CANADIAX FISHERIES EXfEDITIOX, 191',-15 239 



itself, would be far better able to eonii)reheud the actual movement.s of the sea than 

 we are. From our point of view, the currents of the sea appear to evince an irrational 

 tendency to veer to the right; an extra-terrestrial being would, however, see in this 

 nothing but the natural effort of the water to continue its forward movement in a 

 straight line, as its inertia demands. Let us then imagine ourselves to be such beings, 

 viewing the earth from outside. We find, first of all, that the body of the planet 

 moves about its axis in the space of twenty-four hours. At the poles, the surface 

 of , the earth also moves at this rate of rotation. At the equator, the influence of 

 the earth's rotation is nil, as may be ascertained also by experiment with the 

 Foucault pendulum. In the Canadian Atlantic region, the rotation of the earth's sur- 

 face amounts, as circumstantially demonstrated in chapter 1, to about 11° per hour; 

 i.e., the Canadian waters make a full turn in something like thirty-three hours; 

 vide figs. 2 and 3. From fig. 3, also, we may see why it is that the water in more or 

 less inclosed areas circulates cyclonically. All the currents in the area tend towards 

 the right bank, and move along the same. This rule will always be found to apply 

 in high latitudes. The Gulf stream, for instance, transporting water from the tropics 

 to the Arctic ocean, keeps close to the coast of Europe, while the Polar current, 

 which carries the light Arctic water southwards, hugs the shores of Canada. The 

 result is a very marked cyclonic circulation in the North Atlantic ocean. In the 

 Xorth sea, the Skagerak, and in the Newfoundland area, the surface water every- 

 where exhibits a cyclonic circulation. 



In the lower latitudes, on the other hand, the circulation of the surface water 

 is antieyclonic, owing to the strong anticyclonic winds, and the slight effect of the 

 earth's rotation there. 



Let us now consider how this cyclonic and anticyclonic circulation would appear 

 to an extra-terrestrial observer. The earth's rotation is cyclonic; every sea-basin 

 thus also rotates cyclonically. When the water in any such basin circulates cyclonic- 

 ally in relation to the basin itself, this merely means that the rotation of the water 

 is more rapid than that of the basin. And when the water circulates anticyclonically 

 in its basin, this is in reality nothing but a cyclonic movement of the water at a 

 velocity inferior to that of the basin itself. 



It is obvious, however, that the centrifugal force of a rapidly rotating water 

 layer will be greater than that of one rotating more slowly. When, therefore, the 



Fig. 22. — Distribution of density in a sea 

 basin with cyclonic rotation of surface 

 water. 



surface water in a basin circulates cyclonically. this water will be flung radially 

 outwards, so that the separating surface between this upper layer and the one 

 immediately beneath will no longer be horizontal, but will develop a depression on 

 the coasts, and a rise in the centre of the basin, vide fig. 22. The Archimedean 

 forces thus called into play will be kept balanced by the difference between the centri- 

 fugal forcer of the two layers. 



