Ocean Currents

Abstract

IN reference to Mr. Laughton's letter in NATURE of the 23rd of February, I must admit that the question of the movement of barometric depressions was not introduced into my first letter, for the reason that I did not anticipate the objection of a state of equilibrium which he raised, since the average differences of pressure only were dealt with; but I do not see that it necessitates a change of ground to show how this difficulty is met by the variations which occur in the region of lower average pressure, and how these changes themselves, taking place in a certain line of movement, might affect the surface currents of the ocean; and I am not disposed to accept the sweeping rejection of the whole power of differences in the atmospheric pressure, permanent or moving, which is contained in the last paragraph of the letter referred to, until more extended observations shall show what directions the great movements of changing pressure take in passing over the parts of the ocean which lie outside of the trade wind regions.