Ill 
One of the most eminent of living geologists recently said: — 
"perhaps the shortest definition that has been made of our science, and 
"one equally acceptable to its students and to those who view it from the 
"outside, is, that Geology is the science of the structure of the earth. It is 
« in and around that earth structure that our geological ideas centre ’’ 
It has been found necessary for reasons which will be set 
forth at length during the course of the lecture, to establish a 
branch of the public service, which is charged with certain 
important geological investigations. Nearly every civilised 
country in the world has established a geological survey in some 
form or another, and the question is often not unnaturally asked, 
why does an efficient geological staff now form a necessary part 
of the machinery of government of all nations ? 
The ultimate object of any such survey is undoubtedly to 
promote the development of the natural resources of the country, 
and this can only be done by more or less systematic efforts to 
decipher the geological structure, and correctly interpret its 
history. In so far as a thorough appreciation of the peculiarities 
of mineral deposits are concerned, such can only be arrived at 
after a thorough understanding of their natural history ; whilst in 
the search for new deposits and in defining the probable downward 
limits of those already known, geologists have to be guided to a 
large extent by a knowledge of how particular ore-bodies have 
been formed. 
The fundamental object, therefore, of the geological survey 
of anv country, when viewed from the scientific standpoint, is 
by a more or less systematic investigation of its structural geology, 
organic remains, and its mineral resources to ariive at a true 
understanding of its geological history. 
These objects are carried out in a partially settled countiy 
such as our own by means of : — 
(a) Reconnaissance surveys of those poitions of the State 
about the structure ' and resources of which little 
is known ; 
(b) Detailed geological surveys of mining centres under 
active development, etc. ; 
(c) Chemical and mineralogical examinations of soils, 
rocks, minerals and natural waters collected by the 
field staff, and under certain specified conditions 
by prospectors and others ; 
(d) Palaeontological investigations ; 
(e) The maintenance of a geological museum ; and 
(/) The publication of the data amassed. 
History. 
It may, perhaps, have been forgotten that the inception of 
active mining operations in Australia dates fiom the year 1842, 
when lead and copper mines were first discovered and worked at 
Waneranooka, in the Northampton district of Western Australia 
