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Ins. per second. Mile per hour. 3 = 0.170 will just begin to work on fine clay. 6 = 0.340 will lift fine sand. 8 = 0.4545 sand as coarse as linseed. 12 = 0.6819 will sweep along fine gravel. 24 = 1.3638 will roll along rounded pebbles 1 inch in diameter. 36 = 2.045 will sweep along slippery angular stones of the size of an egg.

These figures2 have greater interest for us than in the connection at present used, as will be noticed hereafter. We have seen that in rounding the bends (Fig.1) A, B, C, different portions of the stream possess different velocities. We know it is charged with sediment and stones all the time. The tendency, therefore, will be for the large stones and coarse detritus to go round the outer side of the bend, to bombard the banks near the points shown by the arrows, and to erode the channel deepest in those situations; whilst a goodly proportion of the fine muddy sediment will find its way to the quiet and shallow parts near x x x, and in course of time become deposited there, whilst the main course of the stream is eating its way and shifting its course as indicated by the dotted lines a a. This action proceeds, it may be, until the course of the river becomes straighter, as shown by the dotted lines b b, when the whole of the loop B D is abandoned, its former course there being evidenced by pools of water and irregular heaps of gravel, sand and mud. The reader will now see that the whole of the land marked x x x has been formed of sediment brought down by the river, and in the majority of cases such fine silt and sandy mud or clay is specially suitable for brickmaking—many of our largest brickmakers obtain their material from such a source. It should be observed that the valley, as shown between the lines v v, may be two or three miles in width, and it is often much more, so that the actual amount of land made by the river at x x x may be several thousands of acres in extent.