PERIODICITY OF GOOD AND BAD SEASONS. 71 
The argument of my paper is, that if we take one hundred 
years of climate thoroughly studied, so that its salient features 
are clearly defined, and we compare this ‘section of time with all 
past time, so far as the data are available, and find that the 
salient points in our century are repetitions of the salient points 
in all past time, and probably in all countries, then one is justified 
in coming to the conclusion that these salient points are definitely 
connected with the climate of the world, and will appear again 
regularly in the future. The weak point is freely admitted, viz., 
that history has not kept a regular and continuous account of 
droughts, but only recorded them when they became very promin- 
ent. The strong point is that all the data that history does give 
us is in favour of the nineteen years’ cycle. 
In 1876 I read a paper before this Society o on Meteorological 
Periodicity, and pointed out that, of many cycles discussed, one 
of nineteen years seemed to represent the seasons in New South 
Wales better than any other. Since that time the subject has 
been constantly before me, and no opportunity of putting together 
facts which might be useful in the further dicussion of it has been 
lost. Scores of investigations have been carried out, some suc- 
cessful, others not so, in bringing forward evidence. My papers 
to this Society on ‘ Floods in the Darling ” and “Floods in Lake 
George,” and the careful study of the rainfall and general weather 
and the diagrams of various weather records, barometer, ther- 
mometer, wind direction and force, and rainfalls of different 
Australian latitudes, from 1840 to 1887 have all been helps. All 
the usual weather cycles have been carefully studied, one that 
very many meteorologists. accept, ‘‘ Sun Spots,” will be referred 
to later. 
And it may be explained that the word drought is not used here 
in the sense in which it is often used in England and elsewhere, 
that is, to signify a period of a few days or weeks, in which not a 
drop of rain falls, but it is used to signify a period of months or 
years during which little rain falls, and the country gets burnt 
up, grass and water disappear, crops become worthless and sheep 
and cattle die. 
