SEISMOLOGICAL PHENOMENA. 201 



Fisou fur the promise of his good services in this direction. 

 With his and other hel]) much more, we trust, will be done 

 thiin at first appears possible. 



3. In recording the intensity of earthquakes the Com- 

 mittee have felt the want of a common standaj'd,and we have 

 accordiugly adopted the Rossi-Forel scale as used by Italian 

 and Swiss seismologists, and (recently) in England also. 

 Though rough and variable to a slight extent, it has the 

 advantage of being a recognised standard, and is suited to the 

 nature of the evidence at our command. As it not easily 

 accessible, we append a translation of it by Mr. Charles 

 Davison, M.A., {Geological 31agazine, 1891). 



4. With regard to the determination of the origins, those 

 for New Zealand, as far as then ascertained, were given in a 

 paper read by Mr. George Hogben, M.A., at the third meeting 

 of the Association (Vol. III. — " New Zealand Earthquakes.") 

 To the " ascertained " origins there given may now be added 

 the origin of many of the earthquakes in Cook Strait. It 

 was found from the earthquake of 5th July, 1891, {see pa})cr 

 read before the Philosojthical Institute of Canterbury, 1st 

 October, 1891).* The result arrived at is confirmed in a 

 remarkable manner by the fact that the data of the earth- 

 quake of the 4th Decem})er, 1891, give an epicentrum four 

 miles N.W, of the same s])ot ; and to the same origin we 

 may reasonably assign about twenty other earthquakes felt 

 during the year 1891. It is satisfactory to note that the 

 determination of this origin has been made possible only by 

 the system of time-observations now adopted for Australasia. 

 The earthquake of the '24tli June, 1891, was one of the most 

 considerable hitherto recorded in the Auckland District. It 

 is discussed in a jjaper read by Mr. Hogben before the Philo- 

 sophical Institute of Canterbury, 4tli November, 1891. 



In a future report we may be in a position to say what has 

 been done in determining earthquake origins situated in or 

 near the other Colonies. 



While satisfactory provision has now been made for proper 

 oilicial or semi-official records, we wish to point out that 

 private individuals may largely assist the work of the Com- 

 mittee by forwarding such facts relating to earthquake 

 phenomena as fall within their notice, and we cordially 



* The t'pict'ntrum is in Cook 8trait, 65 miles from each of the places Blen- 

 heim, Masterton, and Marton — or 44 miles nearly N.N.W. of Wellington. The 

 velocity of propagation was between 15 and 18 miles per minute, probably 

 nearly 18 ; the depth of the centrum is uncertain. 



