Part 11 (1/2)

(_b_) It will be pushed upward by colder and heavier currents of air from the north and south.

(_c_) If the earth did not rotate, there would be constant winds towards the south, north of the equator; and towards the north, south of the equator.

(_d_) These currents of air are travelling from a region of less motion to a region of greater motion, and have a tendency to lag behind the earth's motion as they approach the equator.

(_e_) Hence they will seem to blow in a direction contrary to the earth's rotation, namely, towards the west.

(_f_) These two movements, towards the equator and towards the west, combine to give the currents of air a direction towards the south-west north of the equator, and towards the north-west south of the equator.

4. _Verification_:

Read the geography text to see if our inferences are correct.

THE DEVELOPMENT OF GENERAL KNOWLEDGE

=The Conceptual Lesson.=--As an example of a lesson involving a process of conception, or cla.s.sification, may be taken one in which the pupil might gain the cla.s.s notion _noun_. The pupil would first be presented with particular examples through sentences containing such words as John, Mary, Toronto, desk, boy, etc. Thereupon the pupil is led to examine these in order, noting certain characteristics in each.

Examining the word _John_, for instance, he notes that it is a word; that it is used to name and also, perhaps, that it names a person, and is written with a capital letter. Of the word _Toronto_, he may note much the same except that it names a place; of the word _desk_, he may note especially that it is used to name a thing and is written without a capital letter. By comparing any and all the qualities thus noted, he is supposed, finally, by noting what characteristics are common to all, to form a notion of a cla.s.s of words used to name.

=The Inductive Lesson.=--To exemplify an inductive lesson, there may be noted the process of learning the rule that to multiply the numerator and denominator of any fraction by the same number does not alter the value of the fraction.

_Conversion of fractions to equivalent fractions with different denominators_

The teacher draws on the black-board a series of squares, each representing a square foot. These are divided by vertical lines into a number of equal parts. One or more of these parts are shaded, and pupils are asked to state what fraction of the whole square has been shaded.

The same squares are then further divided into smaller equal parts by horizontal lines, and the pupils are led to discover how many of the smaller equal parts are contained in the shaded parts.

[Ill.u.s.tration: 1/2=3/6 2/3=8/12 3/4=15/20 3/5=18/30]

Examine these equations one by one, treating each after some such manner as follows:

How might we obtain the numerator 18 from the numerator 3? (Multiply by 6.)

The denominator 30 from the denominator 5? (Multiply by 6.)

13 3 24 8 35 15 36 18 --- = -; --- = --; --- = --; --- = --.

23 6 34 12 45 20 56 30

If we multiply both the numerator and the denominator of the fraction 3/5 by 6, what will be the effect upon the value of the fraction? (It will be unchanged.)

What have we done with the numerator and denominator in every case? How has the fraction been affected? What rule may we infer from these examples? (Multiplying the numerator and denominator by the same number does not alter the value of the fraction.)

THE FORMAL STEPS

In describing the process of acquiring either a general notion or a general truth, the psychologist and logician usually divide it into four parts as follows:

1. The person is said to a.n.a.lyse a number of particular cases. In the above examples this would mean, in the conceptual lesson, noting the various characteristics of the several words, John, Toronto, desk, etc.; and in the second lesson, noting the facts involved in the several cases of shading.