468 Transactions. — Miscellancons. 



fifteen to twenty seconds : the second shock, at right angles 

 to the first, began before the first had died away, and so gave 

 to most people the impression of a tv.istiug motion ; it was 

 of undefined duration, but more marked in most of its effects 

 than the first shock. This agrees remarkabl}' ^Yith the result 

 presently arrived at. 



Bangiora. — The pendulum of the town clock vibrated in a 

 plane W. by S. to E. by N. Other clocks, at right angles to 

 this direction, also stopped. Mr. T. W. Kowe has been good 

 enough to ascertain this fact for me. 



The two movements, the normal and transverse, are clearly 

 distinguished at Greymouth, Christchurch, Kangiora — in the 

 last two places the stopping of the clocks gives a direction at 

 right angles (or nearly so) to the direction said to have been 

 noted. Most of the given chrections can be explained only 

 either on the hypothesis of error in observation, or on the 

 hypothesis that it was the transverse motion whose direction 

 was noted. Tlie transverse motion seems to have been more 

 marked everywhere ; and, even were it not so, it is natural 

 that people should mark its direction more carefully than the 

 movements taking place in the first moments of surprise. The 

 time 7.37 or 7.38 at Christchurch is on any hypothesis of the 

 origin inconsistent with the best time given, 7h. 36min. 43sec. 

 a.m.. New Zealand mean time, at Lyttelton. Most of the times 

 are approximate, being to the nearest five minutes only. 



Determination of the Origin. 



1. B/j Direction of tJie ShocJt. — By driiwing straight lines on 

 a map through the given places in the directions named, and at 

 right angles thereto in case these chrections maj' be those of 

 the transverse vibrations, we find three possible circles to cut 

 or touch a fair number of the lines drawn, within wdiich the epi- 

 centrum is to be looked for : (1.) A circle, centre A (see PI. XLL), 

 radius ten miles and a half, an epicentrum within which 

 would agree roughly with Lyell, Sheffield, Greymouth, Hoki- 

 tika, Eangiora, Waiau, and Kaiapoi (almost). (2.) A circle, 

 centre B, radius thirt}' miles, agreeing with Hokitika, Shef- 

 field, Eangiora, Christchurch, Lyell, Waiau, Greymouth. 

 Note that this circle has to be made very large to include a 

 fair number of the directions, and is not quite consistent with 

 the probable correct assumption that east to west is the direc- 

 tion of the normal wave at Greymouth. (3.) A circle, centre 

 C, radius seventeen miles and a half, agreeing with Christ- 

 church, Lyell, Sheflield, Hokitika, Waiau, Eangiora, Oxford, 

 Greymouth, Hurunui, &c. 



The circle, centre B, answers to the facts which giv^e at 

 first sight the impression of an origin near Castle Hill ; but it 

 is worthy of remark that I did not, with any combination of 



