Proceedings of the Royal Society of Edinburgh Volume 1-60; V. 62-75 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1878 Excerpt: ...no one can doubt. If we examine a lake when the wind is blowing over it, we shall find that the plants growing in the shallow water near the surface are all bending in the direction of the wind, indicating that there is a current at the surface flowing in the direction of the wind, --the appearance of the bending plants in the lake reminding one of a slow-running river. To supply the water for this surface current there must, of course, be another current, flowing in the opposite direction underneath. The lake and the ocean are not, however, parallel cases. In the case of the lake, the wind is blowing in the same direction all over it, so that the return current is forced to flow underneath the surface, as it cannot get back any other way; whereas, in the ocean, the wind blows in one direction at one part, and in a different direction at another part, and the question now comes to be: What is the effect of the difference in the two cases? If the wind does not blow in the same direction at all parts over the surface of the water, will the return current flow underneath the surface current, or will it return by some other route? It is extremely difficult to get a satisfactory experimental answer to this question. The following attempts were, however, made: --A trough with glass sides was filled with water, the water being well stirred just before the experiment was made, to prevent difference of density due to temperature having any effect on the result. When all was again at rest, a solution of colouring matter was dropped into the water at different points. Each drop of colouring matter, as it sunk to the bottom, left a vertical coloured streak in the water. A jet of air urged by a pair of bellows was now directed along the surface of the water, so as to act .