i 9 o SCIENCE PROGRESS 



taken by the Archivio (ibid. 84-6). There is also a useful set 

 of bibliographical and other notes (ibid. 76-83) on Leonardo 

 da Vinci. The appearance of this new journal is a very wel- 

 come sign of the movement towards a systematic study of the 

 history of science, which has occupied so much of our thoughts 

 during recent years, chiefly owing to the work of Sarton and 

 others (cf. Science Progress, 1919, 14, 2). 



G. A. Miller (Math. Gaz., 191 8, 9, 247) draws attention to 

 an error arising from Gow's mistranslation of the German 

 " Ruthen " which was used by Eisenlohr to translate an Egyp- 

 tian word for a measure of length. Gow uses " ruths," while 

 the Egyptian word was entirely different, and seems to have 

 denoted certain pieces of wood. Thus it would seem natural 

 to translate into English by " rods," which is the equivalent 

 of " Ruthen " ; and " Ruthen " was perhaps used by Eisenlohr 

 in a non-mathematical sense — since the length of this measure 

 has not come down to us — just as our word " rods " is com- 

 monly used in a non-mathematical sense. The error men- 

 tioned has infected other books. 



L. M. Klinkenberg (49-50) continues and ends his papers 

 (cf. Science Progress, 191 9, 13, 521) on ancient Greek geo- 

 metry. J. A. Schouten (50) gives the first part of an address 

 on modern geometry and algebra. M. Lecat (52) published in 

 1 91 6 a bibliography of the calculus of variations from its 

 beginnings up to 1850. 



A posthumous article, which is to serve as an introduction 

 to the book on Descartes Savant (cf. Science Progress, 191 9, 

 14, 4), by Gaston Milhaud (Rev. de. Metaphys, 1919, 26, 297-31 1), 

 justifies in detail the belief of the author in the essential sin- 

 cerity of Descartes ; the accusations of plagiarism which have 

 so often been made against Descartes are explained by the 

 " lesson which results with some clearness from the history of 

 sciences, that there is a kind of current which dominates more 

 or less individual researches at the same time, and which leads 

 men of science to the same truths." 



F. Klein, M. Brendel and L. Schlesinger (52) published in 

 191 8 the sixth part, by Ph. Maennchen, of their collection of 

 materials for a scientific biography of Gauss (cf. Science Pro- 

 gress, 1919, 13, 522). 



Biographies of Darboux (cf. ibid. 346) have been written 

 by M. d'Arsonval and A. Lacroix (38) and E. Picard (38). An 



