242 JOURNAL OF SCIENCE. 



at work on the earth's crust are shown in faults, fissures, foldings, 

 cleavages, and in other ways known to geologists. The vast questions 

 here suggested are very far from being solved, and if ever they 

 are solved at all, it can only he by theories based on the widest 

 possible collection of data. It is, in short, as part of a world-system 

 of observations that our observations in New Zealand will become 

 useful. 



How is this conujction between New Zealand and the rest of the 

 world to be made ? The Australasian Association of Science has, by 

 by appointing a Seismological Committee decided to do what it can. 

 What, then, can be done ? 



Whatever is done in New Zealand should also be done for each 

 of the other Australasian Colonies, and, if possible, for the islands of 

 the Pacific, so that the general collation and comparison already 

 referred to may be made. 



The first step is for some one in each Colony to compile a list of 

 all recorded earthquakes up to the present time, including in that 

 list all the important details, as far as they are given in the records. 

 For this purpose it is necessary to search official tables, scientific 

 journals, personal narratives and the newspapers. Sir James Hector 

 has drawn up such a record for New Zealand, which I hope soon to 

 see published, and in a paper read by myself before Section A of the 

 Australasian Association, 1891, a similar list was included. In 

 gathering together the materials for the latter I asked for the 

 following particulars : — 1. Place, '2. Time, 3. Nature of Shock, 4. 

 Apparent Direction, 5. Apparent Duration, 6. Effects — other remarks, 

 7. Time-checks, 8. Authority. I asked for the omission of all 

 inferences and of unimportant details, and the replies were forwarded 

 to me, tabulated, on foolscap sheets. Nothing was to be omitted, 

 were it only the fact that a shock was felt on a certain date at a 

 certain place. 



When made, this list serves many useful purposes ; its principal 

 one is to indicate the directions in which the subsequent earthquake- 

 hunting is likely to be successful. It may show roughly the distri- 

 bution and comparative frequency of earthquake- shocks in different 

 districts, suggest positions of centres or lines of disturbance, and may 

 point to shocks in one colony synchronous or identical with shocks in 

 another more or less distant. 



The next step, which of course need not be delayed until the 

 first is completed, is to establish a uniform system of recording earth- 

 quakes as they occur. These records should be such as can be used 

 for determining earthquake origins, and as far as possible also the 

 velocity of propagation, the depth of the origin and the velocity of the 

 shock, that is the velocity of the several particles that vibrate. Good 

 time-observations are sufficient for the first two of these, and in 

 favourable instances for the third also, but for the fourth elaborate 

 instruments would be necessary — indeed, even with the best instru- 

 ments satisfactory results are rarely attainable, and doubt may still 

 be thrown upon the best observations. For the observation of the 



