RESULTS OF THE VOYAGE OF H.M.S. PENGUIN - . 
355 
B. 
O. 
D. 
Standard compass . . 
O 1 
-0 26 
o / 
-0 32 
O / 
+ 4 2 
Fox compass .... 
+ 0 50 
0 0 
+ 2 20 
or nearly the same as off Baudin Island, and as the Dip corrected for horizontal 
forces in the ship differed only 10' from the normal, it was considered that the tables 
of correction for the three elements obtained off Baudin Island might for the purposes 
of this discussion be used for the observations over the “ magnetic shoal ” at Port 
Walcott, and this has been done. 
Although no direct observations of the mean Horizontal Force to north (or X of the 
Admiralty ‘ Manual ’) were obtained at the compass position where the Declination 
observations were made, still on comparing the best values of the Horizontal Force 
obtained on board with those on land, a small diminution was found, giving a mean 
force to north = ‘98 (considering the land force = l’O) at the Fox position. 
At the Standard compass position the mean force to north may be assumed as ‘97. 
Having so far defined the magnetic condition of the ship, we are in a position 
to review the order of observation at the magnetic shoal and consider the results. 
A preliminary examination of the general limits of the area of Disturbance 
at Port Walcott was made in November, 1890. The 22nd to the 25th of the 
following April were devoted to completing the magnetic survey of the shoal, the 
distribution of the observers being as follows :—Lieutenant Tancred, with a 
theodolite, was placed on Bezout Island, to take the true bearings of the Standard 
compass as the ship changed her position. Lieutenant Parry, on board the ship, took 
compass bearings of the theodolite station on Bezout with the Standard compass, 
the direction of the ship’s head being noted by Sub-Lieutenant Oliver. The Dip 
and Force observations were made by Lieutenant Combe, the position of the ship 
being fixed and depth of water taken at every magnetic observation. 
On the first day the ship was run across the area of disturbance in the north and 
south directions, whilst the observations of Declination were made, buoys being 
placed at positions of greatest disturbance. On the second day the Declination 
observations were continued over the eastern and western extremities of the shoal, 
special attention being given to the spaces between the buoy T s. 
The third and fourth days were occupied with observations of the Dip and Force 
with such additional observations of the Declination as could be made, the method of 
ensuring reliable results being as follows. The position of maximum disturbance 
had already been pointed out by the Declination observations; the ship was therefore 
moored in its immediate neighbourhood, one anchor being let go on the west side of 
the point of greatest westerly disturbance; the other anchor on the east side of the 
greatest easterly disturbance. Thus, by working the cables as requisite, the ship 
2 z 2 
