828 Essays. 
COMPARISONS WITH THE SOUTH ISLAND. 
Tt is a point worthy of note that the vertical oscillations of the two great 
islands of New Zealand seem to have differed very much, both in time of 
occurrence and in degree. In the North Island the depression in tertia 
times would appear to haye been much greater than that of the South Island. 
At all events, if not greater in amount, it must have affected the character of 
the island to a greater degree, from its much smaller elevation and conse- 
quent greater submergence. 
; In the North Island the greatest depression seems to have been on the 
western side, while in the South Island the reverse was probably the case. 
In the North Island the tertiaries occupy a far greater area than in the 
South Island, which alone would tend to show a longer and greater 
depression. Glacial action must have had much less effect in the North 
than in the South Island, irrespective of difference of latitude ; for two peaks 
only in the former island now carry perpetual snow, viz. Ruapehu and 
Mount Egmont, and at no tertiary time could the mountain masses have 
equalled those of the latter island. 
AEROLITES. 
Aerolites have been frequently seen in New Zealand. It is believed, 
however, that the only one which has been found on the surface of the 
country is that which will be now described. It was found inthe year 1863, 
in front of Mr. Donald’s house, at Manaia, near the left bank of the Wai- 
ngawa River, in the Wairarapa, Province of Wellington. The plain is here 
composed of coarse gravel. The aerolite was found on or near the surface, 
and measures 9 in. by 6 in. by 7 in. 
A portion of this interesting specimen was forwarded for examination to 
the Laboratory of the Otago Geological Survey, at Dunedin, and the follow- 
ing notes respecting its composition have been furnished by Dr. Hector:— . 
“The fragment submitted for analysis was externally of a rust colour with 
an exudation of chloride of iron. The freshly fractured surface was of a 
dull grey colour. Its hardness was between 5 and 6, and its specific gravity 
9254. It is affected by the magnet, but does not exhibit polarity. It con- 
sists principally of earthy silicates and sulphide of iron, but also contains nickel 
and native iron, and possesses the general character of a meteoric stone.” 
Dune FORMATION. 
The direction of the prevailing winds is well shown in the North Island 
by the fact of sandhills being almost entirely confined to the west coast, and 
wherever the shores are sufficiently low the sand on that coast travels inland 
and forms dunes. Where the coast trends north and south, with the above 
conditions, the sand travels far into the interior. Where the coast line runs 
ait: 
1 blows along it, and does not reach far inland. 
