engine fruits, nuts, a little candy, and a lot of vegetables. You need to eat things that have color, such as: tomatoes, lettuce, greens, and beets,—not because they look pretty, but because they have iron in them and help to make your engine strong.
You must remember that you eat food for three reasons: to make you grow, keep warm, and able to work. You must be careful that you do not eat too much of any one kind of food, but remember to eat a little of many kinds. Your engine can use only a little of each at one time.
Wood is chopped into short pieces, and coal is broken up before it will do good work in the engine, so the fuel must be prepared before it will suit your engine. It must be well cooked and then chewed thoroughly before it will do its best work in your body-engine. You should be careful not to swallow any food until it has been chewed as fine as it can be.
If you put into your engine the right amount of food, and the right kind of well-prepared food, you will have an engine more wonderful than any steam engine that ever pulled a train, or carried a big ship across the wide ocean.
The engineer sees that his engine is kept clean and bright, in order that it may run smoothly. Since you are the engineer of your body-engine, you must keep it neat and clean that it may work well.
QUESTIONS
1. What is it that causes the big steam engine to do its work, draw long trains, or big ships, or turn great factory wheels?
2. What must happen to this fuel—wood, coal, or gasoline—before it can make the engine do its work?
3. Did you ever wonder why it is that your body is always warm? It is very much like the engine.
4. What do you call this fuel that your body-engine uses? Just as the fuel for the steam engine must be burned if it is to make heat, even so must the food be burned in your body if it is to keep it warm and able to work. Of course the food in your body does not burn exactly as the wood and coal burn in the steam engine. It burns much more slowly—so slowly that you would not know that it burns at all if it were not that it always keeps your body warm.
Just as the steam engine needs the fuel if it is to do its work well, your body needs the best of food if it is to be healthy and do the best work. You have learned that all foods do not serve the same purpose equally well. For instance, some foods such as lean meat, eggs, and milk build up more muscle than other foods do; while others, such as fats, syrup, sugar and potatoes, give more heat than other foods.
5. What do all colored vegetables contain?
6. What kinds of foods do people living in the very cold climates need a great deal of?
7. What kinds of foods do people living in very warm climates need a great deal of?