General Office, Washington, D.C.

The U.S. Post Office - Washington.

U.S. Post Office.

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

U.S. Post Office.

U.S. Post Office.

Post Office Building, Washington.

Model Room, Patent Office, Washington, D.C.

Model Room of Patent Office, Washington, D.C.

U.S. Patent Office,(South)

Patent Office.

Washington, the Patent Office.

New Wing, Patent Office, Washington, D.C., U.S.A.

Patent Office Court Yard, Washington, D.C.

Patent Office, Washington, D.C.

U.S. Patent Office.

The U.S. Patent Office.

U.S. Patent Office.

U.S. Patent Office.

The U.S. Patent Office.

U.S. Patent Office.

The U.S. Patent Office.

Washington, D.C., Patent Office.

The U.S. Patent Office.

U.S. Patent Office.

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

Interior, Patent Office.

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

U.S. Patent Office.

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