Of'tijiii (if Jloiinfciii RaiKji'x. — Reade. 275 
T invite attention to the fact that the area covered l)y these 
phenomena is broad l)Oth in longitude and hititude. and that it 
covers the Uirwer part of the territory that has been critically 
studied with reference to such determinations. This territor\- Is 
sufficient to constitute a large factor in any conclusions that can 
rationally be drawn respecting tiie attitude and altitude of the 
general area of glaciation of northeastern North America during 
the Ice age. and this area is the gi-cat area of glaciation and must 
form the central gr«^)und upon which the ultimate question of the 
cause of the glacial period, and the relationship of the altitude of 
the land to that cause, must be settled. 
AN OUTLINE OF MR. IVIELLARD RE ADE'S TH EOR Y 
OF THE ORIGIN OF MOUNTAIN-RANGES BY 
SEDIMENTARY LOADING AND CUMULA- 
TIVE RECURRENT EXPANSION. 
IN ANSWER TO RECENT CRITICISMS. 
By T. Meli.akd Reade. 
From the PhiloHophical MiKju-Ane for June, 1891. 
IXTRODITTION. 
It is now foui' years since the • 'Origin of Mountain-Ranges" 
"was written, and during that time it has ])een subjected to consid- 
erable criticism by many able men in various parts of the glol)e. 
I have purposely refrained hitherto fr<nn answering any of the 
ol)jectors to my theory, feeling that it would l)e better to wait 
and weigh them. It appears to me now that most f)f the criti- 
cisms primarily spring from an im|)erfect realization of its jjrin- 
ciples, scope, and details. 
The misconceptions no doul)t hirgely arise from the complex 
nature of the problems and the difiiculty of keeping the various 
threads of the argument unravelled. I'nder these circumstances, 
T have thought lluit tlic best ri'ply I can make is to restate in a 
shorter manner the various salient points of my theory. Prob- 
ably, if T had given the theory a name, and properly christened 
my Itantling liefore sending it forth in the world to seek its for- 
tunes, I might have been saved from paternal difficulties. 
To prevent further misconceptions. 1 now name my theory the 
"Origin of Mountain-Ranges by Seilimentary Loading :ind Cumu- 
lative Recurrent Kximnsion. " 
