TOO Difficulties in taking the Variation. 
y^«.^699. at the Cape (from which I found my felf 
not Leagues diftant) was then com- 
puted, and truly, about 1 1 Deg. or more : 
And yet a while after this, when I was got 
I o Leagues to the Eallward of the Cape, I 
found the Variation but lo Deg. 40 Min. 
W. whereas it fhould have been rather more 
than at the Cape. Thefe Things, I con- 
fefs, did puzzle me : neither was I fully 
fatished as to the Exaftnefs of the taking 
the Variation at Sea: For in a great Sea, 
which We often meet with, the Compafs 
will traverfe with the motion of the Ship ; 
bcTides theShip may and will deviate feme- < 
vviiat in Steering, even by the beft Helmf- 
men : And then when you come to take an 
Azimuth, there is often fome difference be- 
tween him that looks at the Compafs, and 
the Man that takes the Altitude heighth 
of the Sun ; and a fmall Error in each, if 
the Error of both fhould be one way, will 
make it wide of any great Exaftnefs. But 
what was moft fhocking to me, I found 
that the Variation did not alwavs increafe 
or decreafe in proportion to the Degrees of 
Longitude Half or Weft ; as I had a No- 
tion-they might do to a certain Number of 
Degrees of Variation Eaft or Well, at 
fuch or fuch particular Meridians. But 
finding in this Voyage that the Difference 
of Variation did not bear a regular pro- 
portion to the difference of Lortgitud ■, I 
Vv as 
