New Hypothesis of liarth-Origiii. — Faircluld. 113 
interstitial space; so does the atmosphere, condensed to soHd 
or fluid; and also the unknown but enormous amount of gas- 
eous material which has escaped from the earth's control. To 
the contraction represented by this vast amount of out-squeezed 
material must be added the condensation of the interior mass 
as absolute molecular compression without extrusion of matter. 
This latter factor in the shrinkage of the globe is the only 
one which the old hypothesis can recognize. 
The new view not only favors much greater amount of 
contraction in the globe but makes the rate of contraction more 
uniform throughout geologic time. 
To whatever degree the lateral compressive strain in the 
earth's surface layers may be due to insertion of wedges of 
igneous intrusives the new hypothesis is as favorable as the old. 
The up-and-down (epeirogenic) movements of continental 
areas are difficult of present explanation under either hypoth- 
esis. They would seem to have readier solution under the 
hypothesis which favors greater movement in the mass of the 
globe. The new hypothesis would also seem to be more 
favorable to changes produced by the invasion of the cold 
superior strata by heat from beneath. And the several possible 
requirements of viscosity or mobility, or potential fluidity of 
the interior mass are equally well met by the new hypothesis. 
With the passing of the discredited nebular hypothesis, 
substitutes should be found for the misleading terms "crust," 
"nucleus" and "igneous." 
Irregularities of the Earth's Figure. 
Although much has been written on the subject of contin- 
ental forms, and even geometric and crystallographic prin- 
ciples have been applied, yet it must be admitted that no clear 
meaning has been found for the relief forms of our globe. 
Perhaps if the efforts had not been made under a false con- 
ception of earth genesis better results might have been at- 
tained. It seems likely that the relief forms are fortuitous, due 
to irregular accretion and unequal density, and that they have 
no genetic or structural relationship. This conclusion is 
strengthened when we consider that the configuration of the 
exposed lands is greatly changed by relatively small differ- 
ences of vertical position ; and even more important, by the 
almost certair fact that the disposition and relation of lands 
