?94 



SCIENTIFIC NEWS. 



[April 27, 1888. 



THE HYPOTHESIS OF ADHEMAR. 



MD'ABBADIE (Ciel et Tcrre) gives a summary of 

 . the views of Adiiemar, which, he says, are at 

 least worthy of a scientific refutation, but have never 

 received it. This theory is based on a supposed period- 

 ical displacement of the earth's centre of gravity from the 

 northern to the southern hemisphere every 10,000 years, 

 followed by the transfer of the bulk of the water. Thus 

 land would alternately predominate in the northern 

 hemisphere, as we find it at present, and in the southern. 

 Adhemar maintains that our hemisphere was gradually 

 becoming warmer and warmer until the middle of the 

 thirteenth century. Since that time our climate has been 

 deteriorating, and in 10,000 years, dating from a.d. 1250, 

 the southern hemisphere will have reached a maximum 

 of warmth, and the northern its maximum of cold, 

 forming a new glacial epoch. The displacement of the 

 centre of gravity he assumes to be efiected by means of 

 the alternate accumulation of an " ice-cap " at either 

 pole, whilst it is melting away at the opposite. He 

 believes this cap to rest, not upon circumpolar land, but 

 upon the sea-bottom, and to attain a height, not of twelve 

 or twenty-four miles, as Dr. Croll surmises may possibly 

 be now the case at the South Pole, but of sixty miles. 

 Each hemisphere, according to Adhemar, is in turn 

 colder and hotter. On the warm hemisphere, where the 

 ice-cap is decreasing, the sea retires, and it gains ground 

 on the colder hemisphere, where ice is accumulating. 

 In a period of 10,000 years the conditions are reversed, 

 this reversal being attended, not incidentally, but of 

 necessity, by a universal deluge The last great catastro- 

 phe of this kind was the Noachian flood, when, according 

 to Adhemar, the great ice-cap then existing on the North 

 Pole collapsed, and the preponderating amount of water 

 which had been collected in the northern hemisphere 

 rushed across the globe to its present position in the 

 south. On this hypothesis it seems to us that the 

 southern ice-cap must continue to increase for about 

 another eight hundred years from the present date — so 

 as to make 5,000 yearp from the era of the Noachian 

 deluge — whilst the southern hemisphere becomes still 

 colder, and the sea gains ground upon the land. 



It will not escape our readers that the figures which 

 we have quoted from M. d'Abbadie lead to a different 

 conclusion. He holds that the maximum of heat for the 

 northern hemisphere and that of cold for the southern 

 hemisphere are already past, whilst if they are to fall 

 after the lapse of 5,000 years from Noah's flood, we must 

 expect them about a.d. 2652. M. d'Abbadie thinks 

 that the southern hem.isphere has grown warmer since 

 the voyages of Cook in the last century. Not long ago 

 we saw it remarked that the climate of South America 

 must be growing colder, since in the La Plata country 

 houses were formerly built without any arrangement for 

 artificial warmth, whilst now stoves and hearths are 

 becoming common. 



Returning to our summary of the views of Adhemar, 

 we find that at the expiration of a certain time, whether 

 it be A.D. 1250 or 2652, the southern ice-cap begins to 

 decrease and its northern antagonist to preponderate. The 

 maximum amount of water recedes from the southern 

 hemisphere, and encroaches upon the land in the north. 

 Finally, when 10,000 years from the time of Noah have 

 expired, and when the winter of the southern hemisphere 

 approaches perihelion, " the ice grows soft and rotten from 

 the accumulated heat, and the sea begins to eat into the 

 base of the cap, which is so undermined as to be left 



standing upon a kind of gigantic pedestal. This dis- 

 integrating process goes on until the fatal moment at 

 length arrives, when the whole mass tumbles down into 

 the sea in huge fragments, which become floating ice- 

 bergs. The attraction of the opposite ice-cap, which has 

 by this time nearly reached its maximum thickness, 

 becomes now predominant. The earth's centre of 

 gravity suddenly crosses the plane of the equator, drag- 

 ging the ocean with it, and carrying death and destruction 

 to everything on the surface of the globe." 



We need scarcely say that this theory does not har- 

 monise well with established facts in climatology, geology, 

 and animal geography. It is now found that the average 

 temperature of the southern hemisphere is not, on the 

 whole, lower, but slightly higher than that of the nor- 

 thern. As far as we can judge, the polar ice-caps rest 

 not upon the bottom of the sea, but upon land, so that 

 a rise of temperature, though it might gradually melt 

 the ice, could not bring about that sudden catastrophe 

 which the theory demands. If the caps did rest upon 

 the sea-bottom, their bases would be about the last parts 

 to be eaten into, since in all parts of the globe alike the 

 depths of the ocean have a very low temperature, little 

 above freezing-point. 



There are certainly places where the sea encroaches 

 upon the land, and others where the land gains upon the 

 sea. But such places often lie side by side, and are not 

 distributed by hemispheres. It seems probable that 

 Australia at one time extended eastwards as far as the 

 " barrier reef" But South America— at least, on the 

 western side — is rising out of the sea. The land along 

 some parts of the Baltic is sinking, and in others being 

 upraised. 



We have proof, almost, if not quite absolute, that 

 certain parts of the earth have not been submerged for 

 a length of time, even greater than this theory vi^ould 

 imply. The so-called " diluvial deposits" do not cover 

 any of the higher parts of the mountains, say, above 

 1,000 feet. The ancient Egyptians and the black races 

 of Africa have no traditions of such a deluge as is here 

 intimated. 



The distribution cf animal life appears intelligible 

 only on the supposition that on the land it has gradually 

 spread from the North Pole, whilst in the ocean it has 

 extended in the opposite direction. 



Adhemar's theory is, of course, flatly opposed to the 

 doctrine of Organic Evolution. The phenomena of life 

 are irreconcilable with a total destruction of plants- and 

 animals every few thousand years. In short, the Adhemar 

 theory may be held up as a warning to mathematicians 

 who persist in rearing up imposing— in more than one 

 sense — superstructures upon imaginarj' data. 



Services of Ants in Horticulture.— Dr. Lakonitz 

 {Humboldt) considers that ants are beneficial to trees by 

 protecting them from injurious insects and their larvce. 

 According to King, there exist, in certain plants, species 

 of Vicia, Cassia, and C. pnisses, Balsamina officinalis, 

 Hybiscus syriacus, etc., extra-floral nectaries which 

 secret sugary matter, and thus entice the ants. Lakonitz 

 even proposes to smear the stems of trees with a solution 

 of sugar so as to induce the ants to ascend them. (But 

 what of the Aphides, which ants not merely protect, but 

 even introduce into gardens and orchards, thus occasion- 

 ing great damage ? And what of the leaf-cutters ? — 

 Edit. Scientific News.) 



