to invite Belgium, Denmark, France, Great Britain, Holland, Nor- 

 way, Portugal, Russia, and Sweden to send representatives to a 

 meeting in Brussels to discuss a universal system of observations 

 at sea. It was the first international meteorological conference ever 

 to be held. 



Two years later Britain's Board of Trade started a meteorological 

 department under Admiral Fitzroy, and by 1857 about two hundred 

 merchant ships had been fitted out with instruments. Among the 

 inducements offered to shipowners'^was a promise of free copies 

 of all charts and books resulting from the work. They were to 

 contain information about wind, ocean currents, and the surest and 

 quickest sea routes. 



Today's charts compiled in Britain, Germany, Holland, Japan, 

 the United States, and U.S.S.R. are about as good as charts showing 

 average conditions can be. They divide the ocean into small squares, 

 and then all the information available for each square over the past 



Average current conditions are sliown on 

 "current roses." Ttie ocean is divided into 

 squares and ttien all the information 

 available for each square over past 

 years is sorted into months and 

 averaged over each square for each month. 

 In some squares a single direction is 

 predominant, suggesting a prevailing 

 current, but in others there are two or 

 more favored directions, suggesting a 

 variable current. This chart is for the 

 North Pacific and clearly shows the east- 

 ward-flowing Kuro Shio Current. (Compare 

 with the currents chart on pages 204-05.) 



150 years is sorted into months and averaged over each square for 

 each month. The resulting summaries are generally shown as "cur- 

 rent roses," compasslike diagrams showing what percentage of all 

 the measurements fall in each direction. In some squares a single 

 direction is predominant, suggesting a prevailing current; in others 

 two or more favored directions show a moderate range of variabil- 

 ity. But in others there is so much variation that the current cannot 

 be said to favor any particular direction. Even strongly prevailing 

 currents can vary a good deal from day to day. In addition, there are 

 many regions of variable current where the navigator would like 

 to know how his ship is likely to be influenced by local and general 

 meteorological conditions prevailing at the time. Here is another 

 of the many ways in which oceanographers can help merchant 

 shipping. 



The whole problem of currents is too complex to be solved 



The Arctic Ocean is divided into two basins, 

 each about 13,000 feet deep, by a region 

 of more complicated topography that 

 incorporates the Lomonosov Ridge. 

 It is surrounded by the large, shallow shelf- 

 seas north of Europe, Asia, and America. 



185 



