100 
Now, we know, to start with, that the years of minimum 
and maximum sun-spot frequency were as follows :— 
1833, 1844, 1856, 1867 
Min. epochs oi Mette 
eas 1837, 1848, 1860, 1871 (?) 
BLA M5) 
and Mr. Meldrum has shown that these years were also 
those of minimum and maximum cyclone frequency. 
Let us begin by examining the Port Louis Observations, 
embracing nineteen years (1853-1871). 
Taking the rainfall in each minimum and maximum 
epochal year, and in one year on each side of it, Mr. Mel- 
drum gets— 
Years. Rainfall. Total Rainfall. 
Tons 2 42°665 
Min. 1850 ee) 4030 133°340 
1857. « + 43°445 
i 1859 . 56°875 
Max. 41860 . . . 45°166 170°774 
| 1361 scans 733 
1866 . 20°571 
Min. EOOY Japnuss >, £35:970 120°721 
1868 . . . 64180 
“ These figures show a marked excess of rainfall for the 
thre years comprising the maximum sun-spot year 
(1860), which was also the year of maximum cyclone 
frequency. 
“ Tf in place of one year, we take two years on each side 
of the epochs, we shall get— 
Years, Rainfall, Total Rainfall. 
SEA. oe, ustalens BOSS 
TORS: ¢ wes AzIODS 
Min. 1856 ~  « 467230 207'281 
1857 . . + 43°445 
DOSS 357500 
1858 . 357506 
1859 . 56875 
Max. J 1860 45°166 234 677 
I86E % 1) «68733 
1862s.» 20:397 
1865 . 44°730 
1866 . 20°571 
Min. 4 1867 . 33'970 220'026 
1868 . . . 64°180 
1869 . -» + 54575 
Here, again, a similar result is shown. It is not so well- 
marked as the former one, partly owing, Mr. Meldrum 
suggests, to the rain-gauge having been removed in 
1866 to a temporary Observatory, where the rainfall was 
probably somewhat greater. 
“ So far, then, as the Port Louis observations enable us 
to judge, it may be said that during the last twenty years 
there has been a rainfall-periodicity corresponding with 
the cyclone-periodicity in the Indian Ocean south of the 
Equator. 
“ This may be considered as confirmatory of the correct- 
ness of the cyclone period ; for if the rainfall a¢ one sta- 
tion shows a corresponding periodicity, much more should 
a mean of the rainfall at many stations within the whole 
cyclonic area do so.” 
Mr. Meldrum next passes on to the Australian observa- 
tions, remarking that, although Adelaide and Brisbane 
are a long way outside the area for which the cyclone 
period was determined, there also the rainfall tables seem 
to point to a similar periodicity. 
- 
Pe Se ee ee ee Se en re > ~ eh oe 
: re ey oo a. eee Se eee ea NG ever Re 
NATURE 
i 
+ 
24 ua 
(Dec. 12, 1872 > 
The Adelaide twenty-two years’ observations give: = 
Years. Rainfall, Total Rainfall. ‘ 
1843, «(5 jon pakoe 
Min. < 1844 =. ») Jaieze 52'900 
1845 .| . » %oe30 
1847 27°613 
Max. } 1848 . 19°785 72793 
1849 . 25°444 
: 1855 23°145 , 
Min. igeh aerate 24°921 69'222 ey 
TOyi7. a= aae 217156 
By taking five-year periods we get :— 
Minimum= 109076 inches. 
Maximum=118°95I_,, 
Minimum=1Io6'090_—s—=»» 
We next come to twelve years’ observations at Bris- 
bane, for which science is indebted to Mr. Edmund 
McDonnell. Comparing them with the Mauritius obser- 
vations for the same period, we cannot but be struck with 
a resemblance, which comes out still more forcibly when 
we take three-year periods, thus :— 
Years. Port Louis. Brisbane. 
1860 45166 54°53 } 
1861 68°733 7 142'296 69°44 152°34 
1862 28°397 28°27 i 
1863 33°420 68°82 
1864 24°147 ? 102'297 47°00 13993 
1865 44°730 2411 
1866 20°571 * 37°24 
1867 35°970 7 120'721 61°04 134'26 
1868 64°180 35°98 
1869 54°575 ) 54°36 
1870 45°575 ¢141'760 79°06 178°87 
1871 41010 § 45°45 
At both stations the epoch of minimum rainfall is co- 
incident, or nearly so, with the epoch of minimum 
amount of cyclones, which is itself coincident with the 
minimum amount of sun-spots ; and that at, or near, the 
maximum of sun-spots and cyclones, we have also a 
maximum amount of rainfall. 
Mr. Meldrum’s important paper concludes as follows ;— 
“ From what has been said it will, I think, be admitted that — 
at least a case of supposed periodicity of rainfall has been 
made out, and that it is highly desirable that the matter” 
should be further investigated. This can be done chiefly 
by long-continued observation under the same conditions 
as to locality, size of gauge, &c., and perhaps to some 
extent by ascertaining, if not the actual rainfall, at least 
the years remarkable for the comparative absence or — 
abundance of rain in former times. : 
“Jt should be remarked that some localities are 
probably much more favourable than others for showing 
the operation of a general law of this kind; for there 
may be local causes affecting the rainfall so powerfully 
as to completely mask the effect of a weaker but more 
general cause ; and therefore it would be no proof of the ; 
non-existence of a connection between rainfall and sun- 
spots to show that the observations taken at such and — 
such places were not in conformity with the supposed 
periodicity. : tae! 
“We should be inclined to think that the best mode of 
testing the matter would be to obtain records of obser- 
vations carefully made for a long period in some of the 
islands of the Indian and Pacific Oceans, for examples 
