STONE AGES OF CEYLON. EY 
in some real occurrence. It may be, as Suess maintains, 
nothing more than a traditional account of a flood in the 
lower Euphrates valley ;* but the wide diffusion of the story 
is more easily understood, if it can be shown that the catas- 
trophe which it chronicles was one affecting many countries 
of the world. 
And can it be shown that any such event was probable ? 
I think it can. My friend Mr. Charles E. P. Brooks, in a 
masterly paper read before the Royal Meteorological Society 
three years ago, showed how the influence of low temperature 
on the density of the air causes a permanent anticyclone 
to occupy the Arctic regions, and that within such regions 
precipitation must be very slight.t These conditions must 
have been very marked during the glacial period. 
Now, although the precipitation for the world at large was 
probably below normal by reason of decreased evaporation 
caused by a general lowering of temperature, the outward 
blowing winds from the anticyclone deflected by the earth’s 
rotation into a south-easterly and easterly direction allowed 
so little moisture to fall over the ice sheets that in unglaciated 
and tropical areas the annual precipitations must have been 
considerably above the normal. Evidence of a heavier 
rainfall in the past is widespread enough, for not only are 
most modern rivers too small for the valleys they occupy, but 
the great lakes, like those of Central Africa, Australia, Chad 
in the Sahara, lakes Bonneville, Lah Outan, Titicaca, and the 
lakes of Mexico in America, to mention a few, were very much 
larger in bygone days than now. 
We in Ceylon who know what a monsoon shower can do, 
and have seen hundreds of square miles inundated in a day, 
may well shudder at the thought of what the rivers really 
could accomplish if they tried. 


**“ Das Antlitz der Erde.” See English translation by Sollas, 
London, 1904, Vol. I., Chapter I. 
+ “ The Meteorological Conditions of an Ice Sheet, and their bearing 
on the Desiccation of the Globe ”? (Q. J. R. Met. Soe., Vol. XL., No. 169, 
1914, pp. 53-70). 
t Investigations show that nearly all the moisture in the Arctic 
regions falls as snow, which measured in terms of rainfall seldom 
exceeds 10 inches a year. 
6 6(8)19 
