Malfkoy. — Or, Geyser-action at Rotorua. 579 



the conclusion already arrived at by means of the tbnes. The 

 observations are not such as to enable us to ascertain the 

 depth of the origin ; they are opposed to one at great depth — 

 indeed, the origin was probably very shallow. 



Dr. Lemon has kindly allowed me to supply earthquake 

 memorandum forms to a large number of telegraph-stations 

 near Cook Strait, so that I trust this attempt is only the 

 first instalment towards the exact determination of the epi- 

 centric areas in that district. 



Postscript. — The earthquake of the 4th December, 1891, 

 for which the number of data is very large, gives nearly the 

 same origin. It will form the subject of a separate paper. 



Abt. LVII. — On Geyser-action at Rotorua. 



By Camille Malfkoy, C.E., J. P., Chevalier de la Legion 



d'Honneur. 



[Bead before the Auckland Institute, 22nd June, 1891.'] 



Plates XL.-XLII. 



Being appointed engineer in charge of the Government 

 thermal -springs district at Eotorua immediately after the 

 eruption of Tarawera, in 1886, it became part of my duty to 

 observe and report on any changes which might take place in 

 the hot springs, geysers, &c. The eruption seemed to have 

 had great influence over them. Many which had been 

 quiescent, and some which had been considered as dead 

 (having in the course of time become filled with rubbish and 

 overgrown with weeds and brushwood), suddenly burst into 

 renewed activity; and almost daily during the first six 

 weeks after the eruption I could observe some changes in the 

 thermal action — something new here and there throughout 

 the district. 



The geysers immediately attracted my attention. Waikite 

 Geyser, at Whakarewarewa, which had been quiescent for 

 about ten years, again burst into full activity, with eruptions 

 about every quarter of an hour. Pohutu, Wairoa, and the 

 other geysers were also playing occasionally, but were very 

 irregular in their action. Sometimes weeks would elapse 

 without one or the other of them showing any sign of activity, 

 whilst at other times they would be active for several days in 

 succession. 



Not having had a long acquaintance with the district, I 

 made inquiries of old residents (European and Maori) for any 



