280 EDITORIAL 
If anyone feels that our science is losing something of its fear- 
some interest by the decadence of faith in the nether lake of fire, 
he may find some slight consolation by turning to the growing 
list of titles of this disturbing sort: “The Gravitational Instability 
of the Earth,’’ “The Problem of Gravitational Instability,” 
“On the Vibrations and Stability of a Gravitative Planet,’ and 
“On the Dilatational Stability of the Earth.’* These themes 
open up quite a new line of inquiry relative to the central balancing 
of the earth. They imply the possibility that a symmetrical 
unstable centering of the earth’s gravity is hable to pass into 
unsymmetrical stability. There is thus brought into considera- 
tion a possible diastrophism of a profound type. We take kindly 
to this for it seems a fresh line of support to the view that diastro- 
phism may be as deep as the earth itself, a view that grows up 
naturally along with the thought of a growing earth with growing 
stresses at all stages. This view of gravitational instability may 
not be equally welcome to those who assign the earth a heart of 
gas, for if the central balance is ever unstable and becomes dis- 
turbed, the unbalanced stresses are favorable to the escape of the 
gas from its state of enormous compression and the stresses are 
withal well suited to aid in opening the way of escape. 
If we feel forced to believe that the heart of the earth is less 
fluidal than we once thought, there is now the alternative of feeling 
quite sure that it is compressible. So long as we were taught 
that the atom was an ultimate thing, impenetrably hard and 
indivisibly coherent, there was ground to feel that when a planet 
became compressed in its central parts so that the atoms touched 
one another, compression could go no farther; but now that the 
approved picture of the atom is that of minute corpuscles revolving 
in orbits at prodigious velocities, some of them now and then flying 
the track and disclosing their small sizes and great speeds, the view 
of incompressibility loses all rational basis. Compressibility of 
tA. E. H. Love, Phil. Trans. Roy. Soc. London, A, CCVII (1907), 171. 
7A. E. H. Love, Some Problems of Geodynamics, University Press, Cambridge. 
England, rort. 
3 J. H. Jeans, Phil. Trans. Roy. Soc. London, A, CCVII (1903), 157. 
4Lord Rayleigh, Proc. Roy. Soc. London, A, LUXXVII (1906). 
