The author in criticizing the manufacturer of some cable with 600 mils insulation between conductors because the manufacturer had been satisfied with a dielectric strength test that was limited by cable bell trouble, attempted to make a dielectric strength test on a 15-foot sample, carrying the pressure to 212 kv. between conductors. In this case also the pressure was limited by cable bell trouble and there was no failure of the cable within the lead sheath. Assuming that the dielectric strength of impregnated paper insulation also varies with the square root of the thickness, and using this particular point as our starting point, then we get the curve shown by B in Fig. 20. On the same sheet are also shown two points given by Weiset in the E. T. Z. for January 15, 1920, also six points given by Fernie in Beama for September, 1921, and also one figure giving results from an Italian cable, the latter data being obtained from private sources. On the same sheet are also shown the results of a large number of dielectric strength tests on various thicknesses of insulation made for the author on cables purchased in the last three years. For those thicknesses of insulation where a large number of tests are available, these results show a ratio of maximum to minimum greater than 2 to 1.