238 On the Connexion between 
H.5. Chapman, Esq, is published in the 51st volume of 
the Westminster Review.. I have constructed a curve of the 
daily readings at 9 A.M. and 9 p.m., which exhibits dis- 
tinctly the great depression caused by the cyclone of the 
18th October, which is recorded as ‘‘a perfect hurricane 
from W.N.W.,” at Auckland, where the shocks were not 
felt; and “a strong 8.E. gale,” at Wellington. This de- 
pression is not due to the shocks, for these on the 18th 
were insignificant ; and no depression exists to indicate the 
occurrence of the great shocks of the 16th, 17th, and 19th. 
In accordance with this interesting fact shown by the 
curve, is the remark, that “‘ the shocks are clearly unaffected 
by the state of the atmosphere: they occur in all weathers, 
with all winds, in storms and in calms ; nor can any inference 
be drawn from the state of the barometer.” This conclusion 
is formed from the observation of many hundreds of shocks 
during a period of five years in New Zealand; and is fully 
borne out by the instances recorded during 1846, 1847, and 
1848. We are thus led to the important inference, that 
earthquakes and cyclones are concomitant, and in all proba- 
bility mutually independent, effects of volcanic action. ‘The 
earthquake travels through, or upon, the earth’s crust, and 
does not affect the barometer. ‘The cyclone travels through 
the atmosphere, and its passage over any place is invariably 
recognized by the barometer, and characterized by a sudden 
and considerable shortening of the mercurial column. 
The cyclones indicated by the minor depressions of the 
curve I have not yet sufficient data to establish. I extract 
from the journal a few meteorological remarks illustrative to 
the curve. During the first week of October the barometer 
ranged from 29°42 to 29°80, and fell slowly from the Ist 
until the evening of the 6th, when it began to: fall more 
rapidly; wind N.W. From this time until the 18th No- 
