NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Lars Bergman
Date: 2024 Apr 11, 12:07 -0700
Kermit, you asked "were the Greenwich coordinates of Eclipse Island published then?".
In Tables Requisite, 2nd edition 1781, table XX gives "Burgeo (Isles) 47°36'20" N 57°36'30" W". The longitude is also given in time as "3h50m24s W". As you see there is a 2s, or 30" difference beween the longitude values in arc and time.
In The British Mariner's Guide from 1763, containing "A sett of Correct Astronomical Tables", table XXXV gives longitude of different places but the nearest place I can find is "St.John's Fort 47°32' N 52°48'15" W". Here the longitude in time corresponds to the arc. This fort is probably identical to Fort William, according to Wikipedia in use 1700-1871 and having a (modern) longitude of 52°42'2". So the longitude of this fort was probably known to Cook in 1766.
Another interesting observation in this Guide is table V giving the semidiameter of the sun. For 5 August it gives the value 15'52", five seconds larger than Frank's NA.
Lars
