Did you ever think how hard it would be to get along without clocks? At almost every city street corner we can look at a clock; every railway station, every post office, every schoolhouse, has at least one; and everybody's house contains one or more. And at that, boys and girls are sometimes late for school.

No, we certainly couldn't manage without these useful mechanisms; and yet, there was a time, not so many centuries ago, either, when they were a rare possession; and a time before that when they had not yet been invented. What did our far-off ancestors do?

Let us pretend that we are going for a walk in the beautiful garden of a country mansion. Here in the midst of a rose bed stands a low stone pillar, with an upright, triangular piece of metal attached to its top near the center, and some figures marked in a circle around the edge.

This is a sun-dial. The owner of the garden has it here for a pretty ornament; but in the old times, before the days of clocks, people told the time by means of sun-dials, judging the hour by the position of the shadow cast by the piece of metal upon the stone. If you would like, just for the fun of it, to have such a sun-clock in your own little garden, there is a very easy way to make one.

Choose a spot of ground that is perfectly flat, where the sun shines all day long. Set up, or get your father or big brother to set up for you, a post four or five inches thick. Make it stand perfectly firm and straight. Now find a thin, flat piece of board—a box top or a shingle will do—and nail it like a table top on to the top of the post. After these preparations have been made, you must wait for a clear, starry night when you can go out and find the North Star. The way to do this is by looking at the "Big Dipper", the group of stars that of course you know.

The two stars marked A and B are called the "Pointers"; and, looking in the direction of the arrow, the next star in line with them is the North Star. Take a straight, thin stick, and fasten it to the center of the top of the post, slanting it so that it will point directly at the North Star. That is all you can do until the next day.

At twelve o'clock, if the sun is bright, you will find your slanting stick casting a shadow on the piece of board. Mark the line where it falls, and put the figure 12 upon it, to show that this line belongs to twelve o'clock. Do the same thing at one, two, and three o'clock, and so on through the afternoon. In the same way, the next day, you can mark the morning hours.

If you like, you can print on your sun-dial the motto that is often used for them: "Non horas sed serenas", which means "I mark none but sunny hours".

Questions

1. What did our ancestors use instead of a clock?

2. How can you find the North Star?

3. Can you draw a diagram of the sun-clock?