Part 3

_Fig. 1._ _Fig. 2._ _Fig. 3._ _Fig. 4._ _Fig. 5._ _Fig. 6._ ]

You will observe from a close inspection of these figures, that the whole extent of land on our globe is nearly equal to that of a temperate zone; and that if it were possible to unite America, Europe, Asia, Africa and Australia into one, their united extent would not yet fill one of the temperate zones! You will also perceive that the two temperate zones occupy together the greatest portion of the Earth’s surface, and that the arctic zones occupy comparatively the smallest.

RECAPITULATION OF LESSON VI.

QUESTIONS.

[§ 32.] Do we know anything about the Interior of our Earth? Why not? What does the surface of our Earth consist of? What proportion does the land bear to the water? What are the great lands called? What, the great waters? What are smaller portions of land, surrounded by water, called? What, small portions of water, surrounded by land?

[§ 33.] Into how many continents is all the land of our Globe divided? What are they? Are all the continents of our globe of the same extent? Which is the smallest of them? Which are the largest? Explain Plate, No. XI.

What proportion does the extent of America bear to that of Asia? What relation do these continents bear to Europe or Australia? What is the next greatest portion on our globe? Which continent is the smallest? What relation does the surface of the Moon bear to America or Asia?

[§ 34.] Is the whole Earth equally illumined or heated by the Sun? Why not? What is, therefore, the surface of our Earth divided into? Upon what portion of our Earth do the Sun’s rays fall perpendicular? What portion do they strike more obliquely? What people, therefore, will experience the greatest heat?

[The pupil ought now to explain Plate XII. The elder pupils ought to draw a sphere with the Equator, the tropic and arctic circles. They ought also to draw the Diameter of the Earth, and indicate the North and South Pole.]

[§ 35.] If you compare the whole extent of land on our globe to the Contents of one of the temperate zones, what proportion do you find them to bear to each other? If it were possible to unite the five great continents, America, Europe, Asia, Africa and Australia, what zone would they nearly fill? What two zones occupy the largest portion of the Earth’s surface? What two, the smallest?

APPENDIX

CONTAINING THE COMPARATIVE POPULATION OF THE DIFFERENT QUARTERS OF OUR GLOBE.

[The numbers are given in Table III.]

§ 36. The Five principal parts of our globe, America, Europe, Asia, Africa and Australia are not equally thickly settled. Europe and Asia have, in proportion to their extent, the greatest population; America and Australia the least.—The following Plate, No. XV, shows the comparative population of these continents.

Fig. I represents the whole surface of land on our globe, inhabited by nearly One Thousand Millions (One Billion) human beings. If these were to live throughout as close together as in _Europe_, then they would only occupy a surface of land as large in proportion, as the inner circle marked _a_. But the two rings, _b_ and _c_, occupy each as much surface as the circle _a_; hence there is yet room for twice as many human beings; before each quarter of the world is as thickly settled as Europe.

Fig. II represents _Asia_ and its population. If this quarter were settled as thickly as Europe is, then its inhabitants would only fill the inner circle marked _b_; the ring _a_, therefore, is still left for settlement.

Fig. III exhibits the population of Africa. If the inhabitants of this continent lived as close together as those of Europe, they would only fill the inner circle, marked _c_, and the surrounding ring might yet be inhabited.

Fig. IV shows the comparative population of America. Its inhabitants, crowded together as the inhabitants of Europe, would only occupy the small circle _e_; the whole broad ring _f_, therefore, is still left for settlement!!

Fig. V represents Australia. Its inhabitants, settled as in Europe, would only fill the circle _a_.

Fig. VI represents the population of Europe filling the whole of that Quarter.

The whole of these Six figures may represent to the pupil the comparative extents of the five great continents of our globe; but the _inner circles_ of these figures, and the whole of the sixth figure, show their comparative populations. From a close inspection of this plate the pupil may learn:

1. That the population of Asia is yet greater than that of all the rest of the world. (The circle _b_ in figure II being yet larger than the inner circles of all the other figures, and figure VI taken together.)

2. That the population of Europe is as yet larger than that of America, Africa and Australia, taken together.

3. That the population of Africa is larger than the joint populations of America and Australia.

4. That America if once settled as Europe is, will have more than Six times her population.

[The teacher, if he think proper to ask the pupils some questions in reference to the Appendix, will find no difficulty in adapting them to the capacity of his pupils.]

TABLE I.

_Showing the Diameter, Surface, and Cubic Contents of the Sun and the Planets._

Diameter in Surface in Cubic Contents Geographical Geographical in Geographical Names. Miles. Square Miles. Cubic Miles. SUN, 194,000 118,093,000,000 3,825,903,253,970,000 Mercury, 608 1,161,314 117,659,099 Venus, 1678 8,844,063 2,473,469,743 Earth, 1719 9,282,066 2,659,159,061 Mars, 1006 3,178,805 532,996,317 Vesta, 74 15,000 2,121,347 Juno, 309 282,690 2,355,750 Ceres, 352 389,182 22,832,034 Pallas, 465 650,266 52,886,472 Jupiter, 19566 1,202,280,406 23,533,143,597,631 Saturn, 17263 936,530,620 2,757,547,946,775 Herschel, 7564 173,696,911 1,359,227,438,858 Moon, 480 723,686 51,561,578

TABLE II.

_Showing the exact Duration of the Revolutions of the different Planets round the Sun._

Duration of the Planets. Years. Days. Hours. Min. Sec. Moon’s revolution round the Earth. Mercury, — 87 23 15 44 27 days, 7 hours, 43 Venus, — 224 16 49 10 minutes, and 12 Earth, 1 — 6 9 8 seconds. Mars, 1 321 22 18 31 Vesta, 3 225 — — — Juno, 4 131 10 30 — Ceres, 4 220 13 4 — Pallas, 4 221 15 35 — Jupiter, 11 314 20 39 — Saturn, 29 166 2 — — Herschel, 83 266 9 — —

TABLE III.

_Showing the Extent and Population of the five great Continents._

Names of the Continents. Extent in Sq. Miles. Population. America, 14,868,000 40,000,000 Europe, 3,292,000 198,000,000 Asia, 15,000,000 500,000,000 Africa, 11,267,900 150,000,000 Australia, 3,823,200 1,500,000

The United States, 1,781,926 13,000,000

POPULAR LESSONS IN ASTRONOMY, ON A NEW PLAN;

IN WHICH

SOME OF THE LEADING PRINCIPLES OF THE SCIENCE ARE ILLUSTRATED BY ACTUAL COMPARISONS, INDEPENDENT OF THE USE OF NUMBERS.

BY FRANCIS J. GRUND,

AUTHOR OF “AN ELEMENTARY TREATISE ON PLANE AND SOLID GEOMETRY,” “ELEMENTS OF NATURAL PHILOSOPHY AND CHEMISTRY,” &c. &c.

BOSTON: CARTER, HENDEE, AND CO. 1833.