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direct square of the distance, and therefore the law of 
the attraction must be that of the inverse square of the 
distance. 
Mr. Arthur Wm. Waters, F.G.S., read a paper entitled 
“ Enquiries concerning a Change of Position of the Earth’s 
Axis,” in which he said that the cause of the greater warmth 
in high latitudes during the tertiary period has not, accord- 
ing to the opinion of many, yet received any satisfactory 
solution. 
The arctic Miocene flora was considered. 356 Miocene 
species have already been determined from latitude 70-77 N. 
in Spitzbergen and Greenland, and include Taxodium (swamp 
cypress of Texas), Sequoia , birch, lime, oak, beech, plane, and 
even magnolia ; so that Prof. Heer, by comparison of the 
localities of these, says that the temperature must have been 
30° F. warmer than at present. F ossil floras of the Cretaceous, 
Jurassic, and Carboniferous periods have been discovered 
within the arctic circle. Most of the plants are unable to 
resist a severe cold, besides requiring a warm summer, and 
it seems difficult to accept the fact of their flowering and 
ripening their seeds, where the winters are so long and the 
summers so short, and, apart from the lower temperature, 
where the amount of light is so much diminished. 
Several theories have been brought forward to explain 
the cold of the glacier period, the generally received one 
being that of Mr. Croll, that the glacial periods were brought 
about indirectly from an increase in the eccentricity of the 
earth’s orbit, modified by the obliquity of the eliptic. In 
the longer and colder winters more snow fell, which the 
summer could not melt away, so that the earth now covered 
gets little of the warmth of the sun. As this explanation 
has not always been thought quite satisfactory with regard 
to the greater warmth, the change of the position of the 
earth’s axis has from time to time been suggested on various 
grounds. 
