AMERICAN JOURNAL OF SCIENCE. 
[THIRD SERIES,] 
——_eo -—___—_ 
Art, XL.—Remarks on Professor Newcomb’s ‘‘ Rejoinder ;” 
by James Crouu, LL.D., F.R.S.* 
‘done me the honor to reply to my remarks in the October 
humber on his Review of ‘Climate and Time,’ which appeared 
'n this Journal, May, 1876. With regard to this Rejoinder of 
the views which I actually hold. I have no desire to continue 
this Controversy, but may be allowed briefly to refer to those 
Points on which I have been so thoroughly misunderstood. — 
Of course I fully concur in Professor Newcomb’s opening 
remarks as to the desirability of “a purely mathematical inves- 
hgation of the subject.” Such an investigation, however, Is, 
think, impossible at present. In a question so complex and 
difficult as that of the cause of the Glacial epoch, depending 
aS it does on the consideration of so many different elements, 
Some of which are but little understood, logical analysis rather 
than mathematics will require to be our instrument in the 
The question must first assume a clear, definite 
mean time, . 
hag logical form before mathematics can possibly be applied 
} 
Prof. Newcomb objects that my language is wanting in quan- 
: “ great, 
lative precision—that I use such terms as “g very 
* Communicated by the Author. 
_ Aw. Jour, Sct—rarep Series, Vor. XXVII, No, 161.—May, 1884, 
‘ 23 
