Field Museum librarian, veteran

If William Peyton Fawcett could not find something in the Field Museum's library collection, it simply wasn't there.

The head librarian for 27 years, nearly every item in the library had passed through his hands at one point or another, his friend and predecessor Benjamin Williams said.

Mr. Fawcett's intimate knowledge of the collections came from reclassifying the entire library when they switched from the Dewey Decimal to the Library of Congress Classification that begin in the 1940s.

"Nobody will ever know as much about the collection as he did," Benjamin Williams said.

But an item that had belonged to Nathan Leopold, an avid bird watcher and collector …