distribution, &c. of the magnetic intensity in ships of war. 337 
the intensities at the stations and vf. The intensities at and 
abaft the point 17 ', possessed intensities greater than the as- 
sumed terrestrial intensity ; and from that station to the 
forecastle, the magnetic influence was found to be less. 
In the same section on the main deck, the intensity in- 
creased from 97.90 to 108 . 47 , in the short interval from «' 
to / 3 ", in consequence of the iron tiller, which was below the 
deck, and immediately in the plane of the section. At the 
station y" the intensity underwent a small declension, and at 
a still farther decrease, the south pole of the oscillating 
bar dipping towards the extremity of the tiller, the station 
being over it. At e" the intensity again increased, after 
which it declined progressively to jf l , the last point in the 
section it was possible to examine. 
On the lower deck, and in the same vertical plane, it was 
remarked that the intensity at y" was very nearly the same 
as at the corresponding station on the main deck. At the 
points e" and f the attractive influence increased, but di- 
minished at the stations & lr and ad". At this point also the 
north pole of the oscillating cylinder was drawn five degrees 
below its horizontal direction ; an effect produced by the 
proximity of the station to the after part of the shot-locker. 
At the station a'", over the central tank, the intensity increased 
to 118.97 ; but at a "", immediately below the last mentioned 
station, and only twenty inches above the surface alluded to, 
the intensity was less by the quantity 16 . 33 . At f the 
attraction again declined ; but at y ", nearly over the foremost 
extremity of the tanks, attained to 128 . 15 , its maximum. 
In the starboard section, on the upper deck, the least in- 
tensity was found at F', in the same transverse vertical plane 
mdcccxxiv. X x 
