Extra^ of a Letter of Mr. Heathcott to Mr^ Flam- 
fteed from Cabo Cors Caftle on the Coajl of Gui- 
ney /i'e 14/^0/December \ 6%":^. concerning the 
Tide on that CoaU , Variation of the Needle, 
isrc. 
THe Sea runs here along the fhore continually to the 
Eaft'ward^ at a very great Rate, except at/«// and change^ 
for then it runs to WeHward^ or at leaft maVes agreat 
'Ahate, November 24 th. I took the time of the High-water at 
the CaBle ( as near as I could) at 3 h. 30' p. m. It flerwed a- 
bout 6 foot. The Magneticd Variation hcre is ^ ° 49 from ths 
^orth to the Weffward. At my firft Arrival I fixt my Weather- 
Glafs^ and found the Jrgentum ^ivum to Afcend 29 Inches, and 
in a Tornado 29 j ^ Inches • But a Stranger by Accident broke the 
Cane, fo that I could make no further tryal, &c. 
Martmi 
