96 TJie Midnight Sun. 



earth coincident in level with the position of the sun, or, 

 speaking astronomically, were the equator and ecliptic in the 

 same plane, and were the axis of the earth perpendicular to 

 the orbit, the phenomena of the equinoxes would be those of the 

 whole year, and the temperature of each place, and the length 

 of day and night, would always be those which it has at the 

 dates just given. But neither of these conditions exists, the 

 planes of the equator and ecliptic (or path of the earth round 

 the sun, forming the sun's apparent path in the heavens) are 

 not coincident, but inclined at an angle of 232 degs., and the 

 axis of the earth is therefore tilted out of the perpendicular to 

 its orbit to the same amount. This axis also in its revolution 

 round the sun is invariably directed to the same point ( in the 

 heavens, called the Pole, which is easily distinguished by the 

 well-known Pole Star,* and this constant direction of the 

 axis causes an unequal exposure to the light and heat of the 

 sun during different lengths of the day, and the obliquity o^ 

 the ecliptic also causing the solar rays to fall with very different 

 degrees of vertically on the earth at different times, produce 

 the charming variety of the seasons. To show the importance 

 of these arrangements, let us suppose the axis of the earth had 

 not been inclined to that of its orbit, and mark the conse- 

 quences. Under this condition every portion of the earth 

 during the year would have the duration of the days and 

 nights equal. The sun's rays, falling perpendicularly, would 

 burn up the regions near the equator, and render them unin- 

 habitable. The countries situated between the equator and 

 high latitudes would have the temperature of a mild spring, 

 which would be continuous, and they would be deprived of the 

 beautiful changes of climate we enjoy ; while few, if any, plants 

 would attain maturity, rendering tho existence of animals a> 

 precarious and doubtful matter. But the condition of the 

 regions at a considerable distance from the equator or near the 

 poles, would be very dismal; an eternal winter and continual 

 desolation would prevail in countries where millions of human 

 Ix'ings now live happily. Still worse would bo the result of 

 the earth's axis being placed parallel to the ecliptic — sharp 

 alternations of day and night, heat, and cold for six months at 

 the time, would bo the unpleasant fate of each hemisphere 

 under this slate of things. 



Happily for us, tho axis is inclined, and lias tho constant 

 direction before mentioned ; and to get an idea of the result, 

 lei me ask my young friends to take an orange, as an easily 

 obtained miniature of our globe, and passing a long needle or 



* Tho minute variation in this direction, duo to precession, is of no conse- 

 guence as connected with the seasons, and does not interfere with this explanation. 

 See tlxo author's paper on tho Precession of tho EquinoxeB in tho Intellectual 

 OusEUVEii of June, 1863. 



