106 H. C. RUSSELL. 
times of occurrence of some historic earthquakes and violent 
cyclones, the dates of which were authentic, with a view of ascer- - 
taining whether they supported the nineteen year weather cycle. 
The dates of the events referred to range from 1692 A.D., the 
great J amaica earthquake, to 1886 A.D. the date of the eruption 
of Tarawera. Out of the fourteen events here recorded, three 
were violent cyclones in the Bay of Bengal, unaccompanied by 
earthquakes, one a violent cyclone in the Bay of Bengal accom- 
panied by an earthquake, and the remaining eleven violent earth- 
quakes. Of the four cyclones of phenomenal violence and extent 
one was at the commencement of an “A” drought, (so called in 
Mr. Russell’s paper), one at the end of an “A” drought, one at 
the middle of a “D” drought, and one during an “E” drought. 
Of the twelve violent earthquakes, five were during or very close 
toa “D” drought, three occurred during an “ A” drought, and 
four do not appear to have been connected with any of the drought 
periods referred to by Mr. Russell. Although the evidence might 
be considered inconclusive, it appeared probable that great 
cyclones and violent earthquakes were more frequent during 
droughts than at other times. Several of them fell into the “A” 
and “D” droughts, though this does not necessarily support the 
nineteen year cycle. 
1The possible relation between droughts and earthquakes may be 
= as follows :—The earth is at present constantly radiating heat 
secular contraction results from this loss of heat, an 
pre contraction is probably the chief cause of earthquakes, through 
the earth’s crust at a depth cracking owing to excess of tension. If the 
annual temperature over the whole earth’s surface be raised, outflow of 
heat would be checked, and earthquake tion would be at a minimum. 
Conversely, if the annual temperature be lowered the escape of telluric 
neat i 
an 
Northera s Heeepnane shows that they attained their maxima in January 
and October, and their minimain June. Out of two hundred and twenty- 
three salad observed in the Southern Hemisphere the minima 
were in May and August and the maxima in November, May, June, and 
July, (as stated by Mr. J. Milne in his “ Earthquakes and other 
