Perry.] 148 [March 6, 
sion and suggestion. Points have been considered in the best light 
at command. No statement has been made to stop investigation; 
each utterance has been put forth with a view to rouse honest in- 
quiry; to lead each to question his positions; to get help myself, and 
to aid our younger geologists generally to find out on just what ground 
they stand. We cannot honestly adopt conclusions simply as such, ~ 
but only as the legitimate outflow of premises, which as put to the 
test prove themselves valid. We are to endorse superstructures 
solely as we see the underlying foundation, and so see it as to get 
substantial evidence that it is able to support them. It is only as 
this is done, that there can be an adequate guarantee of real pro- 
gress, of a healthy growth, of a living advance, which will constantly 
lead into closer and more intimate sympathy with nature in her vital 
processes. If what has been written shall aid in this direction; in 
case it leads the author of the, in many respects, excellent pamphlet 
under review, to re-examine his positions, and establish himself on 
a more substantial, and therefore on a more trustworthy basis; should 
it help those who are engaged, or such as may be hereafter enlisted, 
in geologic studies, to a deeper insight of the truth as it is in nature, 
and as it has been revealing itself from age to age in the history of 
the globe, the aim of the writer will be fully accomplished. 
March 6, 1872. 
The President in the chair. Twenty-one persons present. 
Dr. Kneeland read the following extracts from letters 
written by Mr. John Muir, on the winter phenomena of the 
Yosemite Valley. 
On the cold, south, or eclipsed side of valley, average from January 
1 to 24, 1872, at Black’s Hotel: 
Average morning temperature . : . : . ._ 820 Fahr. 
noon : : : 5 : . : 40° 5 
Maximum morning “ : 5 : : : : 36° 
ie noon 5 - “ é A z 52° 
Minimum morning “ : : : - 220° 
‘ noon se : : ° . " : 32° 
Mild and delightful weather, wholly unlike the stormy December, 
with a little rain and snow, but mostly sunshine. 
