3. Periodical and Continuous Rains,. 4. Rains of the Western Hemisphere,. 5. Rains of the Eastern Hemisphere, 4. Persia. 5. Iran. 6. Afghanistan, 7. Beloochistan. 8. Hindostan, 10. Indo-China. 11. British Provinces, 12. Malacca. 13. Chinese Empire. 14. China,. 15. Toorkistan. 16. Siberia. 17. Japan, Exercises in Voyages and Travels, CHAPTER VIII. POLITICAL DIVISIONS OF AFRICA, § 1. Inhabitants and Countries. 2. North Africa, 5. Western Africa,. 6. Central Africa. 7. African Islands, Table of the Number of Geographical Miles in a Degree of Longi- tude, under each Parallel of Latitude, according to the spheroidal INDUCTIVE LESSONS. INTENDED AS ORAL EXERCISES BY THE TEACHER. I. WE often want to ascertain distances and heights, when neither foot-rule, yardstick, nor measuring tape is at hand. This deficiency in instruments may be supplied, in some degree, in various ways. Take a carpenter's rule, or a yardstick that is graduated into feet and inches, and measure off on the school room floor, or elsewhere, a rod in length, marking the extremes in some suitable manner. Then let each pupil determine for himself, by pacing it off, how many paces of his natural gait in walking are equal to one rod, or half a rod; also how many feet and inches are equal to one of his paces. Let this be practised until it becomes a ready means for measuring horizontal distances. Then ask one to ascertain the length of the school room, and another its width. Having previously determined for yourself the actual distances between a variety of objects or points in the vicinity of the school house, send out three or four pupils to pace off these distances, and report to you the result in rods, yards, and feet. II. To measure heights and depths, let each pupil determine his own height in feet and inches, and then mark an equal height on the wall or fence. Taking his stand at some distance from the wall, let him fix his eye upon the space indicating his height, till he becomes familiar with it as a measure of altitude. Prove its utility by requiring him to determine the height of certain objects. However well furnished your school room may be with surveyors' instruments, these ready means of measurement should not be neglected. It is well to teach young persons to be fertile in expedients. An anecdote may serve to show this. An engineer in the French service was unexpectedly called upon by his superior officer to determine the width of a certain river. He had no instruments with him, and the result must be given without delay. His reputation, nay, his office, was involved in the dilemma. Without the least perturbation of manner, he took his stand on the river's bank, carefully adjusted the fore-point of his chapeau in front of his left eye, and with this as his line of direction, he observed where the point of sight would fall on the opposite bank. Then keeping his head and body rigidly fixed, and making his left heel a centre of motion, he turned a quarter round; and noticing where that point of sight fell on his own side of the river, he marched up to it, counting his paces, and gave the width of the river. 66 III. We will now suppose that the learners are prepared to take a tour of survey. Let the scene of their first exploration be the school room. Select some object for a starting point, your own desk, for example, and ask, "How far is my desk from the nearest wall?" Let several measure the distance. In like manner determine the position of various other objects in the room, both with relation to your desk and to each other. Now inquire, "If I wish to make a picture or ground plan of our school room, so as to present each object and part in its natural size, how large a sheet of paper will be necessary?" They answer, "As large as the school room floor." Right; but this is impracticable. I want to draw it on our blackboard, which, you see, is very much smaller in surface: how can it be done?" Some one answers, "By making the picture of each object smaller." Very well: but in order to preserve a just proportion in the parts of the picture, it will be necessary to fix upon a scale of measurement. Let us take, as the unit of a scale, one inch to a foot. I will divide this horizontal line" (drawing it on the board) "into twenty-four or thirty-six inches, to represent twenty-four or thirty-six feet. Next, let this figure" (drawing it by the scale) "represent the outline of the school room floor." Having progressed thus far, direct some member of the class to take the crayon, and say, "Locate on the plan, and that by actual measurement, the teacher's desk, the table, the stove, or the door." Give each member of the class a chance to do something upon it. When completed, question them as to the details of the plan, to ascertain how far its purpose is understood. For example, (pointing to the location of the teacher's desk on the plan,) ask, "What is this?" "Your desk." Why, no. This" (putting your hand on the desk itself) "is my desk." Some will then say, "It is a picture of your desk." "Yes; but my desk is very much larger than the picture; is it not?" "It is; but the picture is made small because the blackboard is not large enough for one of natural size." Pointing to the whole plan, "Now, if you should meet with this or a similar picture when you are at home or elsewhere, of what would it remind you?" "Our school room." "Would you think of the room and its furniture as being small, like the 66 |