A telegraph relay, used as a signal amplifier in long-distance circuits, is often referred to as a "pony relay."
The base is cast iron, topped by a wooden plate. Two induction coils with steel covers are attached to a brass frame. Stamped into the wooden plate is the information: "W.U. Tel Co, Morse relay 4-B, 150 ohms."
Please post your comment below to share with others. If you'd like to privately share a comment or correction with MMN staff, please use this form.