XXVII.  And with respect to the Sea even if I did not marvel at its greatness, yet I should have marvelled at its gentleness, in that although loose it stands within its boundaries; and if not at its gentleness, yet surely at its greatness; but since I marvel at both, I will praise the Power that is in both.  What collected it?  What bounded it?  How is it raised and lulled to rest, as though respecting its neighbour earth?  How, moreover, does it receive all the rivers, and yet remain the same, through the very superabundance of its immensity, if that term be permissible?  How is the boundary of it, though it be an element of such magnitude, only sand?  Have your natural philosophers with their knowledge of useless details anything to tell us, those men I mean who are really endeavouring to measure the sea with a wineglass, and such mighty works by their own conceptions?  Or shall I give the really scientific explanation of it from Scripture concisely, and yet more satisfactorily and truly than by the longest arguments?  “He hath fenced the face of the water with His command.” Job xxvi. 10.  LXX.  This is the chain of fluid nature.  And how doth He bring upon it the Nautilus that inhabits the dry land (i.e., man) in a little vessel, and with a little breeze (dost thou not marvel at the sight of this,—is not thy mind astonished?), that earth and sea may be bound together by needs and commerce, and that things so widely separated by nature should be thus brought together into one for man?  What are the first fountains of springs?  Seek, O man, if you can trace out or find any of these things.  And who was it who cleft the plains and the mountains for the rivers, and gave them an unhindered course?  And how comes the marvel on the other side, that the Sea never overflows, nor the Rivers cease to flow?  And what is the nourishing power of water, and what the difference therein; for some things are irrigated from above, and others drink from their roots, if I may luxuriate a little in my language when speaking of the luxuriant gifts of God.