It is quite simple to see this, but I daresay you want to know, as all the children--even the elder ones--did, the meaning of one very uncommon word which we find in each of these verses. "What does 'firmament' mean?" they said. I told them that the word conveys the idea of something firm and strong and steadfast; and then I asked Sharley, who has a reference Bible, to look in the margin, and tell me what word she could find there which might be used instead of this uncommon one. She found, as you will find if there are references in your Bible, that the word is there translated "expansion." And what does that mean? You can understand something spread out wide, can you not? Those who turned the Hebrew word into English long ago thought "firmament"--that which stands fast--was a better word than "expansion," which simply means what is stretched or spread out--as the heaven is spread above the earth "like a curtain." The expanse, then, which God made on the SECOND DAY, is what we call, the sky, as we look up and see the "... tapestried tent Of that marvellous curtain of blue and gold," which is high above our heads, and stretches away far, far as our eyes can reach. And this tent, under whose shadow we dwell, is not firm and solid, but is really a globe of vapour, which surrounds us everywhere, and reaches, not all the way up to what we call the blue sky, but very much higher than any bird could fly or balloon float--as high as forty or fifty miles above the earth. God has fixed its height; if it were less, every breath we take would hurt us; if it were much greater, we should be always tired. But before we speak of this atmosphere, or globe of air, which surrounds the earth, I want you to remember, as you read of the work of God on the Six Days of creation, that each one of these Days led, in a beautiful order, to the next, and that in all of them God was preparing the earth, which He had created in the beginning, for the creatures which He had not yet formed. For each kind of creature a place was found fit for it to live in, whether that dwelling-place was the earth, or the great and wide sea, or the boundless fields of air. And each creature, as it came from God's hand, was fitted to live where God had placed it: for every living thing the means of living was provided. Thus on the First of His Days God called for the light. What would the face of all the world be without it? Then on the SECOND DAY He not only provided the place in which the happy winged creatures fly and utter their sweet songs, but that by which all living things, whether they were plants or animals, should be kept alive. I am sure you know that without air you could not breathe; but perhaps you have never thought that without it no plant could live, not even the smallest blade of grass. Every green thing lives by breathing the air, and if there were no air which it could breathe, it would soon die.