“pis 14, 182) 
Surely in Meteorology, as in Astronomy, the thing to 
hunt down is a cycle, and if that is not to be found in the 
temperate zone, then go to the frigid zones or the torrid 
zones to look for it, and if found, then above all things, 
and in whatever manner, lay hold of, study it, record it, 
and see what it means, If there isno cycle, then despair 
for a time if you will, but yet plant firmly your science on 
a physical basis, as Dr, Balfour Stewart long ago sug- 
gested, before, to the infinite detriment of English science, 
he left the Meteorological: Observatory at Kew; and 
having got such a basis as this, wait for results. In the 
absence of these methods, statements of what is happen- 
ing to a blackened bulb in vacuo, or its companion ex- 
posed to the sky, is, for research pene, work of the 
denth order of importance. 
I said the thing to hunt down is a cycle. Now it may 
Be asked,—Is there anywhere on earth a weather cycle? 
but anyone who asks this question will at once answer 
it himself—the question would certainly suggest the trade- 
winds and monsoons, which are short-period cycles. But 
is there anything more than this ? 
When I was preparing to go to India last year to 
observe the eclipse, Mr. Ferguson, the able editor of the 
Ceylon Observer, who happened to be in London, was 
good enough (he was good enough to us all afterwards, and 
the Eclipse Expedition of 1871 have much tothank him for) 
to give me much valuable local information about the 
time of the year at which the monsoons broke up in the 
island, Nor was this all; he added that everybody in 
Ceylon recognised a cycle of about thirteen years or soin 
the intensity of the monsoon—that the rainfall and cloudy 
weather were more intense every thirteen years or so. 
This of course set one interested in solar matters thinking, 
and I said to him, “ But are you sure the cycle recurs every 
thirteen years ; are you sure itis not every eleven years ?” 
F adding as a reason that the sun-spot period was one of 
eleven years or thereabouts, and that in the regular 
~ weather of the tropics, if anywhere, this should come out. 
This conversation Mr. Ferguson thought fit to re- 
: produce i in the Cey/on Observer,and I have now lying before 
~ me a cutting from a number of that paper I saw in India, 
(unfortunately it is cut too much, for both date and writer’s 
"mame are gone) from which I make the following extract, 
“The period is not ¢hzrteen years but eleven (as Lockyer 
states it). In the tropics, or at least, here in Ceylon, 
where we enjoy the regular changes of the two monsoons, 
5 the basic period runs five or six years dry, and five or six 
years wet. These make e/even, and they form the medium 
cycle of ¢hree—the grand cycle of thirty or thirty-three 
years—being three periods of the eleven cycles. But I 
- must premise here that though I adopt these figures as 
noting a general run of cycle, itis by no means to be 
expected that, always, these changes shall run with mathe- 
matical correctness in given grooves, for there may be 
thirteen at one time, and next Tg giving a grand 
cycle of thirty or thirty-three years.” 
It will be seen then, that those who are not professed me- 
; teorologists recognise not only the eleven-year period in 
the Ceylon rainfall, but possibly also a higher one still— 
i that of thirty-three years. In the press of work that has 
~ fallen | ‘upon me since my return to England, after my 
three n months’ absence, I have been prevented from taking 
the opinion of my meteorological friends upon this most 
important matter; but now there comes evidence on 
the question from an authority whose facts and opinions 
at once settle the matter. 
Mr. Meldrum, of the Mauritius, to whom belongs the 
honour of having established that the number of cyclones 
in the Indian Ocean and the West Indies varies with the 
sun-spot area, has lately attacked the rainfall of the 
Mauritius, Queensland, and Adelaide from the sun- 
spot period point of view, with results which are simply 
startling, although Mr. Meldrum very properly puts them 
forward to stimulate further inquiry, and not as final. 
Mr. Meldrum’s step from cyclones to rainfall is a very 
obvious one, because it is well known that cyclones are 
generally accompanied with torrential rains. The years, 
therefore, in which cyclones are most frequent should 
be more rainy than the years in which they are 
less frequent. But Mr. Meldrum remarks, in his paper 
communicated to the Meteorological Society of the 
Mauritius, “to make the rainfall a fair test of the 
existence of a periodicity of cyclones in the Indian Ocean 
it would be necessary to know the annual rainfall over the 
same area for the same length of time. If such rainfall 
had no periodicity, we should have reason to doubt a 
cyclone-periodicity ; but if there was a similar rain-peri- 
odicity, it would, so far, be a confirmation of a cyclone- 
periodicity.” 
Accordingly, as it is impossible to determine the rain- 
fall over the ocean, the law of the cyclones of which has 
been approximately determined, there remains but one 
course open, to observe the rainfall on the nearest points 
of land. This is as follows for the above-named sta- 
tions :— 
BRISBANE. ADELAIDE. PORT LOUIS. 
Years. Rainfall. Years. Rainfall Years. Rainfall 
Inches. Inches. Inches. 
1839 19'840 
1840 24107 
1841 17 956 
1842 20°318 
1843 17192 
1844 16°878 
1845 18°830 
1846 26°885 
1847 27°613 
1848 19°735 
1849 25°444 
1850 19°274 
1851 30°633 
1852 27°3 {0 
1853 -26°995 1853 39'829 
1854 153401854 39°435 
1855 23145 1855 42°665 
1856 24°921 1856 46'230 
1857 = 21156 1857 -43°445 
1858 21°522 1858 35°500 
1859 14342 1859 = 56°875 
1860 54°63 +1860 19670 1860 45°165 
1861 69°44 1861 68 733 
1862 28°27 1862 28°397 
1863 68°82 1863 33°420 
1864 47°00 1864 24147 
1865 24°11 1865 44'730 
1866 37°24. 1866 20°571 
1867 6104 1867 35970 
1868 35:98 1868 64°180 
1869 54°30 1869 = 54°575 
1870 7906 1870 45°575 
1871 45°45 1871 41610 
