REVIEWS 189 
(which grew less and less) equaled the conduction from below. Then 
there was a resting time. The cracking ceased. Later thé conduction 
of heat from the interior to the crust was smaller in amount than the 
radiation from the surface. As a result lateral pressure was developed 
and caused the rise of the land above the sea here and there in folds. 
The paper then proceeds to offer proof that the conduction from 
the heated interior is vanishingly small at present compared with inso- 
lation, hence it can cause no appreciable rise in temperature now. 
There follow some paragraphs on geological time and the probable 
age of life on the earth. The author quotes some computations ‘made 
by T. Mellard Reade and communicated by Chamberlin” relative to 
the age of the sea (JOURNAL oF GrEoLoGy, Vol. VIII, p. 572). The 
computations referred to were made by Chamberlin, though this is 
not explicitly stated in the paper quoted. The estimates made by 
Nathorst, Phillips, and Geikie are given. The calculations of Lord 
Kelvin are also discussed. He is said to have made use of such 
assumptions that the results attained can hardly be regarded as any- 
thing more than a mathematical exercise without bearing on the phys- 
ical problems involved. It is maintained that there are no physical 
data disproving the high estimates of geological time favored by 
geologists and biologists. 
The headings of the third part of the paper may be rendered as 
follows: Insolation nearly constant during geological time; changes 
in the quantity of carbon dioxide in the atmosphere the principal 
cause of the great climatic changes; the cause of the change in the 
quantity of carbon dioxide in the atmosphere. The author refers to 
Lord Kelvin as having made calculations on radiation from the sun, 
and having reached the conclusion that the mean temperature of the 
sun has been constantly rising. The author has carried out further 
these computations in a paper just submitted to Kongliga Svenska 
Vetenskaps Akademien, entitled Ueber den Energie-Vorrath, die Tem- 
peratur und Strahlung der Weltkorper, and finds that the rise in the 
mean temperature of the earth has been compensated by the diminu- 
tion in the surface of the sun and also by the decreasing efficiency of 
the convection currents from the interior to the exterior of the sun. 
Possibly the radiation was less than it is now at the time when the sun’s 
radius was sixty times its present length. 
Then follows an account of the researches of Arrhenius. From 
these some conclusions are drawn. It is estimated that a diminution 
