[en] A general purpose streamer chamber facility is described. The multiplicities and momenta of charged particles are determined in the central region of the chamber over a solid angle of about 0.85 . 4π. The remainder of the visible volume is devoted to π^+-/e^+- separation and to π/sup o/ and gamma ray detection. The former is achieved by observing electromagnetic shower development and the latter by measuring both the conversion point of each primary interaction gamma ray and the momentum of each shower track produced in an array of coaxial lead-oxide plates. There are 9 such plates, spaced 8 cm apart, and the plate thickness is 0.6 radiation lengths. Separation of π^+-/e^+- is effective above 250 MeV/c, and gamma ray detection is practical above 100 MeV by this method. The solid angle of the lead-oxide shower detector is about 0.5 . 4π. Muons above about 1 GeV are distinguished from charged hadrons by a single layer (which gives three track coordinates) of multiwire proportional chambers that determine whether a given particle has interacted strongly in the coils or flux return plates of the magnet. This ''external muon identifier'' also subtends a solid angle of about 0.85 . 4π. Good separation of π/K, K/p, and π/p is obtained by ionization below 0.7, 1.0, and 1.4 GeV/c, respectively, and useful separation (about 1.6 standard deviations for π/K, 0.7 standard deviations for K/p, and 2.2 standard deviations for π/p) is achieved in the region of the relativistic rise in ionization. The ionization measurements are supplemented by time-of-flight, which is effective for π/K, K/p, and π/p at momenta up to 1.0, 1.7, and 2.0 GeV/c, respectively