42 Transactions. 
confer a great benefit to the country, when we reflect on the great ad- 
vantages the Province derived from the previous elevation of land, as large 
tracts of the most valuable land were rendered available, which could 
not otherwise haye been drained without a very large expenditure of 
capital. 
Third Communication on the same Subject. 
[Read 12th October, 1868.] 
In America there appear to have been two distinet shocks of great 
magnitude, although smaller ones were felt at frequent intervals between 
the 13th and 16th, as was the case in New Zealand. The first great shock 
was experienced in:Peru at 5 p.m. on the 13th of August, which time corre- 
sponds in Wellington with 9.30 a.m. on the morning of Friday, the 14th. This 
shock is described as coming from the south and west, and there is no doubt 
that it was the result of a great submarine eruption at a considerable dis- 
tance from the coast, as within a short time it was followed by three 
ocean waves, which destroyed the towns along the coast of Peru for a dis- 
tance of 1,000 miles, between lat. 19? and 23° S. There is no reason to 
doubt that it was the westerly propagation of the same three waves the first 
of which reached New Zealand at 2.30 on the Saturday morning, having 
traversed the width of the South Pacific Ocean (over 6,000 miles) in seven- 
teen hours, giving an apparent average velocity of six miles per minute. 
This agrees with the velocity formerly calculated for the wave from the 
difference between the time at which it broke on the Chatham Islands and 
the Australian coasts. A wave having its origin a few hundred miles from 
the coast of Peru, say in lat. 25° S., as appears to have been the case in 
this instance, would reach the Australian seas by the shortest route, follow- 
ing what is termed a great circle, and would appear to reach us, not from 
the north-east, as might be expected, but from the south-east; the reason 
of which can be readily understood by examining a globe. The force which 
originated such a wave must have been tremendous, and there is no instance 
on record in history of any earthquake wave of equal extent and magnitude. 
The second calamitous event, as far as we yet know, only affected the Pro- 
vince of Ecuador, where, at 1.20 on the morning of the 16th, or at 6.10 on 
the evening of Sunday, the 16th, in Wellington, a tremendous earthquake 
shock passed slowly from east to west, devastating the districts lying 
on the western slopes of the Andes, between the Equator and lat. 5? 8. 
There is no reason to suppose that this shock, although its direction was the 
same, had any connection with the shock which was experienced in New 
Zealand on the following morning of Monday, the 17th, at 9.56; but it is 
interesting to find that at that particular period the cause which gave rise 
to earthquakes was in activity at wide distances apart on the earth’s surface, 
