37o POPULAR SCIENCE MONTHLY. 



THE LAKES OF NEW ZEALAND.* 



By KEITH LUCAS. 



" T is difficult to make general statements which will sum up any 

 -*- points in the morphology of the lakes of New Zealand. This 

 difficulty arises in the main from the strange heterogeneity of the lake- 

 basins. It would be hard, for example, to find any points of re- 

 semblance between two lakes such as Taupo and Wakatipu. In the 

 latter the lake-basin seems to be an integral part of the surrounding 

 country; its slopes continue the slopes of the mountain-sides. It is 

 a mountain valley filled with water, and if it were drained dry it would 

 scarcely appear in any way remarkable. Contrast with this the basin 

 of Taupo. It is a trough abruptly sunk in a country which seems 

 wholly unprepared to receive it. The perpendicular cliffs which form 

 its western shore drop suddenly down from among hills whose slopes 

 are comparatively gentle; in one place the cliff even forms a clean 

 section through a large hill, cutting it from base to summit with a 

 perpendicular face over 1,000 feet in height. 



In their relations to the surrounding country, Manapouri may be 

 classed with Wakatipu, and Eotoiti with Taupo. In the former group 

 there is a correspondence between the position of the deepest water and 

 the gradient of the land in the immediate nighborhood ; in the latter 

 group no such relations can be traced. In Wakatipu the greatest 

 heights combined with the steepest gradients are those of the Eemark- 

 ables and Cecil peak, and between these the deepest water lies. In 

 Manapouri the same conditions are fulfilled by the Cathedral peaks 

 and Cone peak. The existence of this relation indicates a rough corre- 

 spondence in type between these two southern lakes and such familiar 

 types as the lakes of the English Lake District. 



A further point of similarity between Wakatipu and Manapouri is 

 the presence in each of a large flat area where the water is deepest. 

 This peculiarity of form is not to be confused with the tank-like form 

 of Taupo. In the former, sloping sides lead down to a level floor, which 

 marks the limit of depth; in the latter, perpendicular sides lead to a 

 level floor, beyond which there is a further slope to the deepest point. 

 In Lake Taupo, the steepest gradient leading to the highest point 

 is found at Karangahape, on the western shore, but the deepest water 

 lies in the northeast part of the lake. In Eotoiti there is a similar 



* Conclusion of an article in the Geographical Magazine for June. 



