5. “On the Occurrence of Black Sulphur in the Native State,” by Sir James Hector.
The specimens were sent by Captain Mair, Rotorua, with the following note: - “I send you a matchbox full of funny little globules which I obtained from an active hot spring in the Waiotapu Valley, at the back of Maungakakaramea. They appear to be manufactured on the spot, and are thrown out by millions. I have never seen anything like them elsewhere.” These globules proved on analysis to consist of sulphur 88.81 per cent.; water, 9.46 per cent.; carbon, '24; loss 1–39. They were hollow spheres of irregular form, and appear to have been filled with steam when thrown up in the air, as they seem to have burst in falling by the formation of a vacuum in most cases. They were about the size of peas, and were interesting as being the first instance in which allotropic sulphur had been found in the natural state. Captain Mair also adds the following note with reference to the Tarawera disturbance:-“While in the Waiotapu Valley, on the 2nd July, 1887, we heard some extraordinary noises, apparently deep in the ground under our feet, and travelling along the earthquake rents from the north-east to the south-west. They occurred four times one day, and were like an express train dashing across an underground bridge. There was no perceptible tremor of the earth. The old-Maoris to whom I mentioned the circumstance said the sounds were caused by the pent-up steam bursting into and filling large caverns in the earth. I do not know whether this is a scientific explanation, but it certainly seems a plausible one.” Sir James Hector explained that it was about this time that great changes took place in the appearance of the district by the sudden rising of the waters of Rotomahana to their original level, while the new cold-water lake that had formed in the fissure since the eruption had disappeared; and it was probably the rushing of the underground waters, in establishing this readjustment of levels, that gave rise to the noises reported.