PREFACE 



' I ^HE object of the author in writing this book is to 

 * exhibit views of the characters and doings of a 

 few of the world's great men of science, and the influence 

 which their work has exerted on the progress of science 

 and civilization. 



The biographical, historical, and scientific details have 

 been compiled from the best available sources ; original 

 papers, documents, and in some cases autograph letters, 

 etc., have been consulted. There is also a considerable 

 amount of original matter collected in this country and 

 abroad. 



The present volume is a " study " of a group of men 

 of science of the eighteenth and nineteenth centuries, 

 their work, and the times in which they lived. "It is 

 only by the study of what has been that we are able to 

 understand what is" and science is no exception to the 

 rule. Historical data add greatly to the interest of 

 science, and dry facts become living pictures. " By 

 following in the very footprints of the great discoverers, 

 by watching them as they make their footing sure, and 



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