290 KECOED OF SCIENCE FOR 1886. 



output of lava from all tbe several openings amounted to from 40 to 60" 

 cubic meters per second, and tbe rapidity of flow of the stream was from 

 40 to 60 meters per minute near the source. The stream extended 

 in all 6.5 kilometers, stopping within 327 meters cf Nicolosi, and the 

 whole voluiue of lava emitted was estimated at 66,000,000 cubic meters. 

 (Compt. Rend., cii, 1589.) 



On the morning of June 10, 1880, a remarkable volcanic eruption be- 

 gan in the lake district of the North Island of New Zealand. By di- 

 rection of the Government, acting with the utmost promptness, Dr. 

 James Hector, director of the Geological Survey of New Zealand, at 

 once began a scientific examination of the phenomena, starting with 

 assistants for the scene of the outbreak on the afternoon of the same 

 day on which the eruption commenced. His preliminary report, on 

 wliich the writer has mainly relied for the following brief account, is 

 given in Nature, xxiv, ^^89. The focus of the disturbance was ascer- 

 tained to be in a line 7 to 10 miles long, extending in a northeast-south- 

 west direction from the north end of the Tarawera Range to Okaro 

 Lake. The outbreak began at 2.10 a. m. by an eruption from the top 

 of Wahanga, the north peak, followed in a few minutes by a more vio- 

 lent one from Ruawahia, tbe middle peak, and a little later by a third 

 one from the south end of the range. By the last explosion the mount- 

 ain was split in two, and Percy Smith found the fissure to be 5 chains 

 wide and the eastern part to have been blown away and scattered in 

 debris over the country. (Nature xxxiv, 554.) The earthquake shocks 

 at this time were not very severe. But about 4 a. m. a violent outburst 

 of a different nature occurred, attended by loud reports and widely 

 felt earth shocks. This was the outburst of an immense volume of 

 steam, carrying pumice dust and rocks, which proceeded from the site 

 of Rotomahaua Lake, southwest of Tarawera, and formed a thick cloud 

 in the higher atmosphere, where the vapor condensed to such an extent 

 that the suspended solid matter fell in the form of mud, overwhelming 

 the settlement of Wairoa to a depth of 12 inches. The site of this 

 eruption is a great fissure which seems to commence as a narrow rift at 

 the northern end from the great rent which has been formed in the 

 south end of Tarawera Mountain. This rent appears as if a portion 

 of the mountain, measuring 2,000 by 500 feet and 300 feet deep, had 

 been blown out, leaving a ragged chasm, from which steam was issuing 

 when observed. The great fissure cuts across Lake Rotomahaua, where 

 were formerly the famous Pink Terrace and White Terrace, but wliere 

 there are now seven powerful geysers, at intervals throwing up water 

 and mud to a height of 600 to 800 feet, the largest geyser rising from 

 the position formerly occupied by the Pink Terrace. The rain of mud 

 which overwhelmed the country is attributed to the condensation of 

 the heavy vapor and dnst cloud under the influence of a cold vsouth- 

 west wind. When visited steam was still rising from the site of Lake 

 Rotomahaua, forming a cloudy pillar 12,000 feet high. Dr. Hector 



