SMALL WHIRLWINDS. 95 
for an altitude of seven hundred feet above sea level. During 
the month of February, I had no opportunity of observing whirls 
at times that I could note the barometrical readings, which accounts 
for that month being unrecorded on the above table. 
With this explanation, I will proceed to summarize from those 
that were practically observed. On looking over the table, and 
taking the five whirls seen on March 15th—which conjoined and 
then proceeded onwards as one left handed whirl—to represent 
one of the phenomena only, it gives a total of nine whirls which 
revolved in a right-handed direction, and ten that were left-handed. 
Although but few have been tabulated, this result gives a colour 
to my rough estimate of fifty per cent. each way, which was 
deduced from all the small whirls and eddies that I have observed 
for a long time before these special observations were made. 
Tf the “Remarks” column of my table be perused carefully, it 
it will be noted that I have marked the words “opposite currents” 
against certain whirls; at the same time the “ wind” column is 
marked as “variable.” My reason for doing so is that on 
those particular days I was so struck with the peculiar form of 
the generally small whirls observed, that I came to the conclu_ 
sion they were nothing more or less.than mere eddies. Some 
seemed to run a considerable distance along the ground before 
they were definitely formed. They dispersed immediately on 
coming in contact with a bush or tree, or any other obstruction. 
This feature led me to sub-classify them under the same heading, 
and with this object I divided them into (a) whirls formed by 
ascending currents of air, and (6) those whirls which were eddies 
produced by variable winds, or in other words, opposing currents 
of air. 
Now when two opposing currents of air meet, the stronger wind 
will control the direction in which eddies, produced thereby, 
revolve. Hence these eddies may revolve either right-handedly 
or left-handedly without causing any surprise at their apparent 
irregularity. This fact, however, does not throw any light on the 
reason for whirls, produced by ascending currents, revolving either 
