I have used several sources to check information, I must mention “Morsum Magnificat”, “The Vail Correspondent”, Tom Perera’s “Telegraph Collectors Guide”, Fons Vanden Berghen’s “Classics of Communications”, Greg Ulsamer’s “Faszination Morsetasten”, Herbert’s “Telegraphy”, Tom French’s “Bunnell’s Last Catalog”, The Eastern Telegraph Companies “Telegraph Engineering” books, Marilyn Albers and Jack Tod’s “Worldwide Porcelain Insulators”, W. Keith Neal´s “Searching for Railway Telegraph Insulators” and “Railway and Other Rare Insulators” and others, plus the help received from many colleagues, too many to mention, lest I forget some.

The possible errors contained in the descriptions of the items shown are entirely my own.