362 NATURAL HISTORT 



earth which I find about Auckland aud its neighbourhood is of sedi- 

 mentary origin, and I believe a chemical analysis will clearly show 

 this fact. 



The peculiar shape and conformation of the land also tends to prove 

 the same, the lay of the land generally indicates spurs or buttresses, 

 which seem to start from the volcano, and extend as rays from a 

 centre, the base of the ray is to the mountain, and it tapers off until 

 it is lost, and in most instances it takes such a shape as might have 

 been assumed by a thick fluid mass flowing down the hill. 



The vast number of volcanic rents in this neighbourhood, which 

 have all in their time poured cut liquid mud and fluid lava, serve to 

 produce great confusion and complexity in the arrangement of these 

 formations, but by care and perseverance we can generally trace the 

 course of each current of mud. In some of them we find the round 

 masses of vesicular scoria which have been incorporated in the mud 

 and hurried down into the plain below. 



In carefully analysing these avalanches of mud it is seen that each 

 has its precise location according to the period of volcanic action. 

 I believe that their difference depends in a great degree upon the 

 depth from which the matter has come. If near the surface it pos- 

 sesses certain characters, but it changes as the combustion penetrates 

 deeper into the central mass of the earth, and lastly fluid lava is 

 forced out upon the surface. We are ignorant of many of the laws 

 which regulate volcanic action, and I am certain that a noble field is 

 open in this neighbourhood for that study, for we have rudimentary 

 volcanoes in all stages of development until Ave arrive at Pongauro, 

 which presents evidences of great age and continual activity. 



The question which is naturally asked is, at what period were the 

 volcanoes about Auckland in active operation. No reliable record has 

 been preserved of that period by the inhabitants ; the natives have a 

 kind of tradition that Rangatoto, the highest of the volcanic vents 

 about Auckland, was in operation during the last century ; the name 

 itself would seem to confirm this statement, as when translated it sig- 

 nifies "Blood-red sky," a common effect of the eruption of a volcano 

 when seen by night. The discovery of lignite, evidently the remains 

 of ferns and trees now growing in New Zealand, in all directions and 

 under layers of great thickness, would lead to the conclusion that the 

 process of formation had been recent ; among the layers of earth I 

 have sent, you will find lignite taken at a great depth, viz., from a well 

 50 feet deep. I was enabled easily to distinguish among the earth, fern 

 roots and partially decomposed wood, besides which pieces of Kauri 



