70 Preliminary Remarks 



America (and vice versa). I have listed the edition available to me 

 which was sometimes the English, edition, sometimes the American. 

 When the place quoted is New York or Boston, the experienced reader 

 knows that it might as well be London. 



Sometimes the same book has different titles in the English and 

 American editions. The fact has been mentioned whenever I was aware 

 of it. 



Some authors will entitle their book, say "The history of biology." 

 Others seem to think that it is more modest to phrase the title "A history 

 of biology." Either article is superfluous and it has generally been left 

 out. It is quite enough to write "History of biology." 



I have tried to give an idea of the size of each item, because it makes 

 a great difference to the student whether an item covers a hundred pages 

 or a thousand, but it suffices to indicate that size grosso modo. E.g., if 

 a book has iv + 256 p. it is simply stated 260 p. That indication is but 

 an approximation. For what matters is the length (or capacity) of a 

 book, and that length is very incompletely measured by the number of 

 pages. 



4) It was tempting to add critical remarks to each item, and thus to 

 help the reader to select one book among twenty devoted, say, to the 

 history of physics. It was not possible to indulge that temptation to any 

 extent, because it is very difficult to compare twenty books dealing with 

 the same subject, without unfairness. To begin with, they seldom deal 

 with the self-same subject. Even when their subject is defined by the 

 same title "History of mathematics," the areas covered by each author 

 are not the same; they may overlap considerably but are never identical. 



The author has examined almost every book listed by him, but he 

 did not examine them at the same time. He may have read the one 

 thirty years ago and the other yesterday; under those conditions it is 

 clear that comparisons between them would be adventurous and un- 

 reliable. The best that he could do was to refer to reviews or shorter 

 notices in Isis, whenever possible. References to the Critical Bibliog- 

 raphies of Isis have the additional advantage of bringing the reader in 

 touch not only with the item he is particularly interested in but also with 

 many others. It is like hunting for a book in a library where the books 

 are well classified by subjects: sometimes one does not find the book one 

 is hunting for, but one may find a better one, that is, one better adapted 

 to his immediate purpose. 



5) The choice of books dealing with a large subject, say, the history 

 of mathematics is difficult, because the best books generally do not deal 

 with the whole subject but only with a part of it, and because the sub- 

 ject may be (and is actually) divided and subdivided in many ways 

 which do not tally. For example, one book is devoted to the history of 

 trigonometry, another to the history of mathematics in Germany, a third 

 one to the history of algebra in Italy, a fourth to the history of trigo- 

 nometry in the sixteenth century, a fifth to the history of reckoning in 

 England during the Middle Ages. 



Some books are too special to be listed; yet, those books may be the 



