Page:Journals of Several Expeditions Made in Western Australia.djvu/20

 prove unsuited to the purposes of navigation, they will still afford ample sites for mills, and place an immense water power at the disposal of the settlers. It is said that some of the mountain torrents dry up in summer, while others, on the contrary, in rainy seasons, expand and swamp great districts of level land. The first objection may be advanced with equal truth, against the rapid mountain rivulets in our own island; and the second, in all probability, we shall be able to show, is a curable complaint. In very many instances, the channels, water courses, or beds of the rivers, are obstructed by huge trunks of trees, that at their first decadency form substantial and convenient bridges, but after awhile, their own weight bringing them deeper, they become a perfect dam, and throw back the obstructed waters upon the level district. This injury would not continue to be sustained by improving settlers; it is too serious to be borne while the remedy is so easy.

Such advances towards civilization certainly presuppose a tolerable supply of labour, more than can, with truth, be stated as now existing in those retired districts. It is possible, also, that these swamps may arise from another cause, such as the gushing up of a subterraneous river—an event of frequent occurrence in countries of limestone