[January 8, 1914 
530 NATURE 
Lucretius or Kapteyn? THE MAKING OF MOUNTAINS.* 
Nonne vides etiam, diversis nubila ventis diversas HE object of the very attractive volume before 
ire in partis inferna supernis? Qui minus illa queant 
per magnos ztheris orbis zstibus inter se diversis 
sidera ferri? De Rerum Naturé, v., 646-9. 
See you not too that clouds from contrary winds 
pass in contrary directions, the upper in a way con- 
trary to the lower? Why may not yon stars just as 
well be borne on through their great orbits in ether 
by currents contrary one to the other? 
Munro’s Translation. 
E: Tae 
Semi-ahsolute. 
Tue biologist, even the most mathematical, envies 
and admires the greater precision of ‘statement and 
waa 
: 
L 
Photo.) 
Fic. 1.—The Bifertenstock and Frisal, 
seen from the Firn plateau of the Tédi. 
us, as Stated by its ‘author, is to supply 
geographers with such a knowledge of geological 
processes as fs necessary for understanding the 
origin of the orographic features of the earth’s. 
surface. With this purpose in view, technical 
details are—so far as is possible—avoided, while 
disputed and doubtful topics are, as a rule, kept 
in the background; while by vivid and picturesque 
descriptions, aided by admirable photographic 
illustrations and diagrams, the reader is made 
acquainted with the chief types of mountain forms 
and the agencies by which they have been pro- 
duced. 
(Wehrli, Zitrich. 
Eocene and Mesozoic strata resting upon Gneiss. From ‘* Mountains: 
their Origin, Growth, and Decay.” 
language that is possible for the physicist, and the 
physicist in his turn is apt to plume himself on the 
fact that his sciences, as compared with those of the 
biologist, are the exact sciences. Some biologists in- 
terested in precision of terminology have been wonder- 
ing what the physicist may mean bv the term ** Semi- 
absolute ’"—a term which will be found applied to 
volts in the title of a paper recently read before the 
Royal Society (NaTuRE, December 25, 1913, P-_ 495: 
column 1). On the face of it, semi-absoluteness is no 
more easy to coneeive than is semi-infinity, and one 
is therefore tempted to regard the phrase akin to the 
“quite -all right’? of the modern young lady, the 
“quite a few” of the American, and other such 
degeneracies*of modern speech. That view must, of 
course, be wrong, but an explanation would be com- 
forting to more than one ENOUYIRER. 
NO. 2306, VOL. 92] 
The great majority of the elevations of the 
land are classed as “original or tectonic,” the 
building-up of these structures being due to many 
diverse agencies; only a smali residue of the 
relief-forms are grouped as “subsequent or relict ” 
mountains, being the result of operations that, by 
removing the surrounding materials, have left 
great upstanding masses behind. 
First among the tectonic mountains are included 
those of volcanic origin, grouped, by the author 
as .““débris cones,” which are made up of frag- 
mental materials, usually of igneous origin. but 
often accompanied by detritus from aqueous 
lz Mountains: their Origin, Growth, and Decay.” By Prof. James 
Geikie, F.R'S. Pp. xix+311-+Ixxx plates. (Edinburgh: Oliver and Boyd, 
London: Gurney and Jackson, 1913-) Price 12s. 6d. net. 
