Wellington Philosophical Society. MEI 
similar wave was observed in New Zealand, after which we had news of an earthquake in 
America, and no doubt the wave on the 11th of last May was due to a like cause. 
Dr. Hector said the tidal disturbance on the 11th of May had been observed on every 
part of the New Zealand coast, and also in Australia in the same manner; but not so 
‘correct the wave felt on our coast must have been due to a still earlier shock, perhaps 
in some other place, as it was first noticed at 5 a.m. on the 11th, corresponding to 1 p.m. 
of the 10th on the South American coast. From this date must be subtracted about 
seventeen hours for the time of the transmission of the wave across the Pacific Ocean, 
which would require that the shock should have taken place about 8 p.m. on the 9th. 
This tends to confirm the belief that there is a periodicity in earthquakes, and that they 
occur independently at distant localities at nearly the same time. He observed that a 
writer in the last received number of Nature notices this coincidence in reporting a sharp 
earthquake at Comrie, in Scotland, on the 11th of May. At Napier, where the engineer 
of the harbour works, Mr. Weber, makes exact observations, the tides were disturbed 
from the llth to the 19th. The position of Napier renders it peculiarly sensitive to 
oceanic oscillations. Thus, on the ist of May the highest tide ever experienced in Napier 
Astronomer at Sydney, which states that the slightest earth-shocks felt in New Zealand 
are nearly always recorded on the Ae 4 in Sydney and Newcastle, and are most 
unaccountably coincident with abnormal readings of one of the thermometers in the 
Observatory.* If we had well-placed tide-gauges on the New Zealand coasts it is proba! le 
the most interesting results would be obtained. Every addition to the observed facts 
bearing on this subject would be valuable. The investigation of earthquakes would be 
obscure and trivial exciting causes. 
Mr. Carruthers said he did not consider it necessary to suppose that seventeen hours 
must elapse before a tidal wave, due to the same cause as the South American earth. 
action whieh so often shows itself in a part of South America he thought was due largely 
1o the great bend made in the line of elevation of the Andes at this point, which had the 
effect of converting a deep-seated movement of the earth's crust into a violent crushing 
of the surface. 
Dr. Hector explained that the period of seventeen hours for the transmission of a 
Wave across the Pacific Ocean was derived from ol servation in 1868, when the com. 
motion of the sea extended not only to New Zealand and Australia, Lut to Japan, the 
Sandwich Islands, and the Cape of Good Hope. He agreed that earthquakes were wide- 
uA EIS ITEMS à Brg ee 
ase S -  * Trans, R. Soc. N.S.W., 1876, p. 37. 
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