liv PHYSICAL SCIENCE 



retained, though a variant might have sounded more 

 euphonious. Probably, in some cases it may be in a 

 good many the meaning has been misconceived; certainly, 

 there will be difference of opinion in regard to readings 

 adopted for translation, where one had to be taken and 

 two or more almost equally good had to be left out. 

 Ruhkopf was the text chiefly used ; in addition Koeler 

 and the Variorum Edition of Bouillet were constantly at 

 hand, and I have been much indebted to all three in 

 questions of interpretation. Nisard's French Translation 

 has also been of some service, indirectly by suggestion 

 perhaps rather than directly ; in a few passages the 

 translation is from a different text from that printed on 

 the same page. The old Tauchnitz text has been habitu- 

 ally consulted, while Gercke's text has been carefully 

 collated throughout. The latter does not mention Ruhkopf 

 at all in his Bibliography surely an involuntary omission. 

 There is a useful Bibliography also in Bouillet, but the 

 date of his Edition is as far back as 1830. To my 

 regret I have not been able to procure Lagrange's famous 

 French Translation, and the same remark applies to several 

 German works of repute. Lodge's Translation (1614) was 

 not of any service for my purpose. 



