BON AIMS IMEI WO) IASI Wels, INISISUILAIR Ie PO WSUS SIS 
BY DHE RELATIONS OR MASSES PAN De ViO©MEE INGA 
In a paper entitled “A Group of Hypotheses Bearing on 
Climatic Changes,’ read before the Geological Section of the 
British Association for the Advancement of Science at the 
Toronto meeting in 1897, 1 assigned reasons for doubting the 
Laplacian hypothesis of the origin of the solar system, based on 
deductions from the kinetic theory of gases. These doubts had 
arisen in the course of certain atmospheric studies springing 
from the problem of ancient glaciation. The complete demon- 
stration by the geologists of the far Orient that extensive ice 
sheets developed on the borders of the torrid zone in India, 
Australia and South Africa during a late stage of the Paleozoic 
era had made it imperative to seriously reconsider inherited 
views relative to the nature of the earth’s early atmospheres, 
and this in turn forced an inquiry into the current postulate of a 
primitive, vast, gaseous envelope exceptionally rich in carbon 
dioxide; for the special heat-absorbing qualities of this constitu- 
ent render it doubtful whether its presence in large amount is 
compatible with glaciation. The inquiry led to the application 
of such tests as could be derived from the doctrine of molecular 
velocities. As the result of such application it appeared quite 
impossible that a hot gaseous ring formed of the matter of the 
earth and moon, and having the dimensions postulated by the 
Laplacian hypothesis, could retain its water vapor and atmos- 
pheric gases, for its gravitative control over these was found 
to be far below what was necessary to overbalance their molecu- 
lar velocities. It appeared very doubtful whether any of the 
matter of the ring, even that having the lowest molecular veloci- 
ties, could be retained at the postulated temperatures and tenu- 
ity. The test seemed altogether decisive against the Laplacian 
hypothesis if the kinetic theory be true and the computed 
tPublished in full with supplementary tables in the Jour. GEOL., Oct—Noy., 
1897, pp. 652-683. 
58 
