Sentence:  The dweller at p is last to hear about a new cure , the slowest to announce to his neighbors his urgent distresses , the one who goes the <WSD>farthest</WSD> to trade , and the one with the greatest difficulty of all in putting over an idea or getting people to join him in a cooperative effort . 
Meaning of the word marked with <WSD> tags:  to the greatest distance in space or time (`farthest' is used more often than `furthest' in this physical sense)