118 E. T. Quayle : 



probable, I think. As regards the three winter months — May r 

 June and July — the smallness of the latitudinal temperature 

 gradient, aided by the more rapid cooling of continental areas r 

 enables even the most ordinary type of Antarctic disturbance to 

 bring rain as far inland as the Murray River, and in summer 

 thunderstorm tendencies over the Mallee will be greater with the 

 alternation of ploughed fields and narrow timber belt than they 

 would be with the uniformity of Mallee scrub, and its tendency 

 to cool the lower levels of the atmosphere. The experience of 

 aviators tends to confirm this last. 



That the gain in this case was not confined to the spring months 

 is evident by the following tables, showing the mean annual 

 totals : — 



1885-94. 1895-04. 1905-14. 



Swan Hill 15.15 .. 11.20 .. 12.28 



Tyrrell Downs 15.91 .. 10.36 .. 11.45 



Kerang 16.76 .. 11.71 .. 14.13 



Means 15.94 '. . 11.09 '.. 12.62 



1885-94. 1895-04. 1905-14. 



Charlton 18.59 .. 14.01 .. 16.55 



Marmal 17.16 .. 12.16 .. 14.06 



Wychitella 16.56 .. 12.66 .. 16.23 



Means 17.44 '. . 12.94 '. . 14.95 



Calling the first 1885-94 group mean A, and the second 1885- 

 94 group mean B, the other means may be expressed as per- 

 centages of these as follows : — 



A, .69 A, and .79 A, and B, .74 B. and .86 B. 



These show relative gains of B over A of 5 per cent., and' 

 7 per cent., or actual annual gains of about 0.9 and 1.2 inches. 



It may be added that, in the selection of stations, no attempt 

 was made to pick, and choose. The first selection was the one 

 used. Kerang is not, however, quite as well situated as the others 

 for the purposes of this investigation, but it was the only other 

 Victorian outpost station with long enough record. The results 

 from two others might have been given. Waitchie, about mid- 

 way between Tyrrell Downs and Swan Hill only goes back to- 

 1893, but well supports the former, and Murray Downs, which 

 is on the New South Wales side of the Murray, supports Swan 

 Hill. 



Substituting these for Kerang, we get the following results r . 

 which quite support the spring difference between the two rain- 

 fall groups, and indicate an even greater annual difference. The- 



