504 



In many of these instances, however, the gale force lasted for only a short time, and was in fact the 

 maximum force of the brief gusts which appear to have been a feature of every Antarctic gale. Owing to 

 their brevity they did not add much to the mileage recorded by the cup anemometer, and therefore the 

 anemometer total for the hour often fell short of the minimum of 38 miles per hour which was taken to 

 indicate a gale in the preceding table. The second set of figures may therefore be regarded as giving an 

 extreme view of the prevalence of gales, and by going a step further and assigning to each gale an average 

 duration, we may get some idea of the prevalence of gales as compared with more moderate winds and 

 calms. From an examination of the register it would appear that six hours as the average duration of 

 each gale is likely to be an over, rather than an under, estimate, and this duration would give us, very 

 nearly indeed, the same percentage of hours of gale force, as referred to the total number of observations 

 for the whole period of two years, as is given in the first of the two tables. 



The total number of hourly observations of wind in which the force exceeded a velocity of 38 miles 

 per hour at Scilly, Fleetwood, and Deerness, in the British Isles, during the same two years, 1902 to 1903, 

 was 442, 306, and 264 respectively, and these totals represent a percentage of duration of gale force to 

 that of more moderate winds of 5 per cent., 3^ per cent., and 3 per cent, respectively, so that the 

 frequency of gales appears to be greater on the western coasts of Great Britain than at Boss Island. 



The percentage of moderate to strong winds, which did not reach gale force but were logged as ranging 

 in force between 4 and 7 of Beaufort's scale, is shown in the following table : 



The direction from which gales most frequently blew was south, and this was especially the case in the 

 winter months ; but gales were also experienced from south-east, east, and north-east, and, in a few 

 instances, from south-west. North winds and winds from the west of north did not attain gale force. 



The highest recorded velocity of the wind was an average of 62 miles per hour for 12 consecutive hours 

 on July 19th, 1902. Unfortunately, there was no record of this gale made by the pressure-tube 

 anemometer, and therefore what the velocity was in the gusts cannot be known. The records of severe 

 gales in the British Islands made by pressure-tube anemometers would justify us in expecting that with so 

 high a mean velocity the gusts would not be far short of the rate of 100 miles per hour. On June 29, 

 1903, the observer was blown from the screen whilst attempting to read the thermometer, the squalls 

 being described as "furious"; and again, on August 10 of that year, the force was logged as 12 in heavy 

 squalls, and it was impossible to stand at the bottom of the gangway leading from the ship to the ice. 

 On other occasions the force in the squalls was spoken of as severe, and more than once the anemometer 

 became disabled, although, as the instrument was of somewhat slender build, too much stress must not be 

 laid upon the significance of that fact. In every gale the squalls were a very notable feature, as was also 

 the drifting snow, which occasionally quite filled the air. The low temperature and drifting snow 



