ARCTOWSKI'S PLEIONS 493 



however,^ we find the same periodicity as in the regions fartlier soutli, but 

 with a lag- of about a year. This is what would be expected in a i-egion 

 wliose climate depends largely on tlie monsoons. These winds, as is well 

 known, drive the waters of the southern Indian Ocean up into the Ara- 

 bian Sea. They thus eventually bring to Boml)ay the heat which was 

 originally accumulated in the broad oceanic regions farther south. Under 

 such circumstances we should naturally expect that if the torrid zone 

 were unusually warm at a certain period, no matter wliat might be the 

 cause, the heat would be carried northward in such a way that the warm- 

 est time at Bombay would be later than in the more oceanic regions to 

 the south, and thus we should get an apparent contradiction. Arctow- 

 ski's work shows that similar contradictions are found elsewhere, in such 

 regions as the West Indies and the neighboring coasts of Florida, where 

 the influence of oceanic currents is particularly strong. In Europe, where 

 the general type of climate is dominantly under the influence of winds 

 which have been warmed ])y the waters of the Gulf Stream and its con- 

 tinuation in the Atlantic Drift, we should expect a still greater degree of 

 lagging. If the torrid zone w^ere warm during one particular year, the 

 effect of that would presumably be felt in course of time in Europe. How 

 great the delay would be we can not tell. N"ansen^* has shown that 

 'S'ariations in the temperature of the Atlantic Current off the Norwegian 

 coast from one year to another seem to be succeeded two years later by 

 similar variations in the quantity of ice in the Barents Sea in the spring." 

 This means that in this far northern region the heat wliich the Atlantic 

 Drift and tlie Gulf Stream have brought in varying quantities from the 

 torrid zone is carried along at the rate of much less than a thousand miles 

 a year. In its earlier course the heat is carried faster; but as it travels 

 from 7,000 to 10,000 miles, several years must be consumed in the jour- 

 ney. Under such circumstances it is clear that in Europe, where the 

 subject has been most carefully investigated, we should fully expect that 

 the conditions of temperature would be quite different from those of the 

 torrid zone. Such a difference would neither prove nor disprove a pos- 

 sible relation between sun-spots and climate. This conclusion, if well 

 grounded, removes one of the chief objections to the solar hypothesis. 



Cyclonic storm f^ vntliin the tropics.- — Having seen that, so far as tem- 

 perature is concerned, there seems to be no good reason why we should 

 not accept the solar hypothesis and many good reasons why we should, 

 let us turn to some of the other climatic elements. The winds, as we 

 have already seen, are by far the most important determiner of tempera- 

 ture, aside from the sun itself. In their investigation attention has been 



"F. Nansen : The sea route to Siberia. Geographical Journal, vol, 43, 1914, p, 492. 

 XXXVI — Bull. Gbol. Soc. Am., Vol. 25, 1913 



