SHAWN MILLER

In 1888, Ainsworth Rand Spofford, the sixth Librarian of Congress, detailed his vision for the public reading room in the new Congressional Library — now known as the Thomas Jefferson Building. The space should follow the example set by the British Museum Library and be “circular or octagonal in form, so that all parts of it may be commanded” from the center.

To realize this “panopticon” concept, Spofford provided specifications for a “massive circular desk” that would give librarians and the Main Reading Room superintendent a view of every researcher, the card catalog and each alcove representing a major realm of knowledge.

Meanwhile, from the eye of the room’s domed ceiling, the figures in the aptly named painting “Human Understanding” could monitor the books springing forth from conveyor systems that connected the control room under the central desk to the stacks, the Capitol and eventually the John Adams Building and beyond. In her memoir “Thirty Years in Washington” (1901), Mary Cunningham Logan, the widow of Sen. John A. Logan, called the entire process — identifying, requesting and delivering books — a “marvel of ingenuity.”

Since that observation, the ingenious process has changed. The computer catalog replaced the card catalog; Electronic Book Paging phased out the call slips sent by pneumatic tubes; the book carrier pulled by continuously moving chains ceased operation, as did its replacement — a specialized elevator that lifted books from the control room into the reading room.

The tunnel to the Capitol, which once allowed the quick transport of materials to members of Congress, closed prior to the construction of the Capitol Visitor Center. And, the Library began providing content online, allowing researchers all over the world to access its digitized collections. Still, the mahogany central desk remains a powerful symbol — a direct connection between knowledge and its seekers and the never-ending quest to deepen and expand all human understanding.