Dmt Whirls. 



319 



Date. 



Fet). 19 



Feb. 20 

 ,, 26 



Note.- 

 occurred 



Direction of 

 ^°**"oii. General Ren.arks. 



-A gigaintic duet whirl. Described'' 

 separately below. Note. — The 

 19th February was a typical 

 day for dust whirls, beings hot ; 

 and sultry, with a gentle N. 

 to N.W. breeze. Those record- 

 ed were all in the afternoon. 



Low. 



A gigantic distant whirl. Must 

 have been hundreds, or per- 

 haps thousands, of feet high. 

 Very dark-ooloured and dense- 

 looking. Visible for about five - 

 minutes, and appeared to be 

 moving slowly southwards. The • 

 summit of the column of dust, 

 was clearly seem to be spread- - 

 ing out horizontally, as such 

 columns do. 



Low. 



Some miles distant. High, with 

 apparently a fairlv large dia- 

 meter. Travelling southwards. . 



A very high thin column. 



Low. On samphire flat. 



Low. Oin samphire flat. 



Low. 



Low. 



Rather low. Raised much dust. . 

 Travelling northwiards. Tra- 

 velled for a ditance of about 

 half a mile while visible. 

 Direction of rotation almost 

 certainly changed from clock- 

 wise to anticlockwise, and vice ■• 

 versa. 



-The dust whirls recorded from 22nd September, 1916, onwards. . 

 in the Comet Vale-Goongarrie district. 



„ 27 



Anticilockwise 



:ar. 1 





„ 1 

 „ 29 



Clockwise and 





Anticlockwise (?) 



„ 29 





„ 29 





., 29 





[ay 8 



Cflockwiise and 





Anticlockwise (?) 



Summarising the above table records a total of 43 dust whirls.. 

 Of these 15 have no record as to direction of rotation, 15 are anti- 

 clockwise, four are anti-clockwise with a query, six are clockwise, 

 one is and two probably are both clockwise and anti-clockwise. 

 The anti-clockwise rotation, therefore, predominates. This result 

 could hardly be expected, for if, as appears to be the case, the ■ 

 whirls are of the nature of small cyclones, then in the southern 

 hemispheres, the predominant rotation would be expected to follow 



