LOCAI. ATTRACTION' OF THE BAFFIN". 95 
The process I employed for determining 1 the 
Baffin’s deviation, I might add, could be easily 
practised in any ship for the same purpose, when 
lying in a river, bay, wet-dock, or other situation 
where the water was smooth. All that would be 
requisite for supplying the want of a crow’s-nest, 
would be to rig a temporary stage of studding- 
sail booms or planks, on the middle of the main- 
topgallant-mast, where there would be no fear of 
deviation; and on this stage, observations for de¬ 
termining, by comparison, the error of the bin¬ 
nacle-compass, when the ship’s head was in diffe¬ 
rent positions, might be easily made. When, 
however, a very distant well-defined object can 
be seen from the place occupied by the binnacle- 
compass, perhaps a simple set of observations on 
its bearings, with the ship’s head on every point 
of the compass, is the most easy of all other me¬ 
thods for obtaining the deviation. But there arc 
few cases in which the bearings of such an object 
could be accurately determined by the compass in 
the binnacle, because of the difficulty and indeed 
impossibility of employing the sight-vanes while 
the compass is uuder cover, and because of the 
liability there is of the deviation being changed,, 
by merely removing the compass out of the bin¬ 
nacle, though it be placed within a foot or two of 
its proper position. 
