APPENDIX. 
521 
On ship-board.'] 
occurred whilst beating along that part of the south' coast of Terra Australis 
discovered by the French, where the dip is nearly 67*; and that it may be 
seen how near the bearings coincided with the azimuths and amplitudes, 
the differences which should result from the common multiplier and sines 
of the angles are added to the table. 
Before tacking. 
After tacking. 
Increase of B.Var. 
Objects set. 
Bearings. 
Ship’s 
Head. 
Bearings. 
Ship’s 
Head. 
From 
Bearings 
From 
Multipl. 
C. Jaffa, outer part 
C. Lannes, the point 
N. 4°W. 
S. 32 E. 
E. S. E. 
N. 9°W. 
S. 40 E. 
S. W.byW. J 
6 ° 30' 
5° 53' 
Hummock 
Furthest extreme 
N. 35 | E. 
S. 36 ‘ E. 
S.E.byE. 
N. 33± E. 
S. 44" E. 
S.W.byW.j 
5 0 
5 34 
C. Lannes, north extreme 
Furthest extreme 
N. 39 E. 
S. 51 E. 
S.E byE. 
N, 30 E. 
S. 55 E. 
West. 1 
6 30 
6 8 
C. Lannes, western part 
Sandy hummock 
Furthest extreme 
N. 15 W. 
N. 19 E. 
S. 53 E. 
E. N. E. 
» 
N. 21 W. 
N. 15 E. 
S. 61 E 
S.W.byS. | 
J 
6 0 
4 57 
The sandy hummock 
Projecting’ part of t he coast 
N. 12 W. 
S. 59 E. 
East. 
N. 18 W, 
S. 64 E. 
S. W.byS. } 
5 
5 30 
5 13 
Mean increase 
5 54 
5 33 
Another example occurred whilst working up to King’s Island, in 
Bass’ Strait, where the dip is 68 ° ; on changing the ship’s head from 
West to S. E. ~ S., the decrease of east variation from five bearings was 
4° 48' ; from the common multiplier it would be 5° 33'. 
The bearings therefore showed differences the same way, and nearly 
the same in quantity as did the azimuths and amplitudes : that f hey should do 
so exactly, is not to be expected ; for if azimuths, and especially amplitudes 
taken at sea with the present compasses, cannot be depended upon nearer 
than to half a degree on either side, as I believe they cannot, even under 
the most favourable circumstances, the best bearings set by hand are likely 
to err a degree on either side, and two degrees where there is much 
VOL. II. $ X 
I 
