Think about the life situations and attitudes of Ada and Henry and how they contrast. Ada feels trapped by the circumstances of her life as a poor farmer's wife in the South. Her desire is to find a way to get away, to flee the farm and her husband and everything about her life in that place. Her method of attempting to achieve this desire is to murder her husband - three times - but she still finds herself trapped on the farm in the South. Whatever she does, she will "never get where she wanted to go." The pump keeps running dry and there's never enough water for her life.
Henry, on the other hand, is constantly traveling, never truly putting down roots anywhere, carrying with him the memories of his wife and the awareness that he can be content with whatever life brings him, wherever he is. He's not trying to achieve something bigger or better, he's not looking for an escape from his existence - "He was always where he was going." For Henry, being fully present in the moment is enough. Pumps can be repaired and made to work again.