Scientists at Rice University, Houston, Tex., have developed a single instrument that can measure electrons and protons over the energy range of 50 to 100 000 eV. Code named SPECS (Switched Proton Electron Channeltron Spectrometer) the device is suitable for space missions because of its small mass (0.9 or 1.6 kg) and low power requirements (about 1 watt). 18‐point differential‐energy‐spectrum measurements for both electrons and protons include parts of the lower ends of the spectra that have been relatively neglected by plasma and penetrating‐radiation physicists.