He served under James Cook on his last voyage around the world , specialising in taking important astronomical readings using a sextant .
Captain James King FRS ( 1750 -- 16 November 1784 ) was an officer of the Royal Navy .
James King served under James Cook on James King 's last voyage around the world , specialising in taking important astronomical readings using a sextant .
Captain James King FRS ( 1750 -- 16 November 1784 ) was an officer of the Royal Navy .