Standardizing rubber-covered wires and cables

The effect of the tendency toward high electrical pressures is nowhere more severely felt than in the requirement for insulated wires and cables, for insulation practically controls this feature of electrical distribution. Electrical pressures can, to be sure, be increased to almost any extent, and electrical energy be transmitted to almost any distance; but to control its pathway, to regulate its course, to prevent waste, and maintain safety, this is the problem — the big underlying problem — of all electrical distributions of to-day. Five hundred volts and under are easily controlled; but pressures of 5 000, 10 000, or 20 000 volts introduce new problems, problems that were not even thought of in the days when 110 volts were considered standard practice.