• TRANSACTIONS OF SECTION A, 41 



sions. The shocks there are accordingly strictly local, or do 

 not extend farther than Taupo at most. In fact, we know from 

 other parts of the earth that earthquakes connected with vol- 

 canoes are often local in character. 



III. Earthquake-origins in New Zealand. 



G is a table showing the origins of disturbance, so far as 

 they have been worked out, under four divisions : — 



(1) Ascertained — in which the degree of accuracy is as great 



as it can be in the absence of instruments. 



(2) Approximate — in which the epicentrum found agrees 



with the data, but can be only roughly determined. 



(3) Probable : the epicentrum found agrees with the mass 



of the data, but is inconsistent with some ; or the 

 data are not sufficient in number for certainty or 

 exactness. 



(4) Doubtful : the evidence inclines to the region shown, 



but leaves room for doubt. 



Ln this table I have also given the depth of the centrum 

 and the velocity of propagation (where possible) . 



H is a map of New Zealand with the epicentra or epicen- 

 tric areas marked upon it, and classified as in Table G. 



I is a sketch-map on a reduced scale to show the same 

 origins. (PL III.) 



The epicentrum of the earthquake of the 1st September, 

 1888, was determined by Professor Hutton, who has also 

 pointed out, in the case of the series of shocks at Wellington 

 on the 23rd January, 1855, and following days, that, in- 

 asmuch as part of the ground at Wellington itself was 

 raised 4ft. or 5ft., the epicentric area must have included 

 Wellington. 



The remaining earthquake-origins, thirty-four in number, 

 have been determined by myself, three of them forming the 

 subjects of papers read iDefore the Philosophical Institute of 

 Canterbury during the past year : time-methods have been 

 used for the most part, other methods being only auxiliary. 



The epicentra, as will be seen at once, fall into several 

 groups, most of which are on or near the line drawn through 

 White Island, Tarawera, Taupo, Tongariro, Ruapehu, D'Urville 

 Island, Queenstown. Between Lakes Sumner and Christabel 

 is the epicentrum of the great earthquake on the 1st Septem- 

 ber, 1888, which brought down the spire of the Christchurch 

 Cathedral, and also of the earthquake of the 5th December, 

 1881, which did a slighter injury to the same structure. To the 

 same region I refer five other earthquakes, and there are others 

 that might very reasonably be- assigned to it. Most of the 



