446 Transactions. — Geology. 



surface, though similar in kind, are not continuous in intensity. 

 The pressure of the atmosphere, the force and direction of the 

 winds, the moisture in the air, the heat of the earth's surface, 

 the movements of the water of the ocean, are ever changing, 

 though always acting and operating in degree: hence it may 

 be said that the forces of nature, although similar in kind, have 

 been unlike in their results, as the outcome of the varying 

 differentiations that are ever in progress. 



But to return : Along the East Coast district of the North 

 Island the stratified rocks are represented by Tertiary and the 

 Younger Secondary. With a single exception there are no traces 

 of volcanic rocks : this exception is at Red Island, some miles 

 to the south of Cape Kidnappers. Fifty miles inland from the 

 coast there is the country that is generally known as the volcanic 

 district. Ruapehu in the south and White Island in the Bay of 

 Plenty are usually understood as representing its southern and 

 northern limits ; but these are by no means sufficient to deter- 

 mine the extent of the area that is the direct outcome of vol- 

 canic phenomena. The present centres of volcanic activity are 

 embraced in a large measure within the limits of the places 

 named, but it must be set down that the larger portion of the 

 North Island is the direct product of volcanic agency. From 

 the south-west corner of the Island where the extinct vol- 

 canic cone of Mount Egmont stands, right away to Tarawera, 

 fifty miles north-west of Napier, a volcanic line may be traced. 

 Right away to the north from Egmont there are volcanic rocks, 

 and it would seem as if the great bight between Egmont and 

 Kaipara Harbour represented an area of subsidence that cor- 

 responds to an area of elevation midway between Taupo and 

 the great bight above mentioned. At present the centre of 

 volcanic activity is represented by a line running from the 

 crater-pnia on Ruapehu in a north-easterly direction, and 

 embracing the whole of the area affected by the Tarawera 

 eruption of 1886. But this line of activity far from represents 

 the area of volcanic energy such as the Taupo Plateau has 

 experienced in past times. The attention that has been paid 

 to the active phenomena as they appear to-day has led to the 

 partial neglect of historical volcanic phenomena in relation to 

 the Island as a whole. As viewed by the activities such as they 

 appear to-day, the volcanic phenomena compared with the past 

 are small and almost insignificant. When it is considered 

 how extensive is the volcanic belt and how widely distributed 

 are the lavas of rhyolite, one is led to inquire as to the magni- 

 ficent grandeur of the volcanoes of the past, or. if not volcanoes, 

 i lien of welling seas of lava that spread in sheets over the Taupo 

 Plateau for many hundreds of square miles. At the present 



