THE FINDING OF WORKABLE COAL. 209 



Draiy areas. The fact Las, therefore, been established by actual survey 

 and observation that the Waitemata beds are conformable and belong to 

 the New Zealand coal series — an opinion which has always been 

 maintained by Sir James Hector. 



It may be as well before pursuing this subject further to shortly 

 inquire into the physical conditions considered necessaiy for the for- 

 mation of coal. By the geologists of the early part of this century 

 it was believed that workable true coal could only be found among a 

 certain class of shales and sandstones of the palaeozoic or primary period, 

 to which the age and name of carboniferous had been affixed ; and it 

 may be as well to note here that this conclusion was fully sustained by 

 their experience of the coal measures of Great Britain, Continental 

 Europe, and North America, all of which were found to belong to this 

 period. But the many brilliant discoveries of the past forty years have 

 led to a remarkable evolution of thought and theory in every branch of 

 knowledge, and in none is this seen more conspicuously than in the 

 science of geology. True coals of superior quality have been found in 

 the Jurassic and triassic rocks of India and New South Wales, and in 

 New Zealand in rocks that belong to the base of the tertiary period, 

 but which possess in some places a secondary facias, and hence have 

 been called cretaceo-tertiary in age. 



Thus it is seen that there is interposed between the carboniferous 

 coals of Britain and the cretaceo-tertiary coals of New Zealand the 

 whole of the secondary and a part of the primary periods, representing 

 an immensity of time of such infinite duration as to defy the compre- 

 hension of our finite minds. This wide lapse of time renders it easy to 

 explain the great geological differences which exist between our own 

 and the Old World coals. Perhaps the most marked distinction lies in 

 the character of the vegetation of which each is composed ; for, while 

 the European coals are mainly composed of the remains of a flora 

 belonging to the cryptogamic kingdom, truly characteristic of the 

 palaeozoic period, the New Zealand coals are composed of the remains 

 of a varied forest vegetation which everywhere marks the advent of the 

 tertiary period and the luxuriant flora of the present time. In the 

 forests of our coal period there flourished two species of the kauri, 

 which at that time grew all over New Zealand ; three species of the 

 beech, so commonly and erroneously known throughout the colony by 

 the settler's name of birch ; also the oak, laurel, myrtle, heaths, palms, 

 ferns, grasses, etc. 



It is now recognised by geologists that coal could form at any 

 period of the earth's history if the necessary conditions existed, and it is 

 probable that these conditions have continued the same through all 

 geological time. They were : (1) a humid, temperate climate, favouring 

 the growth of a dense vegetation ; (2) flat or gently sloping, low-lying 

 areas, favourable for the accumulation of thick deposits of vegetable 

 humus and peaty matter ; and (3) a stationary, or nearly stationary 

 state of the land to permit a long-continued and uninterrupted growth 

 of vegetation. 



In New Zealand our coal areas are mostly littoral, of small extent, 

 and patchy, characteristics resulting principally from the insular and 

 mountainous nature of the country in older tertiary times. Where the 



