Dust Whirls. 



319' 



Date. 

 Feb. 19 



Direction of 

 Rotation. 



Feb. 20 

 ,, 26 



Mar. 



AiiticJockwise 



General Reinaiks. 



A 'g-igaintic dust whirl. Described* 

 aepaxafcely below. Note. — The- 

 19th February was a typical 

 day for dust whirls, bein^ hot 

 and sultry, with a gentle N. 

 to N.W. breeze. Those record- 

 ed »ere all in the afternoon. 



Low. 



A igig'antic distant whirl. Must 

 have been hundreds, or per-- 

 haps thousands, of feet high. 

 Very dark-coloured and dense-- 

 looking. Visible for about five 

 minutes, and appeared to be 

 moving slowly southwards. The- 

 siimjnit of the column of dust 

 was clearly seeta 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. On samphire flat. 



Low. 



Low. 



Rather low. Raised much dust. . 

 Travelling northwiards. Tra- 

 velled for a ditance of a.bout. 

 half a mile while visible. 

 Direction of rotation almost: 

 certainly changed from clock- - 

 wise to anticlockwi.se, and vice- 

 versa. 



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

 occurred in the Comet Vale-Goongarrie district. 



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

 Of these 15 have no record a.s to direction of rotation, 15 are anti- 

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

 one is and twH) probably are both clockwise and anti-clockwise. 

 The anti-clockwase rotation, therefore, preduminates. This result 

 could hardly be exj^ected, 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 



