[ 334 ] 
tliat the total duration will be fhortened by parallax 
no lefs than \t! 53'', fuppofing the fun’s parallax 
8'^, 7. and confequently that there might be ob- 
ferved a difference in the total duration between this 
place and Tornea° of 24' 33^^^: a difference confider- 
ably greater than was expected by Dr. Halley in 
1761 ; and, fuppofing with that affronomer, that 
the obfervations at each contact may be taken true to 
a fingle fecond, (which indeed experience will not 
warrant) fufficient to determine the fun’s parallax 
within -7-4-5-*'’ part of the whole. 
But as this and the other point fall in the great 
South fea, where it does not certainly appear that 
there is any land, let us enquire in what parts of the 
South fea we may reafonably expedl to find land. 
From the accounts of forne of the circumnavigators, 
it fhould feem that there are iflands fcattered here 
and there about the tropic of Capricorn, particularly 
the ifland or iflands of St. Peter, in about 150° of 
W. longitude from Greenwich, and in about 21° of 
S. latitude. I have therefore computed the paralladtic 
angle for a place 10'’ 22' 50'' to the Weft of Green- 
wich, and in 21° of S. lat. and find that the ingrefs 
will happen 6' 10'' later, and the beginning of egrefs 
6' 6" fooner, than if feen without parallax ; that 
the total duration is' therefore ftiortened 12' W' by 
parallax ; and confequently that there is a difference 
of 23' 56'' in the total duration between Tornea° 
and this ifland, fuppofing the fun’s parallax —8^', 7 on 
the day of the tranfit ; or of 26' 39'', if that parallax 
be fuppofed — 
About the latter end of the 16th century, Don 
Pedro Fernandez de Quiros made two voyages for 
the 
