No. These early phone systems were "Magneto", not the modern "Central battery" (CB). Each subscriber had their own batteries (No. 6 cells), so there was no DC

No. These early phone systems were "Magneto", not the modern "Central battery" (CB). Each subscriber had their own batteries (No. 6 cells), so there was no DC on the line. There was Ring Current of course, but that has always been well above 50 Volts.