DARWIN AND WALLACE 25 



charts of all the seas. Frequently she has sent out 

 great charting expeditions to various parts of the 

 world. One of these was to go out in Her Majesty's 

 ship, Beagle, for a voyage around the world. Captain 

 Fitzroy was in command, and he was especially com- 

 missioned to map the coast of South America from 

 La Plata to Cape Horn and up the western side. In 

 addition to this work, by carrying a set of accurate 

 chronometers, he was to check up the longitude of 

 the various ports to be visited in this circumnaviga- 

 tion of the globe. It was customary on such expe- 

 ditions to carry a young man whose duty it was to 

 study the natural history of the countries visited on 

 the trip. The salary of such a naturalist was so small 

 that an experienced man could scarcely afford to take 

 the place. Therefore the appointment usually went to 

 a man rather of promise than of achievement. 

 Through Henslow's influence, Charles Darwin was 

 offered this position in 1831. Darwin hastened to ob- 

 tain his father's permission, but the elder Darwin at 

 first declined to consider the matter. He felt that his 

 son had not made such use of his time at the univer- 

 sity as warranted the hope that much could be ex- 

 pected of such a journey. He believed it necessary 

 that Charles should have some means of earning an 

 adequate living before he could think of devoting his 

 time to science. Charles found an efficient advocate 



