Original BS-1 Geiger counter representative of the earliest UV and X-ray counters flown in sounding rockets by the Naval Research Laboratory (NRL). It is a commercially manufactured version from the Anton Company working as a contractor to NRL and using the NRL design. Counters of this class comprise a gas filled tube with a cylindrical cathode and a wire anode in the middle. Photons of energetic radiation that enter the window at the end of the tube will ionize the filling gas making it electrically conductive. This will cause a discharge to flow between the anode and the cathode which results in a countable electrical signal. The effective wavelength sensitivity is determined by the transparency of the window and the nature of the quenching gas. This artifact is part of a collection of high energy detectors from the NRL (see Catalogue numbers 19880001000 through 19880017000). It was transferred to NASM in 1987. "BS" refers to Bureau of Ships.