SCIENCE—ADVERTISEMENTS 
Non-Euclidean 
Geometry 
A Critical and Historical Account 
of its Development 
BY 
ROBERTO BONOLA 
Authorized translation by H. 8. CAaRSLAW 
Pp. 268 Cloth, $2.00 net 
Partial Contents 
The Attempts to Prove Euclid’s Parallel Pos- 
tulate. 
The Forerunners of Non-Euclidean Geometry. 
The Founders of Non-Euclidean Geometry. 
The Later Development of Non-Euclidean 
Geometry. 
The Fundamental Principles of Statics and 
Euclid’s Postulate. 
Clifford’s Parallels and Surface. 
Clifford-Klein’s Problem. 
The Non-Euclidean Parallel Construction and 
other Allied Constructions. 
The Independence of Projective Geometry 
from Euclid’s Postulate. 
The Impossibility of Proving Euclid’s Postu- 
late. 
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