Next, the configuration of the catchment area in its main features is of great importance. This consists of the Mount Ida range and the Kakanuis on the north; the Rock and Pillar, Lammerlaw, and Rough Ridge on east, south, and west; and the Upper Taieri or Maniototo Plains in the centre, which latter average about 1400 feet above sea-level. And, lastly, the soil generally over the whole area is dry, in many places shingly, and, as a whole, has become so baked on the surface by grass fires and stocking that the rainfalls run off with great rapidity—greater, it is thought by many, than was the case before the interior was settled. But there is one remarkable exception to this general character of the soil. The plateau, or elevated plain which forms the top of the Lammerlaw and Rock and Pillar Mountains, contains a large morass of 3000 acres in extent, besides numerous smaller swamps, with bogs and lagoons. This sponge like and porous soil, with lagoons, is more or less characteristic of the whole catchment area of the Taieri, above the Styx Stream, including the Serpentine Flat, 1800 feet above sea-level. Effects. Bearing in mind, then, these facts—the direction of the rainstorms which, at their worst, come from S.E. to S.W., the exposure and resistance offered by the faces of the mountains to these storms, and the nature of the soil on the mountain tops and on the plains, with the relative heights of these localities—what should we expect? We should expect the rain-clouds, which come up in a storm from the Southern Ocean, on reaching our coast, and losing the contents of their lower strata among the coast hills, would pass on until caught by the higher ranges which surround the sources of the Taieri River. There, rolling up the slopes of the Lammerlaw and Rock and Pillar Mountains, and forming an eddy on the flat summits, they would become piled up, and their rate of travelling or velocity being thus reduced, they would naturally deposit the greater portion of their contents on and around the tops of these ranges. The remainder of the rain-clouds would pass on and become gradually dispersed by the higher temperature of the interior plains. The more northerly columns of the rain-clouds would draw along the Horse Range to the highest peaks of the Kakanui Mountains and Kyeburn Hill, and lose the greater amount of their contents among these peaks. At the same time the Maniototo Plain itself, lying immediately west of these ranges, together with its western boundaries, the Mount Ida Range and northern part of the Rough Ridge, would have but a reduced balance of rainfall to receive, reduced still further by the superior warmth of the plain itself. Evidences of Distribution of Rainfall. And what do we find to be the case? The experience of the oldest settlers on the Upper Taieri Plains goes to show that the above theory is correct. For instance, Mr. James Murison, who first took up country there as a runholder in 1857, has assured me that, while the southerly storms rage around the Lammerlaw and Rock and Pillar, the basin of the Upper Taieri River itself escapes these to a great extent. From the Kyeburn, all round the north and west side of the plain to the Totara, that is over an area of 280 square miles, or 180,000 acres, there is not a single stream but such as a man may easily jump across. The Kyeburn stream has a rapid descent, and in floods rises to a considerable height, but falls quickly. This I saw during the big flood of 1868, when camped on its banks. The streams then round to the Totara discharge very little rainfall into the Taieri; and the most received by Mount Ida flows into the Waitaki; while on the east side, round to Hyde, there is but a small quantity runs down the Sowburn and Pigburn.* I find from measurements recently made by Mr. D. Barron, that the average discharge at Hamilton Bridge exceeds that at Pateroa Ford by only 8,000,000 cubic feet daily. But the Deep Stream and Lee Stream rise rapidly and carry off as swiftly a large amount of rainfall. After the flood of February, 1877, I examined parts of the gorge of the Lee Stream, where the flood marks were visible 40 feet above the ordinary water-level on a width of about two to three chains. This gorge has a descent of 900 feet in 11½ miles, while that of the Deep Stream falls 825 feet in 20 miles, or thereby. Then it is well known the main body of the Taieri above the Styx comes away slowly—owing partly, no doubt, to the sponge-like and retentive nature of its catchment ground, and continues high long after the Kyeburn, Deep Stream, and Lee Stream have run off their flood waters. These latter streams are sudden and violent in their action, especially the Deep Stream, which should be checked; but most danger appears to me to lie in the accumulation of rainfall at the sources of the Taieri itself, after the ground there has become saturated and the river has risen to its full capacity. Here, then, the main reservoir should be.