PREFACE. 



r I ^HIS volume is made up of sketches 

 reprinted from various periodicals, and 

 coming under the general head of popular 

 science. Most of these articles have been 

 freely retouched since their original appear- 

 ance. The volume corresponds in part to 

 the first edition of " Science Sketches," pub- 

 lished in 1887. Eight of the articles are the 

 same, being printed from the same plates, 

 with a few verbal changes. For certain 

 others of the first edition, the accounts of 

 " Agassiz at Penikese," " The Fate of Icio- 

 dorum," "The Story of a Strange Land," 

 and "How the Trout came to California," 

 articles written since 1887 have been sub- 

 stituted. The author wishes to express his 

 especial obligations to Messrs. D. Appleton 



