104 H. C. RUSSELL. 
communication to the Sydney Herald, expresses his opinion that 
Sturts’ desert, Leichhardt’s experience of little or no rain even in 
the tropics, Sir T. L. Mitchell’s sufferings on the Bogan from want 
of water, and the state of the Colony generally, prove this to have 
been a year of drought parallel with the season of 1826-7, and 
certainly adding another link to the chain of facts for establishing 
an atmospheric cycle of nineteen years.” 
Prof. THRELFALL said:—Mr. Russell’s statement as to what 
constituted a good or a bad season is somewhat indeterminate. 
(1) An exact definition of the difference between a drought and 
a good season was essential, otherwise there must bea fundamental 
uncertainty in the investigation. A farmer or pastoralist may be 
supposed to do well or ill according to a variety of circumstances, 
amongst which rainfall is no doubt a prominent but not over- 
powering factor. 
(2) The records of Australia have, as I understand, only been 
kept with anything like adequate care for about five and twenty 
years, while the period decided on by Mr. Russell is nineteen 
years. Hence the observations have not really extended over 
more than a period and a third, and this is rather too little to 
form a foundation for such a wide generalization. Before the 
records were kept properly, the evidence as to ‘good’ and ‘bad’ 
years may have involved other than meteorological factors. 
(3) With regard to the historical evidence advanced in which 
droughts are cited sometimes from Europe, sometimes from India, 
leaves it uncertain whether there is a drought somewhere every 
nineteen years, or whether droughts recur at the same place every 
nineteen years. 
(4) The statement in the paper, that Egypt like Europe seems 
to get its change of weather a year earlier or later than Australia, 
should appear in the historical evidence as drawn indifferently 
from Europe and India and run on the Australian records. 
(5) These criticisms apply to droughts of the A series only. 
The evidence for the other series is on Mr. Russell’s own shewing 
not sufficient to establish any periodicity at all. 
