< 35 1 ) 
The firft and fixth Columns of the preceding Ta- 
bles of Obfervations are copied from the Minutes as 
they were fet down at the Time. The Divifions of 
the Wooden Inftrument being not exaft, I found it ne- 
ceflary to make a Table to correct them by> which was 
done partly by meafuring with Compaffes, and partly 
by examining them againft thofeof another Inftrument 
The Corre&ions are every where to be fuhftrafted 
from the Angles obferved, and the Errors of a Degree 
and three Minutes and a half, occalioned by the mif- 
placing the fecond Speculum in all the forward Obfer- 
vations of September the ift, being of the fame kind* 
are joined with them, in the feventh Column of the Ta- 
bles of thofe Obfervations. The lafl: Column contains 
the Differences between the obferved Altitudes, cor- 
re£ted by the Aforementioned Table, and the Alti- 
tudes as they ought to have appeared by the Com- 
putations. Among them there are two or three which 
fo much exceed any of the reft, that for that reafon 
they feem to be rather owing to Miftakes, in counting 
the Minutes on the Inftrument, or the Time by the 
Watch, than to the Errors of the Obfervations. 
The greateft Part of the Altitudes were taken by a 
Elorizon not clear, of Land, and by that Means not al- 
ways fo readily diftin’guifhable. The Obfervers were 
all Perfons quite unaccuftomed to the Motion of a Ship 
at Sea, which in this Cafe was generally very great and 
quick, the Veffel we were in being only of about 60 
Tuns Burthen, as the Mafter informed us, the 
fmallnefs of which made it alfo more liable to be lifted 
up and let down again by the Waves : And if the 
Difference of Height occafioned by that Means was 
about four or five Feet, as we judged it to be y , it 
