C *7? ) 
III, T he Variation of the Magnetic al Compafs 5 ob- 
ferted by Capt. Rogers, Commander of the Ship 
Duke, in his Taffage from Cape St. Lucar in 
Calefornia to the Ifle of Guam or Guana, one 
of the Lad rones, with fome Remarks thereon 
Communicated by the. fame. 
H AVING lately had the Opportunity of pe- 
riling Capt. Woods Rogers' s original Jour- 
nal, who in 1709-10, in eight Weeks time traver- 
fed the great South-Sea , or Pacifick Ocean , I was 
highly pleafed to find the Care he had taken to fet 
down the Variations of the Magnetical Co?npafs in 
his Paflage from the South Cape of Calefornia to 
the Illand of Guana , being about feven Hours or 
10$ Degrees of Longitude* This might have been 
long lince expected from Capt. Dampier , who had 
three times made the Tour of the World, and thrice 
gone this very fame Track. 
It were to be wiiht that the French , who have 
had frequent Opportunities to do it, would bellow 
upon us an account of the Variations they have 
lately found 1 in their Voyages from Peru and Chili 
to China ^ and : that the Spaniards would tell us how 
the Needle varies at this time in the North Part 
of that great Sea, through^ which they return from 
the Manilla's to New Spain. With thefe helps, ha- 
ving three Points , in each Curve, we might be en - 
abled; 
