[6] In 1854, the yield was 64,661,401 tons; in 1864, the yield was 92,787,873: the average increase per annum was, therefore, no less than 2,812,647 tons.
[7] I have obtained a somewhat different result from a computation I have just gone through. I make the consumption 291 millions in 1900, and 1,446 millions in 1950. Mr. Lemoran seems to have taken the percentage at 3½ instead of 3¼. It is worth noticing how seriously a small change in the percentage affects the result; the consumption in 1950 becoming 1,760 millions of tons, instead of 1,446 millions.
[8] The year 1863 was the last whose statistics were available for Mr. Jevons’s purpose; and estimating from either 1860 or 1862 would give a result smaller than either of the above. Indeed, the consumption was less in 1862 than in 1861.
The Gulf Stream has recently attracted a large share of the attention of our men of science. The strange weather which we experienced last winter (see date of essay) has had something to do with this. The influence of the Gulf Stream upon our climate, and the special influence which it is assumed to exercise in mitigating the severity of our winters, have been so long recognised that meteorologists began to inquire what changes could be supposed to have taken place in the great current to account for so remarkable a winter as the last. But it happened also that at a meeting of the Royal Geographical Society early in the present year the very existence of the Gulf Stream was called in question, just when meteorologists were disposed to assign to it effects of unusual importance. And in the course of the discussion whether there is in truth a Gulf Stream—or rather whether our shores are visited by a current which merits such a name—a variety of interesting facts were adduced, which were either before unknown or had attracted little attention. As at a recent meeting of the same society these doubts have been renewed, I propose to examine briefly, in the first place, a few of the considerations which have been urged against the existence of a current from the Gulf of Mexico to the neighbourhood of our shores; and then, having rehabilitated the reputation of this celebrated ocean river—as I believe I shall be able to do—I shall proceed to give a brief sketch of the processes by which the current-system of the North Atlantic is set and maintained in motion.