The Glacial Periods.

Kaipara and Waitemata Echo, 18 September 1914, Page 2

The Glacial Periods.

There is a growing tendency to regard glacial periods as due to variations in the atmosphere. The carbon dioxide and water ' vapour always present form a heat'etaming blanket, and a much-favour-ofTal S l b6enthat durin * t^ea much o\ J ation mid exte^°* much carbon dioxide has been ah ■orbed, while evaporation bet reduced, the natural effect bting a general lowering of tp r .„, " g a the earth's surface *mp.fatu"> °? theory hJ\ qUlte diCerent tneory has been brought m ,f i Professor W. j. Hum £ leys j n * cent volcanic explosioueJsuch^ ,s" those of Krakatoa, Pe le 2 h v ? mai-vast quantities of' fine have been projected ln £ U pp e air, and, spreading out h*x> o t f imm— ciouds° th^ s ; ei n ;: have prevented a matcH ~ of the sun's rays from ,\ . POrtio» j, , "jl^ irom reach ii-o- iu-. earth's surface. Lon.- n ?■ volcanic activity G f ™. * ? ntl,med . give a heatot^^fV' '^t that would crea :. ; u l t . dUB<--hmates. Such vole-,,; U6W -corded m tne r^\^ io^ ™* them. wni ,. h . "b' and «ne of