xx TRANSLATOR'S INTRODUCTION. 



He says, p. 490: "Tentamina idcirco quae 

 olim feceram, breviter exponenda veniunt; ne 

 saltern alius quis operam eandem perdat." He 

 anticipates J. Delboeuf's * ' Prolegomenes phil- 

 osophiques de la geometric et solution des 

 postulats," with the full consciousness in 

 addition that it is not the solution, that the 

 final solution has crowned not his own intense 

 efforts, but the genius of his son. 



This son's Appendix which makes all pre- 

 ceding space only a special case, only a species 

 under a genus, and so requiring a descriptive 

 adjective, Euclidean, this wonderful produc- 

 tion of pure genius, this strange Hungarian 

 flower, was saved for the world after more 

 than thirty-five years of oblivion, by the rare 

 erudition of Professor Richard Baltzer of 

 Dresden, afterward professor in the Univer- 

 sity of Giessen. He it was who first did jus- 

 tice publicly to the works of I^obachevski 

 and Bolyai. 



Incited by Baltzer, in 1866 J. Ho li el issued 

 a French translation of Lobachevski's Theory 

 of Parallels, and in a note to his Preface says: 

 "M. Richard Baltzer, dans la seconde edition 

 de ses excellents Elements de Geometric, a, le 

 premier, introduit ces notions exactes a la 

 place qu'elles doivent occuper,' : Honor to 



