A HISTORY OF SCIENCE 



ingenuity, was a man with a deficient sense of the ethics 

 of science. He tells us in his preface that the object 

 of his book is to record some ingenious discoveries of 

 others, together with additional discoveries of his own, 

 but nowhere in the book itself does he give us the 

 slightest clew as to where the line is drawn between the 

 old and the new. Once, in discussing the weight of 

 water, he mentions the law of Archimedes regarding a 

 floating body, but this is the only case in which a scien- 

 tific principle is traced to its source or in which credit 

 is given to any one for a discovery. This is the more 

 to be regretted because Hero has discussed at some 

 length the theories involved in the treatment of his 

 subject. This reticence on the part of Hero, combined 

 with the fact that such somewhat later writers as 

 Pliny and Vitruvius do not mention Hero's name, 

 while they frequently mention the name of his master, 

 Ctesibius, has led modern critics to a somewhat scep- 

 tical attitude regarding the position of Hero as an actual 

 discoverer. 



The man who would coolly appropriate some dis- 

 coveries of others under cloak of a mere prefatorial ref- 

 erence was perhaps an expounder rather than an in- 

 novator, and had, it is shrewdly suspected, not much of 

 his own to offer. Meanwhile, it is tolerably certain that 

 Ctesibius was the discoverer of the principle of the si- 

 phon, of the forcing-pump, and of a pneumatic organ. 

 An examination of Hero's book will show that these are 

 really the chief principles involved in most of the vari- 

 ous interesting mechanisms which he describes. We 

 are constrained, then, to believe that the inventive 

 genius who was really responsible for the mechanisms 



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