How do you make a homemade telegraph made with magnetism?

To make a homemade telegraph using magnetism, you'll need a battery, a small electromagnet (made by wrapping insulated copper wire around a nail), a switch, and a simple circuit. Connect the battery to the switch and the electromagnet, ensuring the switch can open and close the circuit. When you close the switch, electricity flows through the wire, creating