Rubber insulation

There is little question that GR-S was used in electrical insulation that was sufficiently satisfactory to carry us through the war, and without which we would have been seriously handicapped. It is also a foregone conclusion that eventually an adequate supply of natural rubber will be available. This raises the question of the extent to which either or both of these two materials will be used as electrical insulation when free markets again exist. It is perhaps timely to discuss the relative merits of these two materials and to try to appraise their future usefulness.