74 THE GLACIER EPOCH OF AUSTRALASIA. 
The causes of Glacial Epochs. 
Objections to the Astronomical Theory, taken alone, as an 
adequate cause of Glacial Epochs. 
The weight of negative evidence. 
Improbability of finding evidence of intense glaciation in any 
portion of Australian lowlands among rocks of the same 
age as the Glacial Epoch of the Northern Hemisphere. 
Immunity of Australia due to latitudinal position. 
Syria and Arabia, and Northern Africa, the equivalents of 
Australia in North Latitudes. 
Estimated effect on the lowering of the névé at the time of 
the “Ice Age” in Europe. 
Calculations determining, approximately, the altitude of the 
névé for Australia and Tasmania during the Glacier 
Epoch of Australia, and the later Glacial Epoch of 
Europe and North America. 
General conclusions. 
General References to recent Literature on the subject of 
glacial action. 
INTRODUCTORY. 
The study of the geology of the globe we live in presents 
many fascinating subjects. In its Cosmical aspect we may 
confine ourselves to speculations as to its mode of origin, 
from nebular matter to the final stages which culminated in 
its specific differentiation as a subordinate among many other 
members of the Solar system; in its Geognosy we may revel 
in the nature and complexity of the combinations of elements 
which constitute its varied rocky materials; in its Geotectonie 
or Structural aspect we may enter. upon questions relating to 
the nature of and the manner in which the architecture of 
the earth’s crust has been developed, modified, or transformed ; 
in its Dynamical aspects we may inquire into the complex 
causal forces which are, or have been engaged in producing 
disturbances, movements, and changes in its physical struc- 
ture; in its Stratigraphical aspect we may devote our attention 
in tracing the chronological sequence and relationship of the 
various formations which comprise its visible crust or shell; 
in its Physiegraphical aspect we may dwell upon its surface 
feature of mountain, valley, plain, plateau, lake, cafion, river 
bed, or ocean abyss, and try to understand the causes which 
have operated in producing its sculptured form; and finally 
in its Paleontological aspect we may trace the history of the 
organic life forms whose remains are found preserved in the 
rocks, their succession or evolution, and their relationship 
to the corresponding succession of rocks. The geological 
field is thus wide and varied, and we may become so absorbed 
in the investigation of any one division of the several aspects 
