462 Tratisactions. — Miscellaneous. 



received from Captain Barker the results of the soundings taken, 

 and was able to lay before them a sketch-map showing the form 

 of the Pacific, tinted according to the soundings he had obtained. 

 The first result was that the sea area between New Zealand and 

 the Chatham Islands had a depth of about 1,300 fathoms. The 

 water gradually shoaled, until when close to the Chatham Islands 

 the depth is found to be 160 fathoms, or about the same as in 

 Cook Straits. Immediately beyond the Chathams there was a 

 sudden plunge, just the same as to the west of New Zealand. 

 Deep soundings of 3,000 fathoms were carried to long. 118° W., 

 when the water suddenly shoaled and a great bank was found, 

 on which the depth was determined by a number of soundings 

 shown in the return sent by Captain Barker. Another plunge 

 reached 3,000 fathoms; then the depth shoals to about 1,500 

 fathoms, at 500 or 600 miles from South America. Near the 

 coast 1,200 fathoms was found, which appears to be the ruling 

 depth of the South Pacific, subject to these great depressions. 

 From New Zealand to the Chatham Islands the bottom is found 

 to be level. From the Chatham Islands, Captain Barker first 

 met with a grey mud, passing into brown mud with minute 

 white shell-sand. Yellowish sand was found in the South 

 Pacific "pot-hole," after which a brown mud, followed again 

 by grey mud with shells. This information confirmed the views 

 of Professor Hutton, in opposition to the views of Wallace, that 

 in the South Pacific there is a submarine plateau, indicating 

 the former existence of a great continental land connection 

 between South America and Australia. 



Dr. Hector next referred to a report which he had made to 

 the Hon. the Minister of ]\Iines, dated the 23rd inst., for full 

 particulars of the observations he had been able to make regard- 

 ing the recent eruption of Mount Tarawera. He pointed out 

 that the eruption of Ngauruhoe in 1870 was really much more 

 important than the late outburst, though less advertised by sad 

 incidents, for then great lava and steam eruptions continued for 

 a considerable period. Keferring to a large geological map, he 

 gave a general sketch of the geology of the district. Omitting 

 the Post-pliocene and newer coastal formations, the whole coun- 

 try, from the sea-level in the neighbourhood of Wanganui, was 

 originally covered by a crust of limestone of Older Pliocene 

 age, that rose up to 4,000 feet on the slopes of the Kaimanawa 

 Range. Under this there was the middle tertiary, or blue papa 

 (or marlstone) ; but the whole series did not exceed 2,000 or 

 3,000 feet in thickness, and rested on much older rocks wherever 

 its base had been observed. The crust of limestone presents the 

 same character throughout, from the sea-level to the greatest 

 altitudes. It did not now constitute a continuous sheet, but 

 occurs only in isolated masses that liave remained perched ou 

 the hill tops. As it is largely composed of shells of huge 



