studied and found explanations, he would doubtless fall into the same mistakes that men of ancient days fell into long ago.

He would feel sure that this flat Earth on which he had a footing, which feels so firm and solid, must certainly be at rest. Therefore, he would feel no less sure that the whole sky, with Sun and Moon and hosts of stars, must be whirling round and round our Earth, once in every twenty-four hours.

That would indeed be a tremendous feat for the heavens to perform! Wonderful things are done in the sky; but nothing quite so utterly and hopelessly beyond all human imagination as this!

Only, in far-back days it was not beyond imagination, because men then knew so very little of the real size of our marvellous Universe, or of the enormous numbers of stars contained in it, or of the stupendous distances which divide its stars one from another. To the mind of a man in those times it was much more difficult to imagine that our world could spin day and night like a huge top, than that the entire heavens should perpetually whirl round and round us.

Of the two explanations one had to be true; and it was just a question which was the more easy to accept. Men believed that which seemed to them the simpler.

Now that we know better what would be meant by such a whirl, we realise how very much more simple and easy is the explanation founded on the idea of our small Earth's daily turning on her own axis.

Astronomers gradually discovered that many other

bodies in the sky-the Sun, for instance, and the planets -are steadily spinning or revolving, each on its own axis, some more quickly, some more slowly. Examined through a telescope, they are clearly seen to do So. And if other bodies, many of them far larger than this world, are known to behave thus, why not the Earth also? The idea, far from looking impossible, has become an every-day fact.

When once we grant that our world is ever spinning round and round, carrying with her everything on and near her surface, then the daily movements of the Sun, the nightly movements of Moon and stars, are explained. We see them seem to move, merely because we ourselves are moving. We see them seem to come up from the east and go down in the west, because we on Earth are being carried from west to east. It is much the same as when a man, journeying in a train from north to south, sees trees and fields and villages appear to travel from south to north.

Not that this particular movement, this daily whirl of our Earth is her only movement! And not that the Sun and Moon, the planets and stars, have not real movements of their own! But just now all we have to do with is the fact that the daily and nightly whirl of the skies round us is not real. It is only an appearance, brought about by the ceaseless spin of our small Earth. Other movements may be left alone for a while.

66

'Mysterious Night; when our first parent knew

Thee from report Divine, and heard thy name,
Did he not tremble for this lovely frame,

This glorious canopy of light and dew?

B

Yet 'neath a curtain of translucent dew,

Bathed in the rays of the great setting flame,
Hesperus with the host of heaven came,

And lo, Creation widened in man's view.

Who could have thought such darkness lay concealed
Within thy beams, O Sun? or who could find,

Whilst fly and leaf and insect stood revealed,
That to such countless orbs thou mad'st us blind?
Why do we then shun Death with anxious strife?
If Light can thus deceive, wherefore not Life?
BLANCO WHITE.

III. THE SHAPE OF OUR EARTH.

A man standing on the equator is carried, in the course of twenty-four hours, right round under the entire heavens. If he were gazing through all those hours steadily up into the sky he might view the whole landscape of stars visible from this world-but for one hindrance. That hindrance is the radiance of sunlight, which in day-time shuts off the dim flicker of starlight. Could he cover up the sun, and so secure twenty-four hours of darkness, he might survey all at a single stretch.

Not that the heavens would journey round him, while he stood on a fixed and motionless world, but that he, on the whirling surface of our revolving globe, would be carried round swiftly under each part of the sky in turn, travelling always from west to east.

But a man standing farther north or farther south, and not on the equator, would not gain so full a view. Portions of the heavens would be hidden from him by the intervening solid body of the Earth.

There are many stars over the region of the south

pole, which we in Britain and in other northern parts of Europe and North America can never see. And there are many stars over the region of the north pole, which people in southern Australia and South Africa can never see. It is only from the equator that a man might obtain a complete view.

Since the Earth is not, as was once supposed, a flat plain, reaching to endless distances, but a round globe or sphere, its surface curves away from us, wherever we happen to be, till it passes out of sight at the horizonline. The curve is very gentle; but it is found in all parts of the world alike.

A very interesting proof of the round shape of our Earth is given in an eclipse of the Moon.

Sometimes in our yearly journeying round the Sun -this is another of the Earth's movements-we pass exactly between the Sun and the Moon, so that the three bodies are in a direct line. More often it happens that either the Sun or the Moon is just a little higher or a little lower; and then the three are not in a line. when it does so come about, the Sun casts a shadow of the Earth upon the Moon. And since the latter shines only by reflected sunlight, she at once becomes dim.

But

And-note this !-the shadow thrown by our Earth is a round shadow. As the grey shade creeps slowly over the bright Moon-face, it is always a rounded edge which moves onward. No matter which part of the Earth has its shadow cast, the result is the same. England, India, Australia, America-these or other countries may face the Moon; but invariably the

creeping shadow is round in shape, and the back-edge following is round also.

If you hold up an orange between a lighted lamp and the wall—rather near the wall, and not too near the lamp-you will see that the shadow thrown by it is a round shadow. Turn it about as you will, offer one side after another to the lamp, and still the shadow will be round.

Then hold up a flat plate to the lamp; and you will find that the shape of the shadow depends on how you place it. In one position, and one only, it will cast a round shadow. In others the shadow will be more or less oval; while, if you hold the plate edgeways towards the lamp, the shadow becomes only a straight, broadish line.

Do you see how strong a proof is given here as to the shape of the Earth? And it is one that comes again and again, every time we have an eclipse of the Moon.

And now about the size of the little world on which we live.

If a road could be made straight through its centre, from one side to the other, perhaps on the equator, such a road would be nearly eight thousand miles long. A carriage drawn by quick horses, going at the rate of ten miles an hour, never lessening speed by day or night, might accomplish that distance in thirty-three days, or just over a calendar month. A train, or a motor-car, travelling fifty miles an hour, without a single break, might do the same in less than a week.

But with horses and engines, not to speak of passengers, halts are needed. And when we romance