When I think of persuasive I think of someone convincing another person to do something.
It is difficult for people with arthritis of the kness to A. Genuflect.
Sometimes he whirled down the incline of a wave as if he were on a hand sled.
The man is clearly in a context of desperation or at least difficulty, stuck out at sea on a life preserver. The imagery brings one of a childlike delight or a fun situation. However that is contrary to the actual situation. The man clings to a life preserver, trying to survive, not have fun, but nature rolls on, indifferent to this man's plight.
The final stanza of "A Poem for Mrs. Long, My Librarian" indicates that books gave the speaker comfort and hope during her childhood. Just before this stanza, the reader states that her everyday life is fine, but in this stanza, she informs the reader that books still provided an escape to somewhere more magical than her own world. In the final line, the speaker discusses how her librarian, and the books she shared, were a source of "Spring"(hope) for her.