I 



October i6, 1890] 



NATURE 



603 



terrestrial life, originated during the Mesozoic period, still 

 further to the southwards — that is to say, in the lost Antarctic 

 continent, for the traces of which we desire to seek. 



But it almost necessarily follows that wherever the Mammalia 

 were developed there also man had his birthplace, and if these 

 speculations should prove to have been well founded we may 

 have to shift the location of the Garden of Eden from the 

 northern to the southern hemisphere. 



1 need hardly suggest to you that possibilities such as these 

 must add greatly to our interest in the recovery of any traces of 

 this mysterious region. This land appears to have sunk beneath 

 the seas after the close of the Mesozoic. Now, the submergence 

 of any mass of land will disturb the climatic equilibrium of that 

 region, and the disappearance of an Antarctic continent would 

 prove extremely potent in varying the climate of this hemi- 

 sphere. For to-day the sun's rays fall on the South Polar regions 

 to small purpose. The unstable sea absorbs the heat, and in 

 wide and comparatively warm streams it carries off the caloric 

 to the northern hemisphere to raise its temperature at the 

 expense of ours. But when extensive land received those same 

 heat ra> s, its rigid surfaces, so to speak, tethered their caloric 

 in this hemisphere, and thus when there was no mobile current 

 to steal northwards with it, warmth could accumulate and 

 modify the climate. 



Under the inlluences of such changes the icy mantle would be 

 slowly rolled back towards the South Pole, and thus many plants 

 and animals were able to live and multiply in latitudes that to-day 

 are barren. What has undoubtedly occurred in the extreme 

 north is equally possible in the extreme south. But if it did 

 occur — if South Polar lands, now ice-bound, were then as prolific 

 of life as Disco and Spitzbergen once were— then, like Spitz- 

 bergen and Disco, the unsubmerged remnants of this continent 

 may still retain organic evidences of the fact in the shape of 

 fossil- bearing beds, and the discovery of such deposits would 

 confirm or confute such speculations as these. The key to the 

 geological problem lies within the Antarctic circle, and to find 

 it would be to recover some of the past history of the southern 

 hemisphere. There is no reason to despair of discovering such 

 evidt-nce, as Dr. M'Cormack, in his account of Russ's voyage, 

 records that portions of Victoria Land were free from snow, and 

 therefore available for investigation ; besides which their surface 

 may still support some living forms, for they cannot be colder 

 or bleaker than the peaks which rise out of the continental ice 

 of North Greenland, and these, long held to be sterile, have 

 recently disclosed the existence upon them of a rich though 

 hum' le flora. 



We have now to consider s-ome important meteorological 

 questions. If we look at the distribution of the atmo-phere 

 around the globe we shall see that it is spread unequally. It 

 forms a stratum which is deeper within the tropics than 

 about the poles and over the northern than over the southern 

 bemispht-re, so that the barometer normals fall more as we ap- 

 proach I he Antarctic than they do when we near the Arctic. 

 Maury, taking the known isobars as his guide, has calculated 

 that the mean pressure at the North Pole is 29" i, but that it is 

 only 28 at the South (Maury's " Meteorology," 259). In other 

 words, the Antarctic circle is permanently much barer of atmo- 

 sphere than any other part of the globe. Again, if we consult a 

 wind chart we shall see thai both poles are marked as calm 

 areas. Each is the dead centre of a perpetual wind vortex, but 

 the South Polar indraught is the stronger. Polarward winds 

 blow across the 45th degree of north latitude for 189 days in the 

 year, but across the 45th degree of south latitude for 209 days. 

 And while they are drawn in to the North Pole from over a 

 disk-shaped area 5500 miles in diameter, the South Polar in- 

 draught is felt throughout an area of 7000 miles across. Lastly, 

 the winds which circulate about the South Pole are more heavily 

 charged with moisture than are the winds of corresponding parts 

 of the other hemisphere. Now, the extreme degree in which 

 these three conditions — of a perpetual grand cyclone, a moist 

 atmosphere, and a low barometer — co-operate without the 

 Antarctic, ought to produce, within it, an exceptional meteoro- 

 logical state, and the point to be determined is what that con- 

 dition may be. Maury maintained that the conjunction will 

 make the climate of the South Polar area milder than that of the 

 north. His theory is that the saturated winds being drawn up 

 to great heights within the Antarctic must then be eased of their 

 moisture, and that simultaneously they must disengage vast 

 quantities of latent heat ; and it is because more heat must be 

 liberated in this manner in the South Polar re;'ions than in the 



NO. 1094, VOL. 42] 



north that he infers a less severe climate for the Antarctic. He 

 estimates that the resultant relative differences between the two 

 polar climates will be greater than that between a Canadian and 

 an English winter (Maury's "Meteorology," p. 466). Ross re- 

 ports that the South Polar summer is rather colder than that 

 of the north, but still the southern winter may be less ex- 

 treme, and so the mean temperature may be higher. If we 

 examine the weather reports logged by Antarctic voyagers, in- 

 stead of the temperature merely, the advantage still seems to rest 

 with the south. In the first place, when the voyager enters the 

 Antarctic, he sails out of a tempestuous zone into one of calms. 

