630 
Causes,’ which was presented at the recent 
Jubilee meeting of the Society. The subject is 
treated at considerable length under the follow- 
ing heads: (1) The general causes of changes 
of temperature. (2) Geological chronology. 
The probable age of the earth. (8) The radia- 
tion of the sun nearly constant during geolog- 
ical ages. The temperature of the earth’s sur- 
face explained by the equilibrium between in- 
solation and radiation from the earth into 
space. (4) Variations in the quantity of car- 
bonie acid of the atmosphere the principal 
cause of the great climatic variations during 
geological ages. (5) The secular cooling of the 
earth is the principal cause of the variations of 
the quantity of carbonic acid in the atmos- 
phere. Modifying influences. (6) Variations of 
the obliquity of the ecliptic and their influence 
on the climate. (7) Climatic variations during 
historical times, particularly in northwestern 
Europe. Conclusions. Probable variations of 
climate in the future. R. H. Curtis considers 
‘An Improved Mounting for the Lens and Bowl 
of the Campbell-Stokes Sunshine Recorder,’ by 
means of which the glass ball can be quickly 
and accurately placed centrally in the bowl, 
where it is secured by clamping screws. W. 
H. Dines contributes a paper on the ‘ Weekly 
Death Rate and Temperature Curves, 1890- 
1899,’ which contains diagrams showing the 
death rate of the thirty-three great towns of 
England, and also curves of the temperature at 
Greenwich. The author is of opinion that from 
the health point of view the English climate is 
one of the best in the world. A pleasanter 
elimate may easily be found, but the majority 
of health resorts to which Englishmen go in the 
winter have a higher death rate than London 
has at the same season, and a far higher rate 
than any of the country districts of the British 
Isles. A paper by H. Mellish discusses ‘ The 
Seasonal Rainfall of the British Isles.’ The 
rainfall returns from 210 stations are analyzed 
for the twenty-five years, 1866-1890, and the 
percentage of the mean annual rainfall for each 
season is determined. 
THE OLD YUMA TRAIL. 
A STRIKING account of the history of ‘ The 
Old Yuma Trail’ is given by McGee in the Na- 
SCIENCE. 
[N. S. Vou. XIII. No. 329. 
tional Geographic Magazine for March. The part 
played by the arid climate of the region is 
touched upon here and there, and the terrible 
loss of life along the Trail during the ‘gold- 
fever renaissance’ is thus described : ‘‘ Many of 
the travelers were fresh from humid lands, knew 
naught of the deceptive mirage or the ever- 
hovering thirst-craze of the desert, and pressed 
out on the sand wastes without needful prepa- 
ration. The roll will never be written in full, 
since most of the unfortunates left no records, 
scores leaving no sign save some bleaching 
bones ; but observers estimate that there were 
400 victims of thirst between Altar and Yuma 
within eight years, an estimate which so con- 
servative a traveler as Capt. Gaillard thought 
fair, after he had ‘counted sixty-five graves in 
a single day’s ride of a little over 30 miles.’ ”’ 
HANN’S LEHRBUCH DER METEOROLOGIE. 
PUBLIC announcement is made of Dr. Hann’s 
forthcoming ‘Lehrbuch der Meteorologie,’ a 
book upon which, as was known to his friends, 
the eminent meteorologist has been at work for 
some time. The volume is to be published by 
Tauchnitz, of Leipzig, and may now be subscribed 
for. Itis to come out in eight successive instal- 
ments, costing 3 Marks each. Dr. Hann is so 
well known to scientific men the world over, 
through his admirable ‘ Handbuch der Klima- 
tologie’ and his many other shorter publications, 
that his new book, which is already assured a 
hearty welcome and a large sale, will be awaited 
with the greatest interest. 
NOTES. 
THE National Geographic Magazine for March 
contains a paper on ‘ The Sea Fogs of San Fran- 
cisco,’ which is an abstract of an article by A. 
G. MecAdie in the Monthly Weather Review for 
last November. Five excellent half-tones ac- 
company the paper. 
THE Bulletin of the American Geographical So- 
ciety, No. I., 1901, pp. 42-46, contains a paper 
by W. H. Alexander, Observer of the Weather 
Bureau, on ‘St. Christopher, West Indies,’ in 
which there are some statements concerning 
' the climate. 
THE full discussion of ‘The Eclipse Cyclone 
and the Diurnal Cyclone,’ by H. H. Clayton, 
