84 PROCEEDINGS OF SECTION A. 
tribution of the lines of equal dip and _ equal 
intensity present appearances very similar to those shown 
on the magnetic map of Victoria prepared by Dr. Neumayer 
as a result of the survey conducted by him between 1858 and 
1863. Dr. Neumayer’s map is based on determinations 
made by him at 235 stations. 
As regards their shape, the lines of equal declination came 
somewhat. as a surprise to us when plotted, but we see no 
reason to believe that the map does nct show their actual 
distribution with such accuracy as might have been expected 
from the small number of stations at our disposal. The 
declination (omitting the Southport determination) ranges 
from 10° 16! 35'' EK. at Eaglehawk Sie to 1° 5719 35me 
at Strahan. 
As regards the Southport site, the abnormalities there 
shown do not present themselves merely in one of the mag- | 
netic elements, but in all three. Determination of the dip 
was made with three needles, the results being——-72° 12! 8”, 
72° 25/ 1/', and 72° 29' 20’". The differences between 
these readings are too great to be due to errors of observa- 
tion, and that the instrument was in good order is shown 
by the fact that at a later date one of the 
writers made a determination of the dip, at the 
Melbourne Observatory with this imstrument, while 
Mr. Baracchi used his, and our mean results did not 
differ by more than 2’ of arc, though neither instrument 
wag working toa well, owing to the humidity of the atmo- 
sphere. 
The declination at Southport is 11° 44’ 1", while the 
horizontal intensity works out as -1932, both results being 
quite discordant with the results obtained at other stations. 
This again is not due to any error in the instrument, as in 
determining the horizontal intensity with it..at Melbourne, 
the results obtained did not differ from thoseof Mr. Baracchi 
until the fourth place of decimals was reached. The 
cause of the discrepancy is probably to be found in some 
geological abnormality near the site. 
Maps giving the positions of the stations with sufficient 
accuracy for the purposes of the survey were not available. 
Astronomical methods had therefore to be used. The 
Government permitted free telegrams to pass at any time 
between the survey party and ihe Hobart Observatory, and 
the privilege was fully used to attain Greenwich time. The 
chronometer used in the survey proved deficient, but we 
believe that in no case was the estimated time in error by as 
much a3 twe seconds. 
