AMERICAN PREFACE. ^ 



to Prof. Tyndall for his kindness in consenting to furnish 

 its commencing volume. Being prepared in a short time, 

 amid great pressure both of laboratory and literary work, it 

 contains somewhat less matter than may be expected in the 

 ensuing volumes. It treats of subjects upon which he is per< 

 haps the highest living authority; and is an admirable ex- 

 ample of that vivid, stirring, impressive style for which its 

 author is so distinguished. Prof. Tyndall is not only a mas- 

 ter in the " scientific use of the imagination," but in kindling 

 the action of that faculty in his readers. He writes in pict- 

 ures, so as to make them see what he sees. In this volume 

 he addresses himself directly to his juvenile friends, groups 

 them around him, takes them with him to his favorite moun- 

 tains, and thus adds a dramatic element and the effect of 

 personal sympathy to familiar colloquial exposition. 



The " International Scientific Sep^ies " will form an 

 elegant and valuable library of popular science, fresh in treat- 

 ment, attractive in form, strong in character, moderate in 

 price, and indispensable to all who care for the acquisition 

 of solid and serviceable knowledge ; and it is commended to 

 American readers as a help in the important work of souni] 

 public education. 



E. L. Y. 



&sw York, Sepl&nber, 1872 



