for things about our size, we generally use two beginning points that everybody knows about, and then we measure from those points to the thing we want to give a location. we might start with the plymouth rock and the blarney stone. we could then say, "captain smith's ship is 1400 miles from plymouth rock going toward the blarney stone." or, in another case we might say, "captain jones's ship can be found by drawing a line from plymouth rock to the blarney stone, finding a point 700 miles along this line from plymouth rock, taking a left turn of 90° upon reaching this point from plymouth rock, and then traveling an additional 90 miles.