489 



owing to the exigences of sledging the hours of observation were more or less irregular; and there WM 

 also the added difficulty of having to determine the wind direction without instrumental aid. On some 

 of these points the information given in the Journal is less complete than could be desired, and fuller 

 information respecting what was done in correcting the observations for the magnetic variation would 

 have been especially useful. This last point is, of course, one of much importance, and, unfortunately, it is 

 one respecting which little that is definite is said in the note books. 



Dealing broadly with the observations, the most prominent feature of the wind which they reveal is the 

 frequency with which light variable airs and calms occurred. Most of the journeys were made between 

 the beginning of October and the end of January, and at Winter Quarters in those months calms were 

 recorded in approximately 25 per cent, of the observations ; but upon the whole their occurrence appears 

 to have been much more common to the southward and westward of the ship, approaching 40 per cent, in 

 the former direction and upwards of 50 per cent, in the latter. At the same time the gusty character of 

 the wind is maintained by the observations, and occasionally the squalls were very sharp and severe. 



From the observations made in the course of the journeys to the south and west, it would appear that 

 in those directions the wind was more southerly than it was at Winter Quarters, but the uncertainty 

 which exists respecting the correction of the records for magnetic variation makes it inexpedient to speak 

 very definitely upon the point. On some of the western journeys, however, a considerable altitude was 

 attained, certainly above 7000 feet, and the observations of the movements of the lower clouds made at 

 the ship would lead us to expect at that height above the sea a southerly, or even a westerly, current such 

 as is recorded in the logs. 



Also it should be remembered that the southern journeys followed the line of lofty mountains which, 

 stretching away to the southward, form the eastern boundary of Victoria Land ; and it is quite conceivable 

 that an easterly wind current sweeping across the Barrier would, on meeting this range, become deflected 

 to the northward and would in consequence be felt by the sledging parties as a southerly or even a south- 

 westerly wind. 



One of the most important journeys considered with reference to the observations of wind direction was 

 that of Lieutenant EOYDS, to a distance of 170 miles to the south-east across the Great Ice Barrier, made 

 in November, 1903. Throughout this journey the party was far removed from any land, and there were 

 absolutely no obstructions to the free movement of the air in any direction ; and therefore the observations 

 of wind direction should be valuable in relation to those made simultaneously at the ship. If we could 

 ,assume that the observations were made by compass and entered in the note-book as made, without 

 correction, we get, after applying a mean correction for variation, the following analysis of the 



observations : 



i per cent. 



Observations of N. by E. (true) 4 



N.E. N. ( ) 15 



N.E. E. ( ) 5 



E. N. ( ) 51 



Calms 25 



100 



If the assumption that the observations were not originally corrected for compass error is a correct one, 

 the confirmation these results afford to the accuracy of the distribution of winds obtained from the 

 observations made at the ship would be very great, more especially because of the very open character of 

 the region in which the observations were made. 



On the other hand, if we suppose the observations to have been corrected for variation before their 

 entry in the log, we find ourselves confronted with a problem it is not easy to solve : How are we to 

 account for the existence of a steady south-westerly current within a few miles of the ship, whilst at Cape 

 Armitage and at the ship herself, although quite open and unsheltered towards the south-west, easterly 

 winds were experienced almost exclusively, a south-west wind being of extremely rare occurrence, and a 

 westerly wind practically never felt at all ? 



3 R 



