The instruments with which we have obtained our results are displayed at the Industrial Exhibition (in Moscow), and therefore I shall not describe them here. I shall state briefly the results of those investigations in the upper atmosphere which are related to the interplanetary medium and are therefore of interest to astronomers.

We made an attempt to measure corpuscular fluxes by means of the third sputnik. For this purpose we used as indicators two fluorescent screens made of ZnS (Ag) (2 x i o - 3 g cm-2), covered with aluminium foil of different thicknesses (8 x i o - 4 g cm-2 and 4 x io~4 g cm-2). There were three aluminium diaphragms 5 mm thick in front of screens 5 cm in diameter. Each diaphragm had a window for capturing all corpuscles with a solid angle of 1/4 steradian. The emission of the fluorescent screens was detected by photo-multipliers. The electrical signals so produced were transmitted to a storage device and then to the Earth by a radio-telemetering system.