56 MATTHEW FONTAINE MAURY 



and the force and direction of the latter at different 

 seasons of the year. The Trade Wind Charts gave the 

 limits, extent, and general characteristics of the trade 

 wind regions, together with their neighboring zones of 

 calms. The Pilot Charts showed in every square of 

 fifteen degrees the direction of the wind for sixteen points 

 of the compass that would probably be found in that 

 square during each month of the year, the results being 

 based upon the number of times the wind was reported 

 to have been from that direction in former years. The 

 Thermal Charts recorded the temperature of the surface 

 of the ocean wherever and whenever it had been ob- 

 served, the different temperatures being distinguished 

 by colors and symbols in such a manner that mere in- 

 spection of the chart showed the temperature for any 

 month. The Storm and Rain Charts demonstrated in 

 every square of five degrees the number of observations 

 that had been made for each month, the number of days 

 in which there had been rain, a calm, fog, lightning and 

 thunder, or a storm and the quarter from which it had 

 blown. The Whale Charts, finally, showed where 

 whales were most hunted, in what years and months 

 they had been most frequently found, whether in shoals 

 or as stragglers, and whether sperm or right whales. 



Though the cooperation which Maury enjoyed was an 

 extensive one, he was still not satisfied, and as early as 

 1851 he conceived the idea of a universal system of 

 meteorological observations on both land and sea. 

 Through the advice of British scientists, he decided to 

 confine his system, for the time being, only to the sea, 

 though he was afterwards to regret such a curtailment 

 of his original scheme. With the authority of Secretary 

 of the Navy William A. Graham, to whom Maury was 



