…A History of the Highland Park Public Library
The Library made additional changes to service in the first decades of the 1900s. It converted to “open shelves,” allowing library users to walk into the book stacks and select their own books. Prior to that time, patrons called for a book by writing its shelf location number on a slip of paper, which was handed to the librarian. The term “call number” is still used to refer to a book’s shelf location.
Another change for the Library was the addition of a telephone around 1915. This allowed residents to contact the Library from their homes (if they had telephones). In 1915 Highland Park had around 5,000 residents, but only about 1,000 had telephones.