CHAPTER I.

The house we live in.

1.  Object of this Book.—­The object of this book is to tell the little boys and girls who read it about a wonderful house.  You have all seen some very beautiful houses.  Perhaps they were made of brick or stone, with fine porches, having around them tall shade trees, smooth lawns, pretty flower-beds, walks, and sparkling fountains.

2. Perhaps some of you live in such a house, or have visited some friend who does.  If so, you know that the inside of the house is even more beautiful than the outside.  There are elegant chairs and sofas in the rooms, rich carpets and rugs on the floors, fine mirrors and beautiful pictures upon the walls—­everything one could wish to have in a house.  Do you not think such a house a nice one to live in?

3.  The Body is Like a House.—­Each of us has a house of his own which is far more wonderful and more curious than the grandest palace ever built.  It is not a very large house.  It has just room enough in it for one person.  This house, which belongs to each one of us, is called the body.

4.  What is a Machine?—­Do you know what a machine is?  Men make machines to help them work and to do many useful things.  A wheelbarrow or a wagon is a machine to carry loads.  A sewing-machine helps to make garments for us to wear.  Clocks and watches are machines for keeping time.

5.  A Machine has Different Parts.—­A wheelbarrow has a box in which to carry things, two handles to hold by, and a wheel for rolling it along.  Some machines, like wheelbarrows and wagons, have but few parts, and it is very easy for us to learn how they work.  But there are other machines, like watches and sewing-machines, which have many different parts, and it is more difficult to learn all about them and what they do.

6.  The Body is Like a Machine.—­In some ways the body is more like a machine than like a house.  It has many different parts which are made to do a great many different kinds of work.  We see with our eyes, hear with our ears, walk with our legs and feet, and do a great many things with our hands.  If you have ever seen the inside of a watch or a clock you know how many curious little wheels it has.  And yet a watch or a clock can do but one thing, and that is to tell us the time of day.  The body has a great many more parts than a watch has, and for this reason the body can do many more things than a watch can do.  It is more difficult, too, to learn about the body than about a watch.

7. If we want to know all about a machine and how it works, we must study all its different parts and learn how they are put together, and what each part does.  Then, if we want the machine to work well and to last a long time, we must know how to use it and how to take proper care of it.  Do you think your watch would keep the time well if you should neglect to wind it, or if you should break any of its wheels?