344 Mr. Harvey’s experimental inquiries relative to the 
stations only, were the measures of the magnetic influence 
found below that of the earth ; and in the larboard stations, 
the whole of the results were found much below. If the 
mean of the five intensities in the latter section be denoted 
by 10, that of the corresponding stations in the middle sec- 
tion will be 12.6, and of the starboard 16.3* 
The magnetism arising from position is, it is well known, 
of a very variable kind ; developing its intensity in some 
situations of an iron mass, with singular energy and force, 
and in others exhibiting only an action of the feeblest kind. 
Those changes also, manifesting their influence in an instan- 
* The following observations made by Captain Moorsom, on board the Ariadne, 
in Simon’s Bay, at the Cape of Good Hope, will exhibit the anomalous results of a 
dipping needle when employed on ship board. 
Experiments performed in the After Cabin. 
Larboard Side. 
Amidships. 
Starboard Side. 
Station, 
b" 
&' 
B" 
Dip, 
5 1° 55' 
52° io' 
5 *° S' 
In the fore cabin, at the station S" amidships, the dip was found to be 47° 47'. 
On the quarter-deck, at the station f', between the binnacle compass, and on the 
stand for the azimuth compass, it was found to be 48° 15'. 
In the after cabin at the station 0 " amidships, the dipping needle showed 59*25', 
when placed in a plane inclined 45 0 to the magnetic meridian ; but in the fore cabin 
at the instrument with the same azimuth gave only a result of 56° 15'. 
In the stern sheets of the barge, on the booms, the dip was found to be 50° 22^'. ! 
The dip determined in a house in Simon’s Town, distant thtee quarters of a mile ' 
from the ship, was 48° 23'!, agreeing within 8'J of that determined between the j 
binnacles. 
The latitude of the ship was 34 0 1 1' 38" S., and longitude 18° 28' 35" E. j 
Variation 28° W. 
