Cvixgie. 19II-I9I6 — • • Errf«n u>d Terror I839-1M3 P«Bod.. 1845 



Nov.r.. IK7-U40 OiJlCTijcr. 1872 1876 Gaidlt. 1874-1876 



C>UK. 1902-1903 DiKovcry, 1902 1904 



Fig. 10. Tracks of chief vessels on which magnetic observations 

 were made In the Indian Ocean, 1839-1916 



53 



