GEOLOGY OF THE INNER EARTH—GREGORY. 313 
They had that supreme gift, the power to see things as they are. 
It would not be fair to claim for them that they were the originators 
of accurate methods in geology; such methods had been used before 
their day—by William Smith in England, by Lehman in Germany, 
and by Desmarest in France. But these men, acting singly, had not 
been able to save geology from the eighteenth-century spirit of ad- 
venturous speculation, nor had they lifted from geology the burden 
of those quaint theories that made this science the butt of Voltaire’s 
luminous ridicule. 
The great achievement of the Geological Society has been this: As 
a corporate body it has been able to spread its influence very widely; 
its clear-sighted pursuit of a practical ideal has been adopted in other 
countries; its resolute rejection of the temptation to wander in dream- 
land has affected geological students all over the world. In this way 
has been laid a broad foundation of positive knowledge upon which 
modern geology has been built. 
The fine self-restraint which induced the founders of the Geological 
Society to restrict its work for a while to observing the surface of the 
earth has had its reward. The methods this society was founded to 
employ have been so widely used that we now have geological maps 
of a wider area than was known to geographers of a century ago. 
The general distribution of all the rocks on the earth’s surface has 
been discovered: most settled countries have been surveyed in some 
detail: the main outlines of the history of life on the earth have been 
written and carried back almost as far as paleontologists are likely 
to go. There are doubtless fossiliferous areas still undiscovered in 
the “ back blocks ” of the world; but, though negative predictions are 
proverbially reckless, it seems probable that paleontology will not 
carry geological history materially farther back. Fossils have been 
discovered in the pre-Cambrian rocks; the best known is the fauna 
described by Walcott from Montana; but his Beltina, the oldest well- 
characterized fossil, is still of Paleozoic type. It may be that the 
poverty of carbonate of lime, which is so characteristic a feature of 
most Cambrian and pre-Cambrian sediments, indicates that the bulk 
of the contemporary organisms had chitinous shells or were soft- 
bodied. Paleontology begins with the appearance of hard-bodied 
organisms; it can only reveal to us the dawn of skeletons, not the 
dawn of life. We are dependent for knowledge of the climate and 
geography of Eozoic time on the evidence of the sediments, of which 
there are great thicknesses beneath the fossiliferous rocks in most 
parts of the world. 
@Such are the Algonkian sediments represented by the Huronian and Algon- 
kians of America, the Algonkians of Scandinavia, the Karelian of Finland, the 
Briovarian of Northwest France, the Heathcotian of Australia, the Transvaal 
and Swaziland systems of South Africa, the Dharwar and Bijawar systems of 
India, the Itacolumnite series of Brazil, ete, 
