208 JOUENAL OF SCIENCE. 



pent-up steam rushes up the (geyser) tube with a force proportionate to 

 the depths at which the reservoir containing this force may be situated, 

 and acting on the principle of a Giffiu-d ejector, the pent-up steam 

 rushes up the tube, taking up with it a certain quantity of the water 

 which may find its way into the tube, and ejecting it into the air in the 

 form of high, low, or intermittent geysers, in proportion to the different 

 size, position, force and volume of the spring, and other circumstances 

 of the case. 



I have also observed that the chemical composition of the water is 

 sensibly altered by the different actions of the geysers. Thus, if the 

 geyser is made to play very actively the water becomes softer to the 

 touch, it being more silicious and oily than when the geyser action is 

 subdued and allowed to boil up quietly. 



This will account for the comparative rapidity observed in the 

 formation of terraces and mounds around the most active geysers, and 

 the very small amount of silica deposited by springs of less pressure and 

 activity. 



THE PROSPECTS OF FINDING WORKABLE 



COAL ON THE BANKS OF THE WAITEMATA. 



BY JAMES PARK, F.G.S. 

 (Read at the Meeting of the Auckland Institute on 22nd June, 1891.) 



The recently reported discovery of a thin, irregular seam of coal in 

 the cliffs near North cote has again directed attention to the probable 

 existence of workable coal in the vicinity of the city of Auckland. The 

 great economic importance of this question has long engaged the 

 attention of the Director of the New Zealand Geological Surveys, and 

 during the past ten years a number of surveys have been undertaken by 

 the officers of his department with the view of collecting sufficient data 

 to definitely determine the relation existing between the "VVaitemata 

 beds and the New Zealand coal-bearing series. 



In the years 1879, 1880, and 1881 Mr. Cox, late New Zealand 

 Assistant Geologist, examined the country extending northwards from 

 the Auckland isthmus to Whangarei on the east coast and the Upper 

 Kaipara on the west. He arrived at the conclusion that the Wai- 

 tematas, as typically developed at Orakei Bay and Port Britomart, 

 were unconformable to and had no connection with the brown coal 

 measures of Drury and the Lower Waikato Basin. In 1885 and 1886 

 I re-examined the same country, and also made a close and detailed 

 survey of the shores of the Hauraki Gulf from Auckland to the 

 Maraetai Bange. The result of my observations tended to show that 

 no uncorformity existed from the top of the Waitematas to the base of 

 the Papakura series; and subsequent surveys by Mr. McKay, F.G.S., 

 the present assistant geologist, have shown that the Papakura beds rest 

 quite conformably on the brown coal measures of the "Waikato and 



