Haast. — Address. 43 



At last, in 1860, von Baer brought forward Lis liypotliesis that such 

 changes in one particular direction could be only caused by the rotation of 

 the earth, and he explained the modus operandi in the following manner : — 

 Any given point at the equator makes, naturally, during the daily rotation 

 of the earth, a quicker movement towards east than one in higher latitudes 

 or at the pole. Now, if a body moves gradually from the equator towards 

 the pole, it will possess a larger velocity of rotation than the ground to 

 which it advances, and will move quicker towards east than the objects 

 which surround it. A river in the northern hemisphere, flowing towards 

 north, thus arrives in latitudes which possess a smaller velocity of rotation 

 than itself. Its banks will, as it were, remain behind in the rotating 

 motion, and consequently its waters will push towards east, or against the 

 right bank. If, on the other hand, a river in the northern hemisphere 

 flows towards south, it is evident, when its waters arrive in latitudes with 

 a higher velocity of rotation, that its banks wiU, as it were, advance ahead 

 of the water, and consequently the latter will exercise a greater pressure 

 towards west, or towards the right ; so that again the right bank will be 

 washed away. Of course this effect will be the more powerful and conspicuous 

 the more the direction of the river coincides vnth the meridian. It is 

 natural that in the southern hemisphere the direction will be reversed, so 

 that all the rivers mil push towards the left. According to von Baer aU 

 the large Eussian rivers, as for instance the Volga, Ural, Ob, and Jenessei, 

 and, as von Hochstetter states, the Danube between Vienna and Belgrade, 

 show the correctness of the theory ; and lately searching through the 

 published accounts of travels in North America and Canada I find that 

 similar observations have been made in those countries. 



The application to our ovrn rivers in New Zealand is also easily made, 

 and shows that they conform to this law. Thus, for instance, the rivex- 

 traversing the Canterbury Plains, which flows nearest in a meridional line, 

 is the Eangitata, and there, as x>reviously observed, the difference between 

 the right and left bank is most conspicuous, whilst all the other rivers 

 without exception show in the same way a marked tendency to advance 

 towards their left or northern banks. None of our rivers have been watched 

 so continuously and anxiously as the Waimakariri, and although the 

 tendency of its waters, princixDally during freshes, to wash its northern or left 

 banks away, was well recognised, no vera causa for such direction could 

 be assigned, except, as I had assumed in my report on the formation of the 

 Canterbm-y Plains, that a small local rise of Banks Peninsula was probably 

 taking place. However, as this tendency of the Waimakariri to advance 

 with its waters towards the left is the outcome of a general law, and may 

 be considered constant, the southern banks wiU every year become more 



