LESSON XII.
CLIMATE AND ZONES.
Preparatory Oral Work.—Keep on the board a daily record of temperature and rain for two weeks preceding this lesson. Now turn to this record and teach the terms weather and climate. Ask on how many days we have had wet weather; on how many dry weather; whether our climate is wet or dry.
1. Climate.—We have learned that the sun gives us heat and light, and that besides this, it makes the vapor rise from the sea, and so causes the rain to water the earth.
But the sun shines upon the earth in such a way that it warms and waters some parts of it much more than others.
Some parts are very hot; some are bitterly cold; others are sometimes hot and sometimes cold. So, too, some parts of the earth are very rainy; in some there is hardly any rain at all; in others there is neither too much nor too little rain.
The heat or cold, and the moisture or dryness of a country for all the time make up what is called its climate. When we speak of these for a short time, as a day, or a week, we use the word weather.
A country that has much more hot weather than cold during the year has a hot climate; one that has cold weather the greater part of the year has a cold climate; and a country in which the hot and cold parts of the year are nearly equal has a temperate climate. The climate, again, may be moist or it may be dry.
The zones.
2. Zones.—Look at the picture. The red belt shows that part of the earth which receives the most heat from the sun, and in which the most rain falls. This is called the Torrid or hot zone. Zone means belt.
Across the middle of the picture is a line which divides it exactly into halves. We imagine such a line to go all round the earth. It is called the equator. The Torrid zone lies on both sides of it, and the sun is always shining straight down on some part of this zone.
The white belts represent the parts of the earth which receive little heat, and where the air is always cold. These are called the Frigid or frozen zones.
We see at the top and bottom of the picture two little while dots. These show the points of the earth's surface that are farthest away from the equator. We call these points the north pole and the south pole. The Frigid zones lie around them. There is at least one whole day in each year during which the sun does not shine upon any part of these zones.
The yellow belts show where there is a summer and a wintcr, and where both the heat and rain are less than in the Torrid zone. These are the Temperate or mild zones. Here the sun never shines straight down, but it never fails to shine during some part of every day.
There are two Frigid zones and two Temperate zones. These are known as the North Frigid zone and the South Frigid zone, and the North Temperate zone and the South Temperate zone.
We must go quite far north or south of the place where two zones join before we notice that the zone we are in differs from that which we left. However, if we should climb up a high mountain, in either of the Termperate zones or even in the Torrid zone, we would notice that the climate soon becomes colder and colder the farther we go up above the lowlands.
The climate of a country depends chiefly on its being in one or another of these zones.
In the Frigid zones we should see mountains of ice and endless fields of snow.
The people live in huts of snow and ice. They dress in fur and even then can hardly keep warm.
