Rising behind the First Officer's Quarters is the Optical Tower built in 1918-19 to calibrate optical equipment, particularly range finding instruments, made in the Yard. From the tower, sightings were taken on the United States Capitol, the Washington Monument, and the Masonic Temple in Alexandria, ten miles away.
Second Officers House
On October 10, 1801 the Navy Department contracted the firm of Lovering and Dyer to build a house for the second officer and the officer of the Marines. The two-and-a-half-story brick house was constructed around a farmhouse already on the property when it was bought in 1799, making it the oldest building in the Yard. The back of the wooden farmhouse can still be seen as it interrupts the brick wall that was once the eastern boundary of the Yard. It is not known who lived in the house before 1814, but for most of its history it has served as quarters for the second officer. The house has been added on to over the years and the last of these additions was completed prior to 1868. It now serves as the home of the Commandant of the Naval District of Washington.