408 Transactions. — Miscellaneous. 



lu the valley of the "Waikato, near Atiamuri, where the 

 Eotorua and Taupo Eoad crosses the river, a most excellent 

 example of the terrace-formation, and of the wonderful power 

 of the river in denuding its valley, may be seen. The height 

 of the Waikato is 1,200ft. above the sea at its exit from 

 Taupo Lake, where its outflow is 16,300 gallons per second — 

 that is to say, about 3,500 tons of water passes through its 

 channel every minute ; it has therefore as much energy to 

 expend in denudation as would be required to lift this mass of 

 water 1,200ft. above the sea. Naturally, in its highest reaches, 

 where the gradients are steepest, most of the dynamic forces 

 are expended, and therefore here are shown the greatest 

 examples of surface-denudation. 



There are evidences that the upper portion at least of the 

 Patetere Valley, including the Tokoroa Plains, was once 

 occupied by a lake. The stratified pumice-beds and the re- 

 mains of horizontal terraces which are to be seen there indi- 

 cate this. It may be that the Waikato Eiverfor a time flowed 

 into the Patetere by the Mangaharakeke Valley, to the eastward 

 of the Whakamaru Eange; but of this there is not sufficient 

 evidence. We have no well-defined river-bed which the Wai- 

 kato might occupy, and I think it more than probable that the 

 Tokoroa Lake was not formed by the Waikato Eiver. I may 

 here mention a somewdiat strange tradition which was men- 

 tioned to me by the Assistant Surveyor-General as having 

 been related to him by Mr. Lawry : That the Waikato Eiver 

 formerly ran into the sea near Taurauga ; and that in the course 

 of ages it changed its course and ran out into the Hauraki 

 Gulf; and then, again, after a further lapse of time, it ran 

 across by Tuakau and Mauku, and then into the Manukau 

 Harbour ; and thence into the sea at the mouth of the Wairoa 

 Eiver. It is strange what could give rise to this tradition. I 

 do not think the Maoris are speculative in their deductions, 

 and they would be unlikely to draw conclusions of this kind 

 without something more than the surface-configuration of the 

 land to guide them. However, it ia not at all probable that the 

 Waikato Eiver flowed through Tokoroa. The lake owed its 

 origin to other causes, and was drained by the Waikato Eiver 

 through the Kopokorahi Stream. 



The whole surface-configuration of the Patetere Valley 

 bears evidence of the immense effects of sub-aerial denudation. 

 Tokoroa Plain is 1,220ft. above the sea ; the fall from there to 

 Matamata is pretty regular, and amounts to 1,050ft., being at 

 the rate of about 2Cft. to the mile : it is easy to imagine w-hat 

 the effects of denudation would be in a country w^ith such an 

 incline, and covered with loose materials, as we find the Pate- 

 tere was. These effects are shown in the many deep water- 

 courses which furrow the valleys for miles. Most of these are 



