INTRODUCTION. 13 



torches both of divine and human wisdom. Such 

 as these are the adventurers who, while they place 

 their own existence in jeopardy, visit the domains of 

 physical suffering, privation, and peril, either to rescue 

 others whom an unpropitious fate has there detained 

 in continual danger of destruction ; or who endure 

 the utmost extremes of all that men can undergo, 

 in order to extend the boundaries of knowledge, to 

 investigate the hidden mysteries of the globe, and 

 ascertain what portion of its treasures may yet re- 

 main unknown, which, if appropriated to the service 

 of man, might elevate his nature, might ameliorate 

 his condition, and might increase his happiness. 



We have selected the most distinguished persona 

 of this class of whom the nation can boast, as tl^- 

 subjects of the following pages; although there are 

 several others whose biographies might not unfitly 

 have been added to the list, had the limits of the 

 volume permitted. Such men are indispensably 

 necessary to the completion and fulness of a na- 

 tion's glory. They are just as requisite for that 

 purpose as profound statesmen, as able writers, as 

 sublime poets, as learned divines, as ingenious in- 

 ventors. Till such men arose to toil for the enlarge- 

 ment of human knowledge and the promotion of 

 human felicity, a lofty niche in the great Pantheon 



of the national glory remained unfilled. Those who 



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