This is the American Rocket Society's ARS Rocket Motor No. 4. It was used in the flight of ARS Rocket No. 4 in 1934 at Marine Park, Great Kills, Staten Island, New York. The rocket went up to 382 feet and flew about 600 miles an hour.
The motor used gasoline and liquid oxygen. The ARS intended to fly their ARS No. 5, but there were technical problems which prevented the flight and the ARS decided that more could be learned about rocket motor design and performance by static tests. ARS No. 4 was therfore the Society's last flight rocket. This object was donated to the Smithsonian in 1966 by the American Institute of Aeronautics and Astronautics.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.