The address concerns itself with the transmission of electrical power in bulk underground principally at the voltages of 132 kV and higher. It states the basic problems of an underground system starting from the needs of the usual tortuous route and ending with the rating and high cost difficulties. There follows a review of current approaches setting these against the historical background. First, it concentrates on the severe mechanical difficulties of producing High grade cable Insulation, with paper as an Insulant, In an extremly flexible form, goes on to describe the special nature of the accessories needed to solve the electrical and pressure-retaining requirements and then deals with the many special rating solutions which are now being adopted to meet the growing demand for high MVA circuits. Bearing in mind the high relative cost of high-voltage cable much research and developement work has been in the field of the economy and the address makes reference to the many approaches. An approach is made to the problem of a transmission system which, ab initio, needs to be visualised as largerly underground and points out the strong case for d.c. transmission.