SMALL WHIRLWINDS. id 
SMALL WHIRLWINDS. 
By Huau Cuarztes Kippis, Public School, Walbundrie, N.S.W. 
[ Read before tne Royal Society of N. S. Wales, June 7, 1893. |] 
It isa matter of common remark that numerous small whirl- 
winds are noticeable, during the summer months, in that portion 
of New South Wales which lies to the westward of the Great 
Dividing Range. These small whirlwinds, or dust whirls as they 
are commonly called, are not peculiar to Australia; they have 
been observed on the plains of India, and in other portions of the 
world during certain seasons of the year. As I am unaware 
whether meteorologists have given these phenomena a place in 
Australian “ weatherology,” further than that they exist, I submit 
the result of observations made during the months of January, 
February and March, in this Southern Riverina District. 
At first sight, and to a casual observer, these whirls seem to be: 
very erratic in their motion and appearance, light winds and 
warm weather being the only apparent requisites for their brief 
existence ; but if the whirls that are seen in this district may be 
taken as a type of those that are seen elsewhere, I conclude that 
they appear under very definite circumstances. 
The most prominent characteristics that I have observed in 
connection with these whirls are :— 
Firstly—The difference in their appearance according as the 
weather happens to be windy or calm. 
Secondly —The difference of direction in which they revolve on 
their axes. 
Thirdly—The atmospheric conditions at the time they appear. 
Fourthly—tThe effects produced on them by coming in contact 
with external bodies. 
I will deal with each of these characteristics in detail. With 
regard to the difference in their appearance, I find that these small 
