470 Transactions. — Miscellaneous. 



second — and the earthquake, therefore, a very shght one, as 

 measured by the intensity of earthquakes in other parts of the 

 world. 



The technical assumption has been made that the epicen- 

 trum is a point ; the argument seems to show that it is not of 

 large extent ; with our data we cannot determine its size or 

 shape. F, E, D, are all within a few miles of the epicentrum, 

 as determined by Professor Hutton (Trans. N.Z. Inst., vol. 

 xxi.), of the earthquake of 1st September, 1888. It is note- 

 worthy also that the geograplheal distribution of the shock, 

 though not quite so great, is the same, as far as it goes, as the 

 distribution of that earthquake. The fact that both the 

 earthquakes that have injured the Christchurch Cathedral 

 have proceeded from the same place may be worthy of prac- 

 tical consideration in any attempts that may be made to 

 guard against possible damage in the future. 



Aet. LV. — The Origin of the Earthquake of tJte 27th De- 

 cemhcr, 1888, felt in Canterhury and Westland. 



By Geoege Hogben, M.A. 



[Read before the Fhilosopliiccd I-nstlUite of Canterhuri/, Gth November, 



2890.2 



Plate XLII. 



This earthquake was felt generally throughout Canterbury and 

 Westland, and, though it was of a slight nature, the shock or 

 shocks were so distinct, and the observations (in the absence 

 of instruments) appear to have been so accurately taken, that 

 the epicentrum can be determined with great exactness. 



The principal data are as follows : Greymouth, 9.32 p.m. ; 

 Waikari, 9.29 p.m. ; South Malvern, 9.28 p.m. ; Sheffield, 

 9.28 p.m. ; Christchurch, 9.27 p.m. ; Ashburtou, 9.27 p.m. ; 

 Dunsandel, 9.26 p.m. ; Akaroa, 9.26 p.m. (or 9.25^ p.m.). 



Inquiry made into the circumstances of these observations 

 at the time seemed to show that those at Akaroa and South 

 Malvern were the most exact. For the former I am in- 

 debted to Mr. W. Walton, then headmaster of the Akaroa 

 High School, and the two times given represent the limits 

 within which the beginning of the shock took place. That at 

 South Malvern was taken by myself. In each of these cases 

 the second as well as the minute w'as taken, and the times 

 were verified as soon as possible afterwards by New Zealand 

 mean time. They are almost certainly correct within a quarter 



