348 Transactions. — Geology. 



The report of the Colonist newspaper, to which I am in- 

 debted for most of the above details, conckides that the shock 

 was more severe than that of the 19th October, 1868 : this is 

 almost certainly correct — indeed, it is the most considerable 

 earthquake felt in New Zealand since the 23rd January, 

 1855. 



The effects noted at Wellington were well marked in 

 character, but far less in degree of intensity than at Nelson. 

 The most important from the point of view of the present 

 investigation were the stopping of clocks, the ringing of bells, 

 the cracking, and in some instances the fall, of plaster, the 

 overthrow of movable objects, the cracking of some walls, 

 and the fall of a few chimneys, probably already out of re- 

 pair. 



In the Post Office buildings pendulum -clocks at right 

 angles to the line of shock (E. and W.) were stopped, and all 

 the western w^alls where the plaster of the ceiling joins the 

 wall were cracked, and chips of plaster deposited on the dado 

 moulding. It is interesting to remark that the seismometer 

 at the Museum showed a large displacement, and registered 

 movements both from east to west and from north to south — 

 that is, it showed both the longitudinal and transverse vibra- 

 tions. 



As will be seen from what follows, the velocity of propaga- 

 tion was much greater than the average velocity of New Zea- 

 land earthquakes ; and this, coupled with the undoubted fact 

 that the shock was a compound one, made the determination 

 of the origin more than usually difficult. A small error in 

 time is of far more importance with a large than with a small 

 velocity ; and when two shocks follow closely on one another, 

 and one of them only is felt at many of the places, it becomes 

 a matter of some difficulty to determine which shock it was 

 that was observed at any particular place. There is, in addi- 

 tion, the usual amount of uncertainty as to whether the same 

 phase of a long earthquake is referred to by different observers — 

 all being asked to give the time of the beginning of the shock. 

 The time put down for the apparent duration is of some 

 service in resolving this uncertainty. Using this and the other 

 means of checking the times given, I have set down the times 

 at the first five places in the list (a) as of greater weight than 

 the others. The times in this list and in the second list are 

 stated to have been all checked by New Zealand Mean Time 

 by the Telegraph officers, who filled up the forms supplied 

 to them. The times in the third list (c) were not so 

 verified. 



