Carbon Contacts

Abstract

THE contact difficulties to which I referred were those of fifty years ago with light or hesitating contacts backed by insufficient volts. I did not intend to imply that at the present time with new materials and abundant volts contacts need give any trouble. I have for a long time recommended Acheson graphite made at Niagara, from which all other matter has been volatilised, and this, I expect, is what Mr. Turnbull has used. There are also the more modern mercury in nitrogen contacts which are admirable where the larger movement necessary to operate them and the slight time delay do not matter.