How did the Royal Commissioners of the London Board of Trade establish the end points of the northern border of New Jersey in the year 1769 ? i.e. How did they determine the latitudes of that border-line's intersections witht the Delaware and Hudson Rivers ? (...which I believe are at approximately 41 degrees/21 minutes and 41 degrees/zero minites, respectively...) Earlier attempts to set that boundary had produced an approximately parallel line about 10 miles farther north: from 41 degrees/40 minutes on the Delaware to "...the mouth of Tappan Creek..." on the Hudson.