The paper deals with flashover in oil between electrodes mounted on pressboard sheets; puncture and flashover of precompressed board; flashover in the presence of stress normal to the pressboard surface; breakdown between covered conductor in contact, or separated by packing pieces, or separated by barrier sheets; flashover of an interrupted surface; and flashover between electrodes passing through bushes in a pressboard sheet. It also contains comparative data on breakdown voltages at room temperature and at 90°C, in elected arrangements.