Fifth book of lessons for the use of schools . re mostparticularly interested, we shall explain the effectsresulting from its annual and diurnal motions; but forthis purpose it will first be necessary to make you ac-quainted with the artificial terrestrial globe. Thisglobe, or sphere, re-presents the line ab whichpasses through itscentre, and onwhich it turns, iscalled its axis;and the two extre-mities of the axis pare the poles, dis-tinguished by thenames of the northand the southpole. The circleCD, which dividesthe globe into twoequal parts betweenthe poles, is called the equator,
Fifth book of lessons for the use of schools . re mostparticularly interested, we shall explain the effectsresulting from its annual and diurnal motions; but forthis purpose it will first be necessary to make you ac-quainted with the artificial terrestrial globe. Thisglobe, or sphere, re-presents the line ab whichpasses through itscentre, and onwhich it turns, iscalled its axis;and the two extre-mities of the axis pare the poles, dis-tinguished by thenames of the northand the southpole. The circleCD, which dividesthe globe into twoequal parts betweenthe poles, is called the equator, or equinoctial line ;that part of the globe to the north of the equator itthe northern hemisphere ; that part to the south of theequator, the southern hemisphere. The small circleef which surrounds the north pole, is called the arcticcircle; GH, surrounding the south pole, the antarcticcircle. There are two intermediate circles, betweenthe polar circles and the equator, that to the north, ik,called the tropic of Cancer: that to the south, lm,. THE TERRESTRIAL GLOBE. 301 called the tropic of Capricorn. Lastly, the circle LK,which divides the globe into two equal parts, crossingthe equator, and extending northward as far as thetropic of Cancer, and southwards as far as the tropic ofCapricorn, is called the Ecliptic. The delineation ofthe ecliptic on the terrestrial globe may convey falseideas; for the ecliptic is an imaginary circle in theheavens, passing through the middle of the Zodiac,and situated in the plane of the earths orbit. In orderto understand the meaning of the earths orbit, let ussuppose a smooth, thin, solid plarfe cutting the sunthrough the centre, extending out as far as the fixedstars, and terminating in a circle which passes throughthe middle of the zodiac. In this plane the earthmoves in its revolution round the sun; it is thereforecalled the plane of the earths orbit; and the circle inwhich this plane cuts the signs of the zodiac is theecliptic. The spaces be
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