186 
A VOYAGE TO 
[South Coast. 
1802. The variation observed on shore, with the theodolite, was 5 0 48' east. 
Tuesday 6. w ith azimuth compass, No. I. - 2 58 
For this difference between the instruments, I find it difficult to 
account satisfactorily ; but it is the same way, and nearly similar in 
quantity to what was observed in Lucky Bay. The true variation 
on board the ship, deduced from azimuths taken at anchor two miles 
to the north-east, and using the compasses No. 1 and 2, was as before 
mentioned, 4° 13', nearly the mean of the above; but the bearings 
taken with the theodolite at Kanguroo Head and Prospect Hill 
showed only 2-|° east, as compared with the bearings on board the 
ship. There can be little doubt of the existence of magnetic sub- 
stances in the lands about here, more particularly, as I think, in 
Yorke's Peninsula ; and there will presently be occasion to notice 
more instances of their effect. 
The approach of the winter season, and an apprehension that 
the discovery of the remaining unknown part of the South Coast 
might not be completed before a want of provisions would make it 
necessary to run for Port Jackson, prevented me from stopping a day 
longer at Kanguroo Island than was necessary to obtaining rates for 
the time keepers; and consequently, from examining the south and 
west parts of that island. The direction of the main coast and the inlets 
it might form, were the most important points to be now ascertained ; 
and the details of particular parts, which it would interfere too much 
with those objects to examine, were best referred to the second visit, 
directed by my instructions to be made to this coast. When, there- 
fore, the rising of a breeze made it advisable to get under way from 
Kanguroo Head, which was not until two in the afternoon, we pro- 
ceeded for the eastern outlet of the Investigator's Strait; in order to 
prosecute the discovery beyond Cape Jervis. 
The wind was at south-east ; and the tide being against us, 
but little progress was made until the evening, when it became favour- 
able. Our soundings were irregular, and some rocky islets being 
