Compressed gas insulation for electric power transmission

It can be claimed that gases at elevated pressure are the logical and, perhaps, inevitable, replacement for atmospheric air as the primary insulating medium for transmission of high-voltage power. Such compressed gas-insulated lines would reduce or eliminate most of the problems of open overhead lines, i. e., the inadequate insulating strength of air at 1 atm, corrosive contamination of insulators, exposure to lightning, radio interference, need for extensive rights-of-way, and the alleged unsightliness of overhead lines.