U.S. Patent Office, Washington, D.C.

U.S. Patent Office.

U.S. Patent Office, Washington, D.C.

Patent Office.

Patent Office.

U.S. Patent Office. Front View.

Interior view. Patent Office.

Interior view. Patent Office.

Patent Office.

South Hall of Patent Office.

Patent Office, Washington.

New Wing, Patent Office, Washington, D.C.

Model Room of the U.S. Patent Office.

Portico, South Front.

Patent Office Corridor.

Patent Office Corridor.

The Patent Office - Washington.

The Patent Office - Washington.

The Patent Office - Washington.

Patent Office, Washington.

Patent Office. Interior.

Patent Office, U.S.

Patent Office.

Patent Office, Washington.

The Model Room in the U.S. Patent Office.

Interior of the Patent Office, Washington, D.C.

Grand Staircase, Library of Congress, Washington, D.C., U.S.A.

Grand Staircase, Library of Congress, Washington, D.C., U.S.A.

The magnificent new Congressional Library - most spacious of book repositories-Washington, D.C., U.S.A.

The magnificent new Congressional Library - most spacious of book repositories-Washington, D.C., U.S.A.