S28 Essays. 



Comparisons witA: the South Islakd. 



It is a point worthy of note tliat tlie A^ertical oscillations of tlie two great 

 islands of New Zealand seem to have differed very mucli, botL. in time of 

 occurrence and in degree. In tlie Nortli Island the depression in tertiary 

 times would appear to have Leen 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 Avas probably the case. 



In the North Island the tertiaries occupy a far greater area than in the 

 South Island, which alone Avould 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 tAvo peaks 

 only in the former island uoav carry perpetual snow, viz. Euapehu 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 Avhich has been found on the surface of the 

 country is that Avhich Avill be now described. It Avas found in the year 1863, 

 in front of Mr. Donald's house, at Manaia, near the left bank of the Wai- 

 ngawa Eiver, in the Wairarapa, ProA'ince of Wellington. The plain is here 

 composed of coarse gravel. The aerolite Avas found on or near the surface, 

 and measures 9 in. by 6 in. by 7 in. 



A portion of this interesting specimen Avas forAvarded for examination to 

 the Laboratory of the Otago Greological Survey, at Dunedin, and the follow- 

 ing notes respecting its composition have been furnished by Dr. Hector: — 



" The fragment submitted for analysis Avas externally of a rust colour with 

 an exudation of chloride of iron. The freshly fractured surface Avas of a 

 dull grey colour. Its hardness Avas betAveen 5 and 6, and its specific gravity 

 3'254. 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." 



DuisT] Formations'. 

 The direction of the prevailing winds is Avell shoAvn in the North Island 

 by the fact of sandhills being almost entirely confined to the Avest coast, and 

 Avherever the shores are sufficiently Ioav 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 

 east and west the sand bloAvs along it, and does not reach far inland. 



