The Sea Lions

Chapter 22

Now, the first thing that the student is to fix in his mind, in order to

comprehend the phenomenon of the seasons, is the leading fact that the

earth does not change its attitude in space, if we may so express it, when

it changes its position. If the axis were _perpendicular_ to the plane of

the orbit, this circumstance would not affect the temperature, as the

simplest experiment will show. Putting the equator of a globe on the outer

edge of the table, and holding it perfectly _upright_, causing it to turn

on its axis as it passes round the circle, it would be found that the

light from the centre of the table would illumine just one half of the

globe, at all times and in all positions, cutting the two poles. Did this

movement correspond with that of nature, the days and nights wo