A book almost 5 decades overdue was returned to the San Francisco Public Library. On Dec. 9, 1970, the copy of Eldridge Cleaver's memoir "Soul On Ice" was due, making it 47 years, four months and 29 days late. The fine would be $1,731.70, if the library didnt cap it at $10.01. The paperbacks cover is ripped off and there is a hole in the title page. The branch manager said she'd like to know who the library patron is so she can get the story behind the returned book.