240 JOURNAL OF SCIENCE, 
views with numerous lime-light transparencies of the principal 
geysers. 
Auckland, August 11th, 1884. H.G. Seth Smith, Esq., Presi- 
dent, in the chair. 
New member—T. Steel. 
Papers—i. ‘‘ Description of Tuhua, or Mayor Island,” by E. 
C. Goldsmith. This was a careful account of the chief physical 
teatures of Mayor Island, situated in the Bay of Plenty, between 
Tauranga harbour and Tairua. The island is wholly volcanic, 
and contains numerous extinct craters, one of which is of unusually 
large size. From it streams of lava had been poured into the sea, 
some composed of basalt, some of obsidian or other acidic volca. 
nic rocks. The whole surface of the island is thus excessively 
rough and difficult to traverse. A hot spring exists on the 
northern shore, and a portion of the floor of the main crater is 
occupied by two shallow lakes. There are no running streams, 
and only two or three springs. In former times the island had 
been thickly peopled by Maoris, and nearly all the high peaks 
had been fortified as pahs. At present the inhabitants number 
only four or five. 
3. “ Buddhism and its Evolution Theories,” by Jj. Murray 
Moore, M.D. The first portion only of this paper was read, 
and was devoted to an account of the life of Buddha; the 
writer reserving for the second part his views respecting the his- 
tory and development of Buddhism. 
3. ‘« Geyser Eruptions and Terrace Formations,” Part IL., by 
J. Martin, F.G.S. The hot lake district of Auckland is perhaps 
more widely celebrated for its magnificent terraces and other beau- 
riful structures tormed by its geysers and thermal springs, than 
tor the wonderful displays of volcanic activity which formed the 
subject of the first part of this paper. While many of the hot and 
boiling springs leave little or no deposit around their outlet, or to 
mark their course, by far the larger number are distinguished by 
the structures formed in great variety by their overflowing waters. 
The characteristic features of each variety of form are determined 
by :—1. The chemical constituents of the substances held in solu- 
tion. 2. The amount of mineral matter dissolved or held in sus- 
pension in a given quantity of water. 3. The amount of heat and 
pressure to which the water has been subjected before its discharge. 
4. The reguiarity or periodicity of the eruptions. 5. The confor- 
mation of the surface covered by the overflow. 6. The nature of 
the obtruction which interfere with the flow of the discharged 
water. Silica, which is the most important mineral contained in 
these springs is insoluble at ordinary temperatures, but is readily 
dissolved by intensely heated water under great pressure. It is 
rapidly deposited upon release of pressure, and a more gradual 
deposition takes place with decrease of temperature. Silica is 
also volatilised by high pressure steam, and reforms as a fine 
sublimed deposit upon the escape of its vaporous solvent. The 
silica liberated by the gradual decomposition of the rhyolitic rocks 
traversed by these hot springs is in a condition greatly favouring 
its solution, and the solvent power of the water is also materially 
increased by the presence of alkalies in solution, Finely divided 
silica held in suspension may also add to the deposits found dur- 
eee 
