390 Scientific Intelligence. 
impelled into the northern whioe 1 are, which thus, in consequence 
e immense accumulation of warm water, has its temperature 
from the Arctic regions. When the precession of the equinoxes 
brings round the winter ablation to aphelion, the condition of 
great equatorial currents along with them. The warm water be- 
ing thus wholly withdrawn from the northern hemisphere its 
m 
"The final result to which we are, therefor os ted is thas those 
warm and cold veriods which have alternately prevailed cp 
past ages, are simply the great secular summers and winters of 
our globe, depending as truly as-the annual ones do upon ptandtiay 
‘motions, and a them also fulfilling some important ends in the 
eco eee a wit na 
es ‘of New York etc. Largé’8vo, 473 pp. New York, 1878. 
radiant ener This action is fully justified not only by the ex- 
ceptional importance just now of this department of physics, but 
also becaus ican Acade oO nd Sciences at 
Boston has recently individualized Dr, Draper’s share in its evolu- 
tion by awarding him the Rumford gold medal, and thus placing 
him on the illustrious roll of those who have e importa 
discoveries relating to light or heat ; a roll on which are the names 
of Hare, Ericsson, Treadwell, Alvan Clark, and Corliss. To par- 
ticularize individual discoveries in a book, where there are 80 
many and where all are so 
was determined and py be Ae laid for spectru analysis 
(1857, 1872); on phosphorescence and the effect of a on it 
