remarked that in the regions in which there is the greatest amount of precipitation nature has provided, in the thick turfy mould, as well as in the denser growth of the ferns, mosses, &c., a proportionately greater vehicle for the absorption and retention of the moisture. A considerable quantity of the water soaks into the soil, to be taken up as it is required by the roots of the growing trees, or to filter down to supply the springs that feed the head-waters of the streams; while the remainder — but a small portion of what has left the clouds — trickles gently down to the nearest outlet.

The removal of the forest quickly changes all these conditions. The first thing to happen is the erosion of the surface. No longer held back by the vegetable growth, the storm-water flows off the hillside like rain off the roof of a house, carrying away the ashes of the burnt timber with what is left of the rotted humus, channelling the lighter soil with frequent watercuts, and bodily removing the most fertile portions. Then, as the network of roots decay, landslips occur in the steeper places—it is not unusual for a whole hillside to slide away into a gully—when the débris will be swept down, scouring the bed and sides of the creek, and covering the land below with a deposit of rocks and clay. When the ground affected forms part of a mountain district of large area, in which the creeks have a long course and several branching confluents, it often happens that the débris from a side creek or blind gully will form a temporary dam in the bed of the main stream. If this occur while heavy rain is still falling, a lake is immediately formed by the water from the hills above; and before long the obstruction carries away, when all the mineral detritus, together with the wreck of the ruined forest, is borne down by the foaming torrent to spread destruction below. Just such a catastrophe occurred among the Tokatea Ranges in 1882, when every bridge in Coromandel was carried away and kauri logs were stranded in the main street.

The most destructive floods occur when the water from an elevated region has to traverse a level country before reaching the sea, and the longer the course the greater is the damage. The floods which inundated the City of Paris in December last year (1909) are a case in point. The water was supplied by the unseasonable melting of the snow on the lofty plateau of Langres, where the River Seine takes its rise; but the fact that much of the plateau had been recently cleared of forest caused the water to run down much more quickly than it would otherwise have done, when the winding channel through the level country was unable to carry it off.

An instance more familiar to most of us is that of the great floods that took place in the Hawke's Bay and Palmerston districts in 1893, and again two or three years later. Phenomenally heavy rains had fallen along the watershed inland and down to Cook Strait. Every creek and river was flooded to an unusual height, and where, as in the Hawke's Bay District, a wide extent of level country intervened between the hills and the sea the same thing occurred as that which happened in the valley of the Seine. Rivers left their beds and cut new channels through the plains; from Napier to Wanganui roads and railways were cut through, and bridges and culverts were swept away; stock was drowned; and farms and townships were laid under water. People said that the height of the flood was unprecedented. Possibly it was; but there is no doubt that the ununusual height was in a great measure due to the increasing extent of clearing on the high lands where the rivers have their origin.