have been issued up to date : geological maps of goldfields 6i, 
copper and lead mining districts io, tinfields 5, coalfield maps 5, 
general geological maps 28, mining maps and plans 92, mineral 
distribution maps 4, of topographical maps 4. an< l horizontal and 
vertical sections 10. 
An inspection of the various geological maps shows that 
the titles attached to each explain the degree of accuracy or pre- 
cision of the field work, and that the geological groups are shown in 
colours. The colours used, it may be explained, are not based upon 
any mere arbitrary scheme. The question of the colouration to be 
adopted in geological maps is one of which very few geologists 
have had any wide experience. In the Western Australian maps 
the colours employed for the expression of the geological forma- 
tions are as nearly as possible those adopted by the International 
Geological Congress, which meets every three years. The guiding 
principle in this scheme is, briefly, that the older the formation 
the deeper is the tint. It will be noticed that the colours on the 
Survey Maps are employed in two distinct ways : 1st, solid, i.c . , 
completely covering the surface and in pale tints, and 2nd, in 
patterns. The first use is designed to have a chronological function , 
whilst the second indicates the several subdivisions, or varieties 
of rock masses, etc. To guard against the risk of the so-called 
“ fast colours ” fading, each is also distinguished by a special 
symbol. This identity of colours and patterns is essential when 
the maps are to form part of a series, and the various formations 
are to be compared one with another. It is, of course, difficult 
to devise a scheme of colouration that will meet universal re- 
quirements. The adjustment of the details of the International 
scheme of Geological Map Colouration to the requirements of the 
large scale and detailed maps of mining fields, etc,, has proved 
a well-nigh insurmountable difficulty, though on the whole it is 
sufficiently close to be intelligible to those familiar with the 
system in question. 
The writing of reports, and the other duties incidental thereto, 
naturally take time, ana lew people, unless those who have had to 
do it, adequately realise the labou. : , vn'ved in the preparation 
of such if they are to have scientific and official accuracy. Hastily 
written reports are of little real service, of no permanent value, 
and in many cases tend to materially defeat their own ends. 
For reasons which can be readily understood, geological 
inquiry in Western Australia has up to the present consisted 
chiefly of a series of unconnected observations to the co-ordination 
of which we must look to the future. 
Little or no progress has as yet been made in the direction 
of the correlation of the various geological horizons with those 
of Australasia and other neighbouring countries, though our 
observations, having been carried out in all portions of the State, 
do permit of certain broad generalisations. A great deal of the 
