Some former police and fire buildings are contributing properties to that and other districts. Four of the properties listed have, or have had, a military purpose. The original Fort Orange, built by the Dutch colonial authorities of New Netherland, defended the fledgling settlement. In the late 19th century, the state built the two armories for the National Guard. The "Slater" was commissioned by the Navy for service in the Pacific theater of World War II; it was later sold to the Greek Navy, where it was rechristened the "Aetos". Government entities also control the four buildings used for educational purposes. Three are used for administrative purposes—the Old Albany Academy Building, originally a private school, is the City School District of Albany's main offices, the former headquarters of the Delaware and Hudson Railroad is now the main administration building for the State University of New York (SUNY) system and the State Department of Education Building is home to that agency, which oversees public education in the state. The James Hall Office building has been annexed to one of the city's elementary schools, later used for a Montessori school. The former Philip Livingston Magnet Academy, now converted into senior apartments, is the only purpose-built public school building listed so far in Albany. Two former public school buildings are included as contributing properties in the South End district, and the former St. Joseph's Academy is a contributing property to Arbor Hill. The Harmanus Bleecker Library, originally built by the city as its first library but now redeveloped privately as office space, is one of eight properties with a past or present cultural function. Of the other seven only two, the Albany Institute of History & Art and the Palace Theatre, are purpose-built for their continuing role. The Institute, the city's major museum, is joined by three historic house museums and the "Slater" in that function. Lastly, the Washington Avenue Armory is now used for some concerts. Contributing properties to the historic districts with cultural functions include the John A. Howe Branch library in the South End. Three properties also commemorate scientific discoveries and technological accomplishments. As a professor at the Albany Academy, Joseph Henry discovered electrical inductance, which would later lead to the development of the telegraph and all subsequent information technology. The building has since been renamed in his memory. James Hall made many of his paleontological and geological breakthroughs from the research in his office and laboratory. While Squire Whipple was an Albany resident whose bowstring truss bridge design was based on his own mathematical studies of the stresses on bridge trusses, work which helped move bridge building from a craft to a science, he did not have anything to do with the construction of the bridge that shares his name.