 To demonstrate the truth of this statement, I have made an 

 abstract of Ross's log for the two months of January and 

 February 1841, which he spent within the Antarctic circle. 

 To enable everyone to understand it, it may be well to explain 

 that the wind force is registered in figures from o, which stands 

 for a dead calm, up to 12, which represents a hurricane. I find 

 that during these 60 days it never once blew with the force 8 — 

 that is, a fresh gale ; only twice did it blow force 7, and then 

 only for half a day each time. Force S to 6 — fresh to strong 

 breezes — is logged on 21 days. Force i to 3 — that is, gentle 

 breezes — prevailed on 34 days. The mean wind force registered 

 under the entire 60 days was 3-43 — that is, only a four to five 

 knot breeze. On 38 days, blue sky was logged. They never 

 had a single fog, and on 1 1 days only was it even misty. On 

 the other hand, snow fell almost every second day. We find 

 such entries as these — " beautifully clear weather," and "atmo- 

 sphere so extraordinarily clear that Mount Herschel, distant 90 

 miles, looked only 30 miles distant." And again, "land seen 

 120 miles distant, sky beautifully clear." Nor was -this season 

 exceptional, so far as we can tell, for Dr. M'Cormack, of the 

 Erebus, in the third year of the voyage, and after they had left 

 the Antaictic for the third and last time, enters in his diary the 

 following remark. He says: "It is a curious thing that we 

 have always met with the finest weather within the Antarctic 

 circle ; clear, cloudless sky, bright sun, light wind, and a long 

 swell" (M'Cormack's "Antarctic Voyage," vol. i. p. 345). It 

 would seem as if the stormy westerlies, so familiar to all 

 Australian visitors, had given to the v/hole southern hemi- 

 sphere a name for bad weather, which, as yet at least, has not 

 been earned by the South Polar regions. It is probable, too, 

 that the almost continuous gloom and fog of the Arctic 

 (Scoresby's " Arctic Regions," pp. 97 and 137) July and 

 August have prejudiced seamen against the Antarctic summer. 

 The true character of the climate of this region is one of 

 the problems awaiting solution. Whatever its nature may be, 

 the area is so large and so near to us that its meteorology must 

 have a dominant influence on the climate of Australia, and on 

 this fact the value of a knowledge of the weather of these parts 

 must rest. 



To turn to another branch of science, there are several ques- 

 tions relating to the earth's magnetism which require for theii 

 solution long-maintained and continuous observations within the 

 Antarctic circle. The mean or permanent distribution of the 

 world's magnetism is believed to depend upon causes acting in 

 the interior of the earth, while the periodic variations of the 

 needle probably arise from the superficial and subordinate 

 currents produced by the daily and yearly variations in the 

 temperature of the earth's surface. Other variations occur at 

 irregular intervals, and these are supposed to be due to atmo- 

 spheric electricity. All these different currents are excessively 

 frequent and powerful about the poles, and a sufficient series of 

 observations might enable physicists to differentiate the various 

 kinds of currents, and to trace them to their several sources, 

 whether internal, superficial, or meteoric. To do this properly 

 at least one land observatory should be established for a period. 

 In it the variation, dip, and intensity of the magnetic currents, 

 as well as the momentary fluctuations, of these elements, would 

 all be recorded. Fixed term days would be agreed on with the 

 observatories of Australia, of the Cape, America, and Europe, 

 and during these terms a concerted continuous watch would be 

 kept up all round the globe to determine which vibrations were 

 local and which general. 



The present exact position of the principal south magnetic 

 pole has also to be fixed, and data to be obtained from which to 

 calculate the rate of changes in the future, and the same may be 

 said of the foci of magnetic intensity and their movements. In 

 relation to this part of the subject. Captain Creak recently re- 

 ported to the British Association his conclusions in the following 

 terms. He says : — " Great advantage to the science oL 



