AMERICAN PREFACE. y \\ 



phcity of exposition that is possible consistently with clear 

 and accurate representation. 



As science is now the supreme interest of civilization, and 

 roncerns alike the people of every country, and as, moreover, 

 it affords a common ground upon which men of all races, 

 tongues, faiths, and nationalities, may work together in har- 

 mony, it seemed fitting that an undertaking of this kind 

 should be of comprehensive scope and stand upon an inter- 

 national basis. With the growing sentiment of sympathy 

 and brotherhood amorg the most widely-separated students 

 of Nature, and the extensive facilities of business intercourse 

 that now exist, there appeared no reason why an interna- 

 tional combination of authors and publishers should not be 

 effected that would be equally favorable to their own private 

 interests and advantageous to the public. To gain this end 

 and guarantee to authors better remuneration for their work, 

 is a distinctive purpose of the present enterprise. But there 

 was this difficulty in the way of any such arrangement, that, 

 while the rights of foreign authors are guarded by all other 

 civilized governments, they are not protected by the gov- 

 ernment of the United States. To escape this difficulty, and 

 secure American cooperation, the first thing needed was to 

 obtain the consent of an American publishing-house to 

 grant voluntarily to foreign authors the justice which our 

 government denies them. It was agreed by Messrs. Apple- 

 ton that they would pay the foreign contributors to this 

 series the full rates of copyright that are usually allowed to 

 American authors. When this was done, engagements 

 were made with distinguished scientists of England, France, 



