On the other side, we have the expression about opening the _windows_ of heaven when it rained at the time of the Flood,[15] which is sometimes thought to imply openings in a solid firmament. But it need not be taken literally, any more than that about the _doors_ of the sea;[16] especially as in another place the _heavens dropping water_ is explained as meaning that the clouds dropped it.[17] And since God promised that in future when a _cloud_ was seen it should not cause another _flood_,[18] it is clear that the flood was thought to have come from the clouds, and not from any openings in a solid reservoir in the sky. [Footnote 15: Gen. 7. 11; 2 Kings 7. 2; Mal. 3. 10.] [Footnote 16: Job 38. 8-11.] [Footnote 17: Judges 5. 4 (R.V.).] [Footnote 18: Gen. 9. 14.] There is also the passage about the sun and moon being _set in the firmament_. But the writer cannot have meant they were _fastened_ to the firmament, since the moon keeps changing its position relatively to the sun, just as a rainbow often does in regard to the cloud in which it is also said to be _set_.[19] Of course their being in the firmament at all, is not correct if this means only the air. But the word may be used here in a wider sense, like the English word _heaven_, to include both the air, and the space beyond. For we speak of the clouds of heaven, and the stars of heaven, and in neither case with any idea of their being _heaved up_, which is said to be the literal meaning of the word. And in its primary sense, as we have shown, the firmament or _expanse_ between the upper and lower waters (the clouds and the seas) must mean the _air_. And the order in which this is placed after light, and before plants and animals is obviously correct. [Footnote 19: Gen. 9. 13.] (4.) _Dry land._ We now come to an important point, the appearance of _dry land_. According to Genesis, there was not always dry land on the earth; the whole of it was originally covered by the waters. And science shows that this was probably the case; the earth being at first surrounded by watery vapours, which gradually condensed and formed a kind of universal ocean. And then, when the surface became irregular, through its contracting and crumpling up, the water would collect in the hollows, forming seas, and dry land would appear elsewhere. But how was it possible for the writer of Genesis to know all this? There is nothing in the present aspect of nature to suggest that there was once a time when there was no _dry land_; and if it was a guess on his part, it was, to say the least, a very remarkable one. (5.) _Vegetation._