41 



visibilit}^ in the cold waters around the Grand Banks from May 1 1 to 

 20. (See Weather diagram, Fig. 7.) 



Fig. 9.— The distribution of atmospheric pressure May 11-17; a type of distribution that is cominon 

 during the warmer months of the year. During this period of seven days the rchitivoly cold waters 

 of the Nova Scotian and Newfoundland Banks were enveloped in thick fog. The normal fog area 

 under such conditions is shown as a shaded area on the figure 



The meteorological map for 8 a. m., May 21 recorded the first 

 material change in pressure conditions since the 11th instant. The 

 pressure increased very rapidly over the eastern half of the United 



