BOOK NOTICES. 641 
Where Did Life Begin ? Sy G. Hilton Scribnef. tamo,, pp. 64. Chas. 
Scribner's Sons, New York, 1883. $1-25. 
This is an inquiry as to the probable place of beginning and the natural 
causes of migration therefrom of the flora and fauna of the earth. The author's 
ordinary business duties are alleged by him to have been sufficient employment 
without engaging in scientific work, but having followed out certain lines of 
thought to their logical conclusions in his own judgment and submitted them to 
his friends, he was persuaded to pubhsh them. 
Assuming that the earth was at one time a fiery mass, the first question 
asked is "what part or parts of its surface first became sufficiently cooled by 
radiation to be habitable by plants and animals?" Inasmuch as the heat of the 
Sun upon the earth has always ofiFsetted the heat radiated from the earth, to a 
certain extent, and this offsetting has been much less in degree at the poles than 
at the equator, necessarily the region about the poles cooled off and became 
habitable first. Besides this, the polar regions had less matter to cool, and radiated 
heat into space more rapidly in proportion to mass than any other portion of the 
earth's surface; consequently it seems evident that the polar regions necessarily 
passed through the different temperatures, climates and climatic conditions now 
characteristic of the various zones, before any other portion of the earth became 
habitable, and were actually adapted to all the requirements of animal and vege- 
table life before them. It is next assumed that life did actually commence within 
one or both of certain zones surrounding the poles and sufficiently removed 
from them to receive the least amount of sunlight necessary for animal and vege- 
table existence. Then the lowering temperature and its accompaniments crept 
slowly downward from the Arctic, through the temperate, to the torrid zone, 
and the differing forms of life kept pace, abandoning the polar region as its heat 
was reduced below the living point, and occupying the other zones by turns. 
Having thus stated his premises and conclusions, the author proceeds to 
support them by the topographical condition of the earth's surface, the currents 
of the ocean, the movements of the winds, the fossil remains of animals and 
plants found in the polar regions, etc. His points are well made and carry con- 
nection with them. The work is logical throughout and attractively written. 
Electricity in Theory and Practice : By Lieutenant Bradley A. Fiske, U. 
S. N. Octavo, pp. 270. Illustrated. D. VanNostrand, New York, 1883. 
$2.50. 
To any student who desires a work lucidly explaining both the theory and 
practical applications of electricity, we can offer nothing better than this. As 
Lieut. Fiske says, many practical men and students have found great difficulty 
in seeing the relation between the theory of electricity and its practical applica- 
tions "because they have had to study the theory from books devoted wholly 
to abstruse theory and the practical applications from books devoted wholly to 
the practical applications." His object has been to furnish a book showing the 
