THE GEYSERS AT EOTORUA. 205 



action getting weaker and 'weaker, and the cooled water in the pool 

 getting stronger all the time. The water eventually got the best of it, 

 and flowed down the geyser tubs to repeat the same action as before. 

 Having made the geyser play and cease playing several times, I re-closed 

 the drain thoroughly and went away. I did not see it play again that 

 day, and the following day about noon, when I went near, I found by 

 the marks I had left that it had not been in eruption since I left it the 

 night before. The water of the pool would boil up violently at times, 

 but there was no eruption. I then again tried what the opening of the 

 drain would do. The result was the same as on the previous day — a 

 splendid eruption of the geyser. I again watched the action for three 

 successive times, and eventually went away leaving the drain open, and 

 from the volume of steam which went up periodically from that spot I 

 could see that intermittent geyser action was taking place. 



I repeated and watched these experiments on many occasions 

 during the months of August and September, 1886. Once, the river 

 being rather high, I turned the cold water from it on the geyser when 

 in full eruption. This almost instantly stopped its action, but at the 

 same time it caused a great noise, probably owing to the sudden 

 condensation of steam within the geyser tube. After a while, however, 

 the noise ceased, the pool filled up, and all was quiet ; and as long as I 

 allowed the cold water to flow across over the mouth of the geyser tube 

 there was no eruption or even any perceptible action of the springs. 



Having thus acquired some little practical knowledge of the 

 working of this particular geyser, I began to compare it with that 

 of others to see if any of them could be made to play at will. I then 

 watched and studied the action of Pohutu, which is situated on the 

 principal geyser fissure of Whakarewarewa. This fissure supplies no 

 less than seven active geysers and blowholes, besides quite a number of 

 old geyser tubes, which have been inactive for many years, though they 

 still emit steam and make a rumbling noise, as of boiling water some 

 considerable depth below the surface. They do not seem to affect or to 

 be affected by the working or non-working of the active geysers. 



Having noticed the great irregularity of action of the different 

 geysers, I thought that it must to a great extent be attributed to 

 outside or surface influence. I noticed that when Pohutu was in 

 eruption Waikoroihi would stop, and vice versa. This showed that they 

 were kydrostatically connected, and as long as Waikoroihi played, the 

 water ejected, finding its way into the blue pool of Pohutu at a 

 considerably reduced temperature (about 160° Fahr.), would so affect 

 the cool water in the blue pool that it would not boil up whilst this 

 lasted. As it did not cause the water to rise in that pool, I concluded 

 that it might find its way back into Waikoroihi, and thus be thrown up 

 again and again. I tested this by discolouring the water in the blue 

 pool with loam, and found that, though the discolouration disappeared, 

 the small bits of grass, moss, etc., were re-ejected by Waikoroihi. 



Taking the opportunity of a visit of the Hon. Mr. Mitchelson, tin- 

 late Minister of Public Works, to our district, I explained my views on 

 these matters to him, with an imaginary sketch of the geyser tubes ; 

 Mr. Mitchelson took considerable interest in it, and allowed me to 

 expend a few pounds experimenting thereupon. At the beginning of 



