VOLUME ONE OF THE NEOMONIC SERIES. 



NICOLAI IVANOVICH LOBACHEVSKI. 



BY A. VASIL.IEV. 



Translated from the Russian by 



GEORGE BRUCE HALSTED. 



From a six-column Review of this Translation in Science, March 



29, 1895: 



"Non-Euclidian Geometry, a subject which has not only revo- 

 lutionized geometrical science, but has attracted the attention of 

 physicists, psychologists and philosophers." 



"Without question the best and most authentic source of infor- 

 mation on this original thinker." 



From a two-column Review in the Nation, April 4, 1895, by C. 8. 



Pierce: 



"Kazfin was not the milieu for a man of genius, especially not 

 for so profound a genius as that of Lobachevski." 



"All of Lobachevski's writings are marked by the same high- 

 strung logic." 



I have read it with intense interest. By issuing this transla- 

 tion you have put American readers under renewed obligation to 

 you. FLORIAN CAJORI. 



I have read with great interest your translation of the address 

 in commemoration of Lobachevski. It is a most fortunate thing 

 for us in the rank and file that you have maintained such an in- 

 terest in the history of this non-Euclidian work; for while you 

 have conquered for Saccheri, Bolyai and the rest the share of 

 fame that is their due, you have made it impossible for American 

 teachers of any spirit to shut their eyes to the " hypothesis anguli 

 acuti." Very truly yours, 



G. H. LOUD, 

 Professor of Mathematics in Colorado College. 



BURLINGTON, VT., October 19th, 1894. 

 I am astonished to find these researches of such deep,, philo- 



