580 Transactions. — Miscellaneous. 



theory to account for the inequahty in the thermal action of 

 these springs and geysers. The generally-received opinion 

 was that the geysers were influenced by the wind : with 

 southerly wind they were quiescent, and with uortlierly they 

 were active. As I could not well understand how the wind 

 could affect geysers or springs situated in sheltered positions, 

 I began a system of personal observation, and soon found 

 that southerly wind generally meant high barometer, and 

 northerly a low one ; and, if I could not understand the wind 

 theory, I could the hydrostatic effect, and the influence of 

 atmospheric pressure, which was simply equivalent to a 

 reduction in the column of water. Every spring and geyser 

 being naturally hydi'ostatically balanced, the reduction by any 

 means of the weight of the column of water should bring a 

 correspondmg increase in the activity of the spring. Acting 

 upon this theory, I determined to experiment privately upon 

 Te Puia, a thermal spring in a secluded spot near an old pa, 

 on the right-hand side and well down in the bed of the Pua- 

 renga Eiver, therefore little influenced by winds. It was at 

 that time boihng, but not very actively. By means of a drain 

 which I cut in the sand formation by the level of the river 

 I removed about 2ft. of the water from the pool which formed 

 around the spring. This removal of 2ft. of dead-water had an 

 immediate effect on the spring ; it began to boil furiously, and 

 a few minutes afterwards burst into a geyser, throwing water 

 from 30ft. to 40ft. high, discharging at the same time the 

 whole of the dead-water of the pool. I watched this eruption 

 of what I thought a new geyser — for there was vegetable 

 growth of several years' standing around it — with wonder, and 

 with a certain amount of anxiety, as I began to fear that I 

 had started something which I could not control. However, 

 after a few miimtes, taking advantage of a decrease in the 

 eruptive force, I ran to the drain I had made, and refilled it as 

 quickly as possible, causing part of the water thrown up by 

 the geyser to be again caught in the pool or basin. Here it 

 soon accumulated, and after a while the geyser-action ceased, 

 and the water of the pool ran down the geyser's tube, together 

 with a considerable quantity of water from the river which 

 had flowed back through the partially-closed drain. In about 

 ten minutes the tube was filled with cold water to the surface. 

 I watched it for a while, and saw the water getting hotter 

 and hotter. Eventually it began to boil, but without any 

 geyser-action. After a time I again opened the drain, and 

 almost immediately there was another splendid eruption 

 similar to the former. I determined to allow this to play, and 

 see what it would do, as I began to have some confidence in 

 my ability to control it by the same process as before if it was 

 found necessary. It played for about twenty minutes, the 



