ANNIVERSARY ADDRESS. So 
millionaire would take it into his head to have borings made in 
some of the Pacific and Indian atolls, and bring home cores for 
slicing from a depth of five hundred to six hundred feet.” 
IIT.—-SumMaryY OF OUR PRESENT KNOWLEDGE OF THE STRUCTURE 
AND ORIGIN OF THE BLuE Mountains oF New Soutn WaAtgs. 
In the following remarks only the most salient features are 
touched upon. 
References by previous obser vers.—The most important of these 
is probably that of Charles Darwin.’ My excuse for introducing 
a lengthy quotation from Darwin’s work is that the passage is 
extremely suggestive on many points of importance in the structure 
of the Blue Mountains, which I propose to criticise. After 
describing the great platform of sandstone which rising westwe.rds 
attains an elevation in places of over 4,000 feet, at a distance 
from Sydney and the coast of about one hundred miles, he states 
that the sandstone is at least 1,200 feet thick, ‘and in some parts 
is apparently of greater thickness; it consists of small grains of 
quartz, cemented by white earthy matter, and it abounds with 
ferruginous veins.” * * * The sandstone contains pebbles 
of quartz; and these generally increase in number and size 
(seldom, however, exceeding an inch or two in diameter) in the 
upper.beds : I observed a similar circumstance in the grand sand- 
stone formation at the Cape of Good Hope. On the South 
American coast, where Tertiary and Supra-tertiary beds have 
been extensively elevated, I repeatedly noticed that, as the sew 
= a shallower, the force of the waves or currents increased.’? 
“I was surprised at observing that in some specimeus - 
(of sandstone.—T.W.E.D.) nearly all the grains of quartz were so 
perfectly crystallised with brilliant facets that they evidently had 
not in their present form been aggregated in any previously exist- 
ing rock.” * * * “The strata of the Blue Mountains appear’ 
1 Gedlogical Observations on the Volcanic Islands and parts of South 
America visited Pp Rs voyage of H.M.S. * Beagle.’ Second edition, 
‘pp. 146-154. 2 Op. cit., 147. 
C—May 20, 1896. 
