SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE. 



223" ^ 



THE 



TRANSATLANTIC LONGITUDE, 



AS DETERMINED BY THE 



COAST SURVEY EXPEDITION OF 1866. 



A REPOET 



TO THE SUPERINTENDENT OF THE 



U. S. COAST SURVEY. 



BY 



BENJAMIN APTHORP GOULD, 



LATE ASSISTANT. 



[ACCEPTED FOK PUBLICATION, FEBRUARY, 1869.] 



