_B._ Because, perhaps, when the water is drawn up higher than the highest mountains, where the course of the air between the equator and the poles is free from stoppage, the stream of the air freezeth it into snow. And it is in those places only where the hills shelter it from that stream, that it falls in rain. _A._ Why is there so little rain in Egypt, and yet so much in other parts nearer the equinoxial, as to make the Nile overflow the country? _B._ The cause of the falling of rain I told you was the stopping, and consequently the collection of clouds about great mountains, especially when the sun is near the equinoxial, and thereby draws up the water more potently, and from greater seas. If you consider therefore that the mountains in which are the springs of Nile, lie near the equinoxial and are exceedingly great, and near the Indian Sea, you will not think it strange there should be great store of snow. This as it melts makes the rain of Nile to rise, which in April and May going on toward Egypt arrive there about the time of the solstice, and overflow the country. _A._ Why should not the Nile then overflow that country twice a year, for it comes twice a-year to the equinoxial. _B._ From the autumnal equinox, the sun goeth on toward the southern tropic, and therefore cannot dissolve the snow on that side of the hills that looks towards Egypt. _A._ But then there ought to be such another inundation southward. _B._ No doubt but there is a greater descent of water there in their summer than at other times, as there must be wheresoever there is much snow melted. But what should that inundate, unless it should overflow the sea that comes close to the foot of those mountains? And for the cause why it seldom rains in Egypt, it may be this, that there are no very high hills near it to collect the clouds. The mountains whence Nile riseth being near two thousand miles off. The nearest on one side are the mountains of Nubia, and on the other side Sina and the mountains of Arabia. _A._ Whence think you proceed the winds? _B._ From the motion, I think, especially of the clouds, partly also from whatsoever is moved in the air. _A._ It is manifest that the clouds are moved by the winds; so that there were winds before any clouds could be moved. Therefore I think you make the effect before the cause. _B._ If nothing could move a cloud but wind, your objection were good. But you allow a cloud to descend by its own weight. But when it so descends, it must needs move the air before it, even to the earth, and the earth again repel it, and so make lateral winds every way, which will carry forward other clouds if there be any in their way, but not the cloud that made them. The vapour of the water rising into clouds, must needs also, as they rise, raise a wind. _A._ I grant it. But how can the slow motion of a cloud make so swift a wind as it does?