MICHIGAN ACADEMY OF SCIENCE. 
1H 
the low temperatures of space to freeze the errant water into plane- 
tessimals of ice. Hydrogen and oxygen might, for all we know to the 
contrary, come separately to the earth's atmosphere to he here combined. 
Water, liquid water, does constantly traverse space, see our own hydro- 
sphere, held by the gravity of a planetary mass. V enus is supposed to 
be bathed in oceans. Comets may contain water in some form. Cosmic 
water must certainly receive some consideration. 
The indications are strongly to the effect that prior to the end of the 
Glacial Epoch the earth possessed less water than it has had since, 
even allowing liberally for any amount that may have been locked up on 
the land in the form of ice. And the coming of water in sufficient 
quantity is surely capable of explaining the phenomena of the close of 
glaciation, the Champlain depression and the Terrace reelevation, just 
as the preceding lowness of sea-level is capable of explaining the fact of 
glaciation itself and the many land-connections which floral and faunal 
distributions demand. It thus becomes an eligible working hypothesis 
for a number of related problems. 
It would not be reasonable to deny that other factors may have very 
materially influenced the same phenomena. Local movements, orogenic 
and epeirogenic, still have to be reckoned with ; variations of orbital 
eccentricity, changes of ocean currents and other influences may yet 
be invoked to account for particular features. Other glaciations have 
come and gone in the course of geologic time and whether or not their 
causes were the same as those of the Pleistocene we may not positively 
sa}’. Some of the influences considered in the foregoing analysis seem 
to be recognizable by their effects even though they are held to be 
inadequate for the main explanation. Underneath all else there is the 
persistent suggestion of some deeper, grander cause and it is that with 
which we should attempt to grapple. 
The natural reference of these problems of altitude is to correlation, 
but insofar as correlation is to be based, as Chamberlin would have it, 
upon diastropliism, which in turn contemplates the relative altitudes of 
land and sea, it would seem that the groups of facts bearing upon these 
broad questions should be viewed collectively and that general conclu- 
sions should not be unduly hampered by preconceived ideas of correla- 
tion in particular localities. 
Pending further discussion we may sum up the conclusions thus far 
obtained as follows : 
1. During an undetermined period prior to the close of the Pleisto- 
cene Glacial Epoch there was a much lower ocean-level than there has 
been since. 
2. At the end of that epoch there was an increase in the volume of 
the oceans so that the general level rose several thousand feet, probably 
a mile or more. 
3. In the present state of science it is impossible to account for this 
increase of the ocean on the basis of the previous existence of the excess 
on or about the earth. 
4. A natural inference is that the increase resulted from cosmic 
causes which, for the purposes of the present paper, may be left in 
general terms. 
