—Mary Rogers Miller: The Brook Book.
(Copyright, 1902, Doubleday, Page and Co.)
+Theme XCIV.+—Write an exposition on one of the following subjects, making use of particulars or details:—
1. How ice cream is made.
2. The cultivation of rice.
3. Greek architecture.
4. How paper is made.
5. A tornado.
6. Description of a steam engine.
7. The circulatory system of a frog.
8. A western ranch.
9. Street furniture.
10. A street fair.
(Have you used particulars sufficient to make your meaning clear? Have you used any unnecessary particulars? Why is the arrangement of your topics easy in this theme?)
+169. Exposition by Cause and Effect.+—When our general statement is in the form of a cause or causes, the question naturally arises in our mind as to the effects resulting from those causes. In like manner, when the general statement takes the form of an effect, we want to know what the causes are that produce such an effect. From the very nature of exposition we may expect to find much of this kind of discourse relating to causes and effects. (See Section 49.)
Notice the following example:—
The effect of the polar whirls may be seen in the rapid rotation of water in a pan or bowl. The centrifugal force throws the water away from the center, where the surface becomes depressed, and piles it up around the sides, where the surface becomes elevated. The water being deeper at the sides than at the center, its pressure upon the bottom is proportionately greater. A similar effect is produced by the whirl of the air around the polar regions. It is thrown away from the polar regions and piled up around the circumference of the whirl. There is less air above the polar regions than above latitude 30°-40°, and the atmospheric pressure is correspondingly low at one place and high at the other. Thus the centrifugal force of the polar whirl makes the pressure low in spite of the low temperature. The position of the tropical belts of high pressure is a resultant of the high temperature of the equatorial regions on one side and the polar whirls on the other.
—Dryer: Lessons in Physical Geography.
+Theme XCV.+—Write an expository theme using cause or effect.
Suggested subjects:—