Pond and Smith. — On the Eruption of Mt. Tarawera. 365 



and its exit from Kotokakahi so raised as to prevent the outflow 

 of water. The water of all the lakes was grey and turbid, from 

 the semi-liquid mud which had been precipitated into them. 

 On the shore of the Tikitapu Lake was a thin liquid rim of what 

 appeared to be gravel, but which on closer inspection proved 

 to be small fi'agments of scoria and a few quartz crystals, washed 

 from the mud deposit by the waves caused by the storm. 

 Already the mud liad begun to descend the steeper mountain 

 sides in avalanches, with loud rattling noises. 



The Material composing the Ejected Matter. 



Having viewed the deposition of the material, we will now 

 consider its structure and composition. 



We have, first, the dry ash laid in the vicinity of Eotomahana 

 (south side), and extending in a gradually reducing thickness to 

 Galatea. Then the mud precipitated over the Wairoa, Kotoiti, 

 Okareka, and Okataina. The dry ash carried in the shape of 

 fine powder over Tauranga, and as coarse sand at Whakatane 

 and Opotiki. Then we have a secondary coating of mud over- 

 lying the dry ash in the immediate vicinity of the geysers at 

 Eotomahana, and the varying degrees of fineness of the ash 

 deposited at long distances — notably at Whakatane, where a 

 coarse sand fell for the first few hours, followed by a very fine 

 dust for some hours afterwards. The same circumstance, but 

 in a less conspicuous degree, was noted at Tauranga. In the 

 order as arranged, we find the mud to be chiefly composed of 

 quartz, in the form of fragmentary rock crystal ; and as sinter, 

 both white and coloured pink by peroxide of iron ; together with 

 a large amount of volcanic scoria in fine fragments, and 

 exceedingly vesicular. This fragmentary scoina we shall find to 

 be in very different proportion as we proceed, and the greatest 

 interest will be felt in this fact, together with its bearing on the 

 future fertility of the soil on which it has fallen, or will itself 

 have replaced. We have not, however, found pumice to any 

 large extent. In some of the older fragmentary rocks isolated 

 patches were attached, but the fine deposits are singularly free 

 from it.''' 



In addition to these varieties of ash, we have also the 

 solid portions of stone which have fallen, not merely in the 

 vicinity, but also at long distances from the scenes of eruption. 

 The materials thrown out vary considerably. In the immediate 

 neighbourhood of the craters are to be found stones from a few 

 ounces to over a ton hi weight, f These vary considerably in 



* Some few specimens of newly- formed pumice were afterwards found 

 scattered over the ash-fields, but the quantity is so small as to escape any 

 but the most careful search. 



t Some have since been found which would weigh nearly 10 tons. 



