AND OTHER WATER WAVES 121 



in gusts during that weather was frequently 

 80 s.m.p.h., ranging up to 90 s.m.p.h. in one 

 case. This was in January. 



As far as the evidence goes in this difficult part 

 of our subject, the indication is that the maximum 

 average velocity of wind maintained for I hour 

 is a few s.m.p.h. greater than the average maxi- 

 mum velocity of any long group of swells 

 originating therefrom and forming breakers upon 

 the shores of England. It is conceivable that 

 shorter groups of greater speed may owe their 

 origin to gusts, but during lulls these would be 

 running against a current of air. The maximum 

 recorded wind velocity in gusts in 1898-99 was 

 1 1 1 m.p.h. greater than that of the swiftest of 

 the short groups of swells. 



On the Connection between the Rate of Progress 

 of Cyclones and the Character of the Wares 



Strong winds in the North Atlantic are developed 

 in that part of an area of low atmospheric pressure 

 where the barometric gradient is steep. These 

 atmospheric depressions are very frequently of the 

 form and nature known as cyclones, of which the 

 general character is that shown in the accompany- 

 ig diagram. 



