Malfroy. — On Geyser-action at Rotorua. 585 



which either of the springs can be made to play as a geyser at 

 will. (See PI. XLI.) 



To keep the springs quiet, low, and cool during the time 

 the w^orks were being carried out, cold water from the town 

 main was injected into one of the three spring-tubes, pumping 

 it with an ejector out of another, whilst the work of cementing 

 the geyser-tube was going on in the third; and by shifting the 

 injector- and ejector-pipes from one spring-tube to another I 

 had the three geyser-tubes firmly secured. These works were 

 finished early in May, 1890, and the springs were thus kept 

 quiescent for three weeks to allow the concrete to set properly, 

 and eventually four days longer, so as to start them into action 

 for the first time on the Queen's Birthday at 2 p.m. A con- 

 siderable number of people gathered to see this novel experi- 

 ment. The new fountains were christened the Malfroy's 

 group of geysers, their distinctive names being the "Victoria," 

 the " Nelly," and the " May." 



The three geyser-tubes, A, B, and C, on Plate XLI., consist 

 of Gin. earthenware pipes sunk in the ground from 6ft. to 9ft. 

 deep, right over the outlet of the springs, secured with cement 

 concrete, and allowed to project about 2ft. above the water- 

 level of the basin, a, b, and c, the three valve-pipes connected 

 with A, B, and C, consist of 4in. earthenware pipes from 6ft. 

 to 10ft. long, laid zig-zag, and thus forming double traps ; they 

 are provided with wooden valves to regulate the quantity of 

 return water to be admitted iiito any of the geyser-tubes. 



D is a supposed steam-chamber, showing probable con- 

 nection between the geyser-tubes and the hot fissure or fis- 

 sures which supply the heat or superheated steam and water 

 to the springs. 



When the three geyser-tubes are allowed to work without 

 interference on the surface, C begins to get heated, the water 

 rises in its tube and discharges through the small pipe c, the 

 action and heat increasing steadily for a quarter of an hour or 

 so ; eventually the water boils furiously, and, as the wa,ter and 

 steam come up the tube with considerable velocity, it takes 

 the path of least resistance, and is shot up the tube and ejected 

 into the air to a height of from 15ft. to 30ft. 



This geyser-action lasts from five to ten minutes, dying 

 away gradually until the cooled water gathered in the basin 

 penetrates into the tube C from the valve-pipe c, which even- 

 tually stops the geysei -action, the water sinking rapidly down 

 the tube. It is then quiescent for about ten minutes, while 

 the heat from below seems to accumulate its force. The column 

 of water in the geyser-tube again rises, begins to discharge, 

 heats up, and repeats the geyser-action as before explained. 



This intermittent action of C goes on for an hour or two, 

 during which time the temperature of the water in tube B is 



