92 Transacttons.—Miscellaneous. 
belonged to the invaders and which to the invaded. I have classed the 
allies, hapus, and sections of hapus of each tribe under one common 
appellation: Maoris may say I am wrong, but I appeal from them to 
the common sense of my English readers, and am hopeful of their verdict 
in my favour. 
Art. VI.—On the Influence of the Earth’s Rotation on Rivers. 
By A. C. Barnes. 
[Read before the Philosophical Institute of Canterbury, 4th October, 1877.] 
Ix his address to this Institute, delivered on April 5th, 1877, Dr. von 
Haast devotes some space to the explanation of the important fact that 
rivers, whose banks are composed of loose materials, wear away their right 
banks in the northern hemisphere and their left in the southern, at the 
same time building up the opposite banks. 
Dr. von Haast gives an account of the theory of Von Baer, who first 
showed that the observed changes in the courses of rivers might be. 
explained as a consequence of the earth's rotation. Von Baer's explanation 
depends upon a well known mechanical theorem, by which the westward 
motion of the trade winds had previously been accounted for, and which 
may be thus stated—‘‘ A body moving on a meridian iends to be deflected 
towards the right in the northern hemisphere, and towards the left in the 
southern, in consequence of the change in its eastward velocity as it 
approaches or recedes from the earth's axis." The change in the eastward 
velocity, it is necessary to observe, accounts for only a part of the deflecting 
force. The direction of motion in space is also changing as the earth 
revolves. A railway truck moving on a meridian in the southern hemis- 
phere has its line of motion turned round in the same direction as that of 
the hands of a watch. There must consequently be a pressure against the 
truck towards the right, and an equal pressure against the rails towards the 
left, which must be added to that eaused by the change of eastward velocity. 
The explanation given by Von Baer does not account for the fact that 
where the course of a river is east and west the banks are worn away in the 
same manner as where the course is on a meridian. To explain this it must 
be shown that a body moving at right angles to the meridian tends to be 
deflected. 
A body resting on the earth's surface, and free to move in any direction 
upon it, is maintained in equilibrium by attraction directed towards the 
earth’s centre, and centrifugal force directed away from the axis. If the 
