102 J. F. CAMPBELL ON GLACIAL PERIODS, 
poles, nearly, if not quite, to the equator, on all meridians, like the 
shell of an egg, during successive “‘ glacial periods.” I found that I 
had, in fact, to account for some marks of polar glaciation extend- 
ing 58° from the pole in one direction. After going round Europe 
in 1873, and afterwards round the world in 1874-75, seeking marks 
of polar ice everywhere, it seemed to me that records of northern 
polar glaciation are chiefly marine and confined to the Atlantic 
basin. But I had seen cause to alter opinion so often that [ wished 
to test this conclusion in India. By climbing mountains, and by 
looking up to inaccessible peaks, I had realized the fact that an at- 
mospheric glacial climate does, in fact, surround the earth, like the 
shell of an egg, and may touch it in any latitude. By sailing about 
the ocean I realized that one cold local marine polar climate reaches 
lat. 37° at the surface; and I had learned that cold frosty climates 
underlie tropical heat in the depths of the sea, because cold water 
is heavier than hot water, till near the freezing-point*. Cold on 
the world’s surface on which we live and travel is distributed accord- 
ing to latitude. But cold is also distributed according to altitude 
in the air and to depth in the sea; and it is distributed locally at 
the sea-level by the circulation of air and sea. Dove’s isotherms 
do not coincide with circles of latitude. It seemed to me that old 
local cold climates, like those which now exist in low latitudes, 
suffice to account for all the records of glaciation that I had read 
before going to read Indian records. ‘The proved bending of the 
earth’s crust explains the transfer of a cold condensing area from 
one spot on the world to another; for the crust may have touched 
the shells of cold which are above the normal sea-level in the air, 
and below it in the deep sea, by bending upwards or downwards. 
By bending, the solid crust must have repeatedly changed the course 
of circulation in air and sea so as to change the climate at different 
places in the same latitude, at least as much as any difference that 
now exists. 
19. Any abnormal local cold climate suffices to account for any 
old record of equal cold in a like latitude after it has been proved 
that the distance between the earth’s centre and outer solid shell 
has varied locally. That is proved by marine fossils. Existing 
local cold climate about the South Pole may account for local records 
of cold in like latitudes in the northern hemisphere, because it has 
been proved by fossils that the relative position of sea and land has 
frequently changed. For example, about lat. 65° S. sea-coasts which 
now are scarcely accessible because of heavy ice may account for 
great mounds of washed glacial drift which I have seen about lat. 65° 
N.in Finland and in Northern Russia, where also recent sea-shells 
prove a recent rise in land which now is part of Northern Kurope 
and was part of a sea-bottom. Terraced countries (like Northern 
Kurope, and like hills on the Western Caspian shore along the base 
of the Caucasus), recent shells, and other marks indicate a general 
submergence of the plains of Europe. I think that submergence is 
: ; Details are given in a paper by Mr. Prestwich, which travelled with me to 
ndia. 
