562 
NATURE 
[AprIL 28, 1923 

authoritative. He adopts the views of Prof. Ellsworth 
Huntington that some great political changes in 
classical times were due to a climatic change in the 
southern part of the North Temperate zone. These 
views were discussed and rejected in a paper in the 
Geographical Journal (vol. 43, 1914, pp. 148-172, 293- 
318), and as Huntington and Visher, who quote that 
paper, say (p. 92) that in the main its “ conclusions 
seem to be well grounded,’”’ the former author has 
apparently abandoned some of the views which Mr. 
Brooks still quotes on his authority. That section of 
Mr. Brooks’s work is out of date, as is also the argu- 
ment based upon the occurrence of Galaxias in South 
America and New Zealand, since the discovery that 
this fish breeds in the sea. The main value of Mr. 
Brooks’s book depends on its meteorological chapters 
and its weighty support to the conclusion that glacia- 
tions can be explained by geographical changes. He 
omits reference to the impressive testimony on behalf 
of that theory by Lord Kelvin. 
(2) The interesting and suggestive volume by 
Messrs. Ellsworth Huntington and Visher shows an 
exceptional knowledge of the literature and contains 
an illuminating discussion of important problems on 
the borderland of meteorology, astronomy, and geology. 
They discuss Brooks’s paper in support of the geo- 
graphical explanation of glaciations, but dismiss it, 
since the distribution of ocean and continent at the 
time of the Pleistocene glaciation was much the same 
as it is now; the differences they claim were insuffi- 
cient to have produced so great a climatic change. 
They admit that changes in the positions of land and 
sea may be an important secondary agency. Differ- 
ences of opinion as to past climates are not surprising 
in face of the authors’ divergencies of statement as to 
existing geography: ‘‘ To-day the loftiest range in 
the world, the Himalayas, is almost unglaciated ”’ 
(Huntington and Visher, p. 144); ‘‘ The Himalayas, 
owing to their heavy snowfall derived from the south- 
west monsoon, bear numerous great glaciers...” 
(Brooks, p. 77). 
The authors adopt the view that climatic changes 
are due to variations in solar activity. They have 
been convinced, in spite of a prepossession to the con- 
trary, that the periodicity and seasonal variation in 
earthquake action and concurrent climatic changes 
are due to a planetary influence which also controls 
the appearance of sun-spots. They discuss the nature 
of this influence and conclude that it is not tidal but 
electrical. The effect on the earth of increased sun- 
spots is not by direct variation in temperature, since 
increased glaciation does not involve any general 
change in the earth’s temperature, which the authors 
insist has been practically uniform throughout geological 
NO. 2791, VOL. I11] 



time. Increased solar activity affects the earth by 
producing special storminess, with increased snow-fall 
in areas of high pressure and diminished rainfall and 
loess formation elsewhere. If the planets have such — 
an important though indirect effect upon the earth’s 
climate, the approach to the solar system of some of the 
greater stars must from time to time have a still more 
powerful influence on solar activity. The authors 
claim that great stars may approach the solar system 
sufficiently to stimulate intense activity in the sun, 
and thus produce glaciations on the earth at intervals - 
of time consistent with the requirements of the geologi- 
cal history of climate. 
The views on geological climates put forward by 
Messrs. Huntington and Visher appear to be generally 
well substantiated, as in their belief in the existence of 
climatic zones throughout geological time (p. 171) and 
that (p. 169) “‘ as far back as we can go in the study of 
plants, there are evidences of seasons and of relatively 
cool climates in high latitudes ” ; but their conclusions 
as to historic variations in climate are less well sup- 
ported. They attribute the English famines of 1315-16 
and 1321 to a special climatic stress due to a “‘ consider- 
able swing towards the conditions” that produce 
glaciations. In support of this view they quote 
Petterson (Quart. Jour. Meteor. Soc., vol. 38, 1912), 
that the r4th century was a period of extreme climatic 
variation, but they have overlooked Hildebrandsson’s 
reply to Petterson’s paper (Nov. Act. R. Soc. Sci., 
Uppsala (4), IV., 1915). 
Famines are so often due to an untoward con- 
catenation of many unfavourable circumstances that 
they are not a sure foundation for hypotheses of 
climatic change. Standard authorities on the _his- 
torical distribution of famine do not support the view 
that the English famines in the early part of the 14th 
century were abnormal in origin. It is even doubtful 
whether that period was especially famine-stricken. 
Dr. Farr, in his classical paper on the variation of 
wheat prices (Journ. Statist. Soc., London, IX., 1846, 
pp. 158-174), shows that famines were evenly distributed 
throughout the 11th to 16th centuries. ‘In the rth 
and 12th centuries a famine is recorded every 14 
years on an average, and the people suffered 20 years 
of famine in 200 years. In the 13th century my 
list exhibits the same proportion of famine, and nearly 
the same number of years of famine. . . . Upon the 
whole, the scarcities decrease during the three follow- 
ing centuries; but the average from 1201 to 1600 is 
the same—namely, 7 famines, and ro years of famine 
to a century. This is the law regulating scarcities in 
England.” Walford’s table of famines (Insurance 
Cyclopedia, 1874, vol. 3, pp. 165-170) shows that the 
rise in the price of wheat during the famine of 1315-16 
