C 21 9 ] 
but generally have taken a medium of, from fix to 
ten, or more. 
I cannot help taking notice of what furprized me 
greatly, viz. that I fhould always find the variation 
lefs at anchor, in the Weft-India Blands, than at 
fea, though near the fame fpot. As for inftance, 
June 1 8, 1760, three leagues fouth Prince Rupert’s 
Bay, Dominico, I found the variation, by a medium 
of five azimuths and an amplitude, to be 5 0 27' E. 
And in the Bay itfelf, June 20, by three azimuths 
and an amplitude, it was 3 0 27' j and on the 22d, 
by fix azimuths and amplitude rrr 3 0 1 2' E. The 
medium of thefe is 3 0 20' E. full 2° 7' lefs than in 
the offing, though but nine miles off. 
The fame phasnomenon appeared, upon experi- 
ments repeated March the 23d, 1761, when in the 
fame Bay, the medium of eight azimuths gave 
3 0 19' E. Off of Antigua, and at anchor in Saint 
John’s Road, the fame thing was obferved, though the 
difference was not fo great. Thefe things exercifed 
my thoughts, though I muff own I could not hit on 
any folution that pleafed myfelf. I am, 
S I R, 
with great truth, 
your very humble fervant, 
David Rofs. 
Ff 2 
A Table 
