AUGUST 13, 1914] 
NATURE 
617 
carpentry, and metalwork,” “practical courses on 
marine motors and their installation, net-mending 
and the preservation and curing of fish,” and 
‘business methods’ all in continuation evening 
classes? Surely these are not school subjects, but 
handicrafts, and surely the attempt to teach them 
in schools is merely overloading a primary educa- 
tion already burdened by sufficient imperfectly 
taught ‘“‘subjects.” If these things are to be 
really useful they must be acquired by a boy in 
the daily practice of his occupation. 
If scientific instruction can be given in addition 
to the above, so much the better, say the inshore 
committee.. It is proposed that this instruction be 
given by “‘occasional lectures.” These would ex- 
plain “the most up-to-date methods as well as the 
cogency of the case for any newly imposed by- 
laws.” They would “obviate any resentment felt 
for ordinances” and “convince fishermen of their 
expediency.” Would they? The experience of 
the Lancashire local committee, which first in 
England attempted to regulate, by restrictions, a 
large inshore fishing population was that any 
attempt to argue for (or explain) by-laws by © 
means of public lecture was. fatal at once. . But 
simply to impart, by means of sound: laboratory 
instruction, the main things in the life-histories 
of marine economic animals—that is, by pure 
scientific instruction—has gradually effaced the 
intense hostility to legislative interference which 
those who began fishery regulation in England 
experienced. This end has to be attained in- 
directly. It is like the much-discussed question 
of sex-hygiene instruction. Why not. plainly 
teach human physiology? And must one still 
apologise in England when he wishes to impart a 
scientific education ? 
Certainly methods of preservation, curing, 
marketing, etc., ought to be described in lectures 
and informal conferences; certainly methods of 
fishing in use abroad or in other parts of the 
country should be demonstrated; certainly the 
choice and upkeep of motor installations should be 
the subject of informal meetings and conversa- 
tions, all these things being described to inshore 
fishermen by “practical’’ men or tradespeople. 
But this is rather organising the industry than 
educating the fishermen. Tee f- 
SECULAR CLIMATIC CHANGES IN 
AMERICA? 
NES the meteorologist nor the geologist 
commonly realises the extent and import- 
ance of the changes which have taken place dur- 
ing the “historic period.” The latter is apt to 
close his investigations with the Ice Age; the 
former too often concerns himself only with the 
period of instrumental observations. The inter- 
vening “post-Glacial”’ time is the field of rela- 
tively few workers, who are rapidly building up 
the new science of “ Palzeoclimatology.” 
Prof. Huntington’s elaborate memoir on the 
1 “The Climatic Factor as Illustrated in Arid America.” By Ellsworth 
Huntington, with contributions by Charles Schuchert, Andrew E. Douglass, 
and Charles J. Kullmer. Publication of the Carnegie Institution of Wash- 
ington, No. 192, Pp. v+341. (1914.) 
NO. 2337, VOL. 93] 
“Climatic Factor ” should do much to gain recog- 
nition for at least the later stages of this period. 
From the viewpoint of the “pulsation” theory 
of climates developed during similar investigations 
in arid Asia, the author studies the climates and 
their attendant effects during the last thirty-five 
centuries over an area extending from California 
to Guatemala. A study of the ruins of arid New 
Mexico shows that at three distinct periods prior 
to the coming of the Spaniards the country was 
able to support a far greater population than can 
exist at present; this could only have been pos- 
sible with a heavier rainfall, permitting the culti- 
vation of regions now too dry for agriculture. The 
strand lines and gypsum dunes of the Otero Soda 
Lake and the alluvial terraces of the rivers point 
to the same conclusicn (though the theory that 
even in rivers reaching the sea terraces and deltas 
are the result of changes of climate rather than of 
level will come as a shock to most English geolo- 
gists). 
In America there are no continuous historical 
records from which the ruins can be dated; this 
deficiency is supplied in an unexpected way by the 
measurement of the rings. of. growth of. the giant 
Sequoias of California, some of which are more | 
than three thousand years old. By means of an 
empirical formula, Prof. Douglass, in a chapter on 
a method of estimating rainfall by the growth of 
trees, has been able to reconstruct the rainfall, for 
the period over which records exist, with an accu- 
racy of 82 per cent. With the very .old trees, 
however, a number of corrections are necessary, | 
which render uncertain the slope of the curve - 
plotted from the measurements, although they do 
not impair the evidence of short-period fluctua- 
tions. The corrected curve shows cycles of 155 
years, of -21°0 .years,..and. of 114. years, and in 
addition three long wet periods, from 1000 B.c. to 
300 A.D., from goo to 1100 A.D., and from 1300 to 
1400 A.D., which Prof. Huntington considers must 
correspond to the three native civilisations of New 
Mexico. 
This curve is next compared with the curve 
previously published in ‘ Palestine and its Trans- 
formations,’ showing the fluctuations of climate 
in arid Asia. There is a pronounced agreement 
between the two curves, especially during the 
period from 300 to 1000 A.D. 
The Maya civilisations of Yucatan and Central 
America are next investigated—though, since these 
regions largely suffer from an excess of precipita- 
tion, they can scarcely be included in “arid” 
America—and the theory is developed that these 
extinct civilisations fell in dry, cool periods con- 
temporaneous with the moist periods of New 
Mexico, both changes being the result of a south- 
ward movement of the subtropical anticyclone. 
The coolness stimulated the Mayan races into ac- 
tivity, and the dryness enabled them to master the 
forest. The dates of the Maya chronology are 
| not yet satisfactorily worked out, but so far as 
they go they confirm this correlation. An attempt 
is made to connect the terrestrial changes with 
changes of the sun’s surface, but the results, 
| which are illustrated by curves, do not appear to 
