Baghdad Batteries
The Baghdad Battery or Parthian Battery is a set of three objects: a ceramic pot or glass jar, a tube of copper, and a rod of iron. Fill the jar with an acidic liquid, such as vinegar or fermented grape juice, and you have yourself a battery capable of generating a small current. The acidic liquid permits a flow of electrons from the copper tube to the iron rod when the two metal terminals are connected. This small electric current is used in electroplating, and medical devices.
Electroplating
Medical Devices
The Telegraph
The knowledge for the telegraph is possible and is used within a few small applications. There are telegraph lines within the two sets of fortifications in the capital, Eadwald. They use banks of Baghdad Batteries to power the system. It works but it in not robust.
No one has tried to do a long-distance telegraph line yet.