Now let us think of some of the things that this wonderful Star of Day does for us. In the first place, he is the great source of light and heat, as he shines, not for us alone, but upon all the other planets—those which are so near to him as to get more heat than we could bear, and those which are so far away that it seems to us as if they must be very cold indeed.
But, if we leave these distant worlds and think of our own, how wonderful it is to know that, as we learnt when speaking of Light itself, not from the sun alone, but from every star, waves of light and heat, like tiny messengers from them to us, are always speeding on their noiseless way. They travel to us through space, or rather through something finer than air or water, which fills all the room between us and them—for no place in the universe is really empty.
You may be surprised to hear that these messengers come from the stars by day as well as by night; but remember that they are always shining in their places in the sky. We cannot see the starlight waves while the sun's great light is shining upon us; but you know how beautifully they shine on clear nights, when there is neither sunlight nor moonlight to quench their soft beams.
But after all, the stars are so far away that we must think specially of our own star, the sun, as the source of light and heat; he also makes for us all form and colour, and gives us the pictures drawn by his light which we call photographs, and which make us know something of people we have never seen, and places which we may never visit.
You remember that sunlight also helps the plants to sift the air, so that they take from it the part that suits them, and leave behind the part that suits us—that precious oxygen which is so necessary for all animal life.
Then we must not forget the work done by the heat-waves. These are called "dark," because they cannot be seen. They not only strike upon the land, waking up the hidden seed, and warming it into life, but they are the great water-carriers. When we were talking about the clouds we learnt that from every wet place, as well as from the seas, lakes, and rivers, water is constantly being drawn up, so that we can see it again in the fleecy clouds which float across the sky, and again when it comes down in the showers which water the earth—the tiny heat-waves are the messengers which perform this work of evaporation.
When we were speaking about the world of water, we learnt that the moon is the chief cause of the tides, by whose constant ebb and flow the ocean and rivers are purified; in like manner the sun, by causing the winds to blow, keeps the air fresh and pure; but this is a subject rather beyond us. We can, however, remember that one more thing which the sun does for us is to tell us the time. God gave him "to rule the day … and to divide the light from the darkness," and he marks how long our day is to be, "keeping time," as May's verse says, all the world over—for he is the great clock which tells the hours and the days—a clock which never needs to be wound up, and which we can trust, for it never goes wrong. And he is a constant silent witness to us of the power and the goodness of God, as "day unto day uttereth speech, and night unto night sheweth knowledge. There is no speech nor language; their voice is not heard"—but "the heavens declare the glory of God … in them hath He set a tabernacle for the sun." If, as we look at our watches, we are certain that men must have made them, how sure is it that God made this great time-keeper, light-giver, and life-sustainer—this mighty magnet that guides and controls the world of which it is the glorious centre!
The sun "divides the light from the darkness" by being seen by us or hidden from our sight. If you watch, after the sun has risen in the morning—and you can watch him in the winter, when you are often up before he is—you will see that he seems to climb the sky, always mounting higher and higher, until he is shining right above your head. Then, as the day goes on, and it gets towards afternoon, he seems to go down, down, until he sinks into the far away place where the earth and sky seem to meet, and we see him no more. It is while he is hidden from sight in the far west, behind that line which we call the horizon, that night wraps us in its deep shade; for the sun, the day-star is, gone.
I wonder whether you have ever thought of this darkness, which would be so dreadful did it last long, as one of the blessings which God has given us. The night is the time of sleep and rest for animals and plants, as well as for weary men and women, and children who can get tired even with their play. God watches over you while you sleep—"the darkness and the light are both alike" to Him—and you get up in the morning fresh, and ready for a new day.
It is while we are in this world, which is a place of toil, and labour, and sorrow, that we need the rest and quiet which the still, dark night brings; but God has said that there is a rest for His people, His Sabbath, which can never be broken; and when He speaks, in the last book of the Bible, of the bright, golden city, He says, "there shall be no night there."