234, PROCEEDINGS OF SECTION A. 
with all the precision necessary for the determination of the figure 
of the earth, yet for all the purposes, and they are many, of the 
management of the Crown estate, it is of the highest value. Its 
limits are indicated roughly on the map marked D, 
WESTERN AUSTRALIA. 
The trigonometrical surveying done up to the present in 
Western Australia consists almost entirely of long chains of 
triangles, embracing a very large extent of the western sea-board, 
and in some cases extending to a considerable distance inland. 
The section between Fremantle and Geraldton was observed 
some twenty years back, but the bulk of the remainder has been 
carried out during the last seven or eight years. Owing to lack 
of the slight additional means needed for undertaking an adequate 
survey, the angles have been measured only with small instru- 
ments, generally 6-inch theodolites, reading to 30 seconds, though 
at some few places 8-inch theodolites, reading to 10 seconds, were 
used, 
Work of this character, if viewed as preliminary to a survey of 
a better class, no doubt serves a useful purpose, as affording a 
frame-work on which to build the rough maps required in the 
early stages of the settlement of so vast a territory. It, however, 
cannot fulfil properly that function of a triangulation which, 
from an economic point of view, may be considered as one of the 
main ones, namely, serving as a check on the field work, so as to 
reduce to a minimum the cost of field inspection of the chain 
surveys. To serve that purpose it is imperative that the trigono- 
metrical survey should be indisputably better than the work it is 
to control. From another point of view, also, it is to be desired 
that, if undertaken at all, a trigonometrical survey should be 
carried out with greater precision. The question of the calcula- 
tion of the triangulation itself is what is referred to, for in work 
of such approximate nature it cannot but be found that on joining 
between the different bases and astronomical stations, discrepan- 
cies of length, azimuth, and position are shown of such magnitude 
that their proper distribution is beyond the reach of any systematic 
method of adjustment, so that appeal has to be made to some 
arbitrary means, always a most unsatisfactory resort. 
Six bases have been measured, viz., at Perth, Wyndham in the 
Pilbarra District, and on the Fitzroy and Ashburton Rivers. 
Their lengths were obtained by the use of steel wires, 66 feet 
long, fitted with knife edges at the ends, changes of temperature 
being observed during the measurement, and allowed for. 
Astronomical observations were taken at points about 200 
miles apart, latitudes being determined by meridian altitudes of 
stars and azimuths by observation of circumpolar stars at their 
