170 PROCEEDINGS OF SECTION A. 
This necessity is amply illustrated by the magnetic survey of 
the British Isles. The first of these surveys was executed i in the 
years 1834~38, the second in 1857-62, and the last in the years 
1884-88, and Sih es to the epoch 1886. 
It may be appropriate to mention that two of these surveys 
were recommended by the British Association for the Advance- 
ment of Science. 
Turning now to the Australasian colonies, we find a most 
excellent magnetic survey of the colony of Victoria made by Dr. 
Neumayer in the years 1858-1864. No other part of Australasia, 
however, has been magnetically surveyed. 
A new survey of the colony of Victoria is of the greatest 
importance, as it would settle the question of the secular varia- 
tion ; and with the greater facilities of the present, some defi- 
ciencies which were inevitable in the first survey, owing to the 
conditions of the colony forty years ago, could be remedied. A 
magnetic survey of the whole of Australia, of Tasmania, and New 
Zealand may at first sight appear to be a task of enormous mag- 
nitude, yet it would be well worthy of these colonies to undertake 
it ; and I consider that the present or immediate future offers 
good opportunities for its initiation, for the following reasons, 
namely :— 
We have at present a large body of geodetic and land surveyors 
whose services must gradually Teeente less and less required 
within the special sphere of their calling, owing to the progressive 
settlement of the country. Among these professional men it 
would not be difficult to pick, say, half-a-dozen in each Colony 
possessing the required aptitude for this delicate class of work. 
‘The necessary training would be a matter of a few months, the 
instruments a matter of a few hundreds of pounds for each 
Government, and the field-work a matter of a few years. 
Permanent magnetic observatories, in addition to Melbourne, 
could be established with all desired security for efficiency at the 
Sydney, Adelaide, and Perth Observatories, with little extra 
yearly expense beyond the initial cost of the instruments. 
Other permanent magnetic observatories would be required at 
Brisbane, Port Darwin, Hobart, and at a southern place in New 
Zealand. The last two would possess an additional importance 
over the others, owing to the circumstance that Hobart is the site 
where a valuable series of magnetic records was secured during 
the years 1841-48 for the Royal Society of London, which would 
be of immense advantage to deduce the values of secular varia- 
tion, and New Zealand on account of its being the most southern 
station of easy access in our hemisphere. 
Port Darwin might not necessarily remain in activity after the 
completion of the survey. Brisbane would always be of great 
service—Ist, as a base station for its vast territories, where the 
