On and near land.] 
APPENDIX. 
527 
Near the west side of Yorke’s Peninsula, the corrected cast variation 
was 3° less than on the east side, although the places of observation were 
not more than forty-eight miles asunder : the uncorrected observations 
differed 6°. 
Upon the east side of the high hills behind Memory Cove, the cast 
variation was 1° 40' greater than at the granitic summit of the same hills. 
In Shoal -water Bay, at anchor near the eastern shore, the corrected 
east variation was 1° 25' less than near the west shore ; at Broad Sound 
also, it was 1° less on the east than on the west side. These effects were 
correspondent to the former, though the expression of the situations be 
unavoidably different. 
In the Investigator’s Road, Gulph of Carpentaria, the east variation 
was full 1° more on the east side of Bentinck’s than on the west side of 
Sweers’ Island. The rock here is partly iron ore. 
Near the east side of Pellew’s Group, the east variation appeared 
from the bearings to be increased 2° from what it had been at a further 
distance, though in regular course it should have diminished ; and at 
stations on the east sides of the different islands, I found it necessary to 
allow 1° degree more than on the west sides. 
There were several other examples where the south end of the 
magnetic needle was drawn towards the nearest land ; but only two where 
the contrary attraction seemed to have been exerted. These were both 
on shore, and probably might not be exceptions to the rule if all the 
circumstances were known ; for although the body of an island may lie to 
the west, a single block of stone near the theodolite on the other side might 
do more than counteract the opposite attraction. 
To arrive at the cause why both the iron in the ship and also the land 
should preferably attract the south end of the compass needle in the 
southern hemisphere, it seems necessary to refer to the direction of the 
dipping needle ; for the unobstructed magnetism in a mass of iron will lie 
as nearly in that direction as the form of the mass will admit. Where the 
south end of the needle dips 60°, the north end will necessarily be no 
more than 30° from standing perpendicularly upright ; and it is to be 
supposed, that the upper ends or parts of the different pieces of iron 
in the ship will possess the same attraction as the north end of the dipping 
