468 PIONEERS OF SCIENCE IN AMERICA. 



navigation have already received from it." While analyzing 

 and tabulating these " millions of observations," Maury wrote 

 his Physical Geography of the Sea, which took rank at once as 

 a masterly as well as a charming work. In the preface to it 

 the author attributed such success as he had achieved to the 

 observance of the rule " to keep the mind unbiased by theories 

 and speculations ; never to have any wish that an investigation 

 should result in favour of this view in preference to that; and 

 never to attempt by premature speculation to anticipate the re- 

 sults of investigations, but always to trust to the investigations 

 themselves." The book met a large demand at home and 

 abroad, more than twenty editions having been sold in Eng- 

 land alone ; and it was translated into the French, Dutch, Ital- 

 ian, Swedish, and Spanish languages. Following this came the 

 assembling of the Meteorological Congress at Brussels, in 1853, 

 of the chief nations interested in commerce, at which a uniform 

 system of observations on land and at sea was resolved upon. 

 Among the incidents of the conference was a letter in 1857 from 

 Humboldt, " at the age of ninety years," relating to its results, 

 and offering " to my illustrious friend and associate . . . the 

 tribute of my respectful admiration. ... It belongs to me, 

 more than to any traveller of the age, to congratulate my 

 illustrious friend upon the course which he has so gloriously 

 opened." 



Lieutenant Maury, after returning from the Brussels Con- 

 ference, pressed the scheme of co-operation in the meteorolog- 

 ical observations on land. In addresses delivered at agricul- 

 tural societies in 1855 he urged farmers to make daily observa- 

 tions of weather conditions and the state and yield of the 

 crops, to be sent to him, as sailors were sending their observa- 

 tions at sea ; and he advised them to seek from Congress 

 measures for the establishment of a central office where these 

 reports could be digested and the results sent monthly, weekly, 

 or even daily, to all parts of the country, so that farmers could 

 be "warned of the approach of storms, severe frosts, etc., that 

 might prove injurious to the crops." He defined this proposi- 

 tion in an address before the United States Agricultural So- 

 ciety in January, 1856, as a concerted plan, the idea of which 

 was to spread the network of instruments and observers in this 

 country and over other parts of the world also, to which he 

 was assured the co-operation of men of science abroad would 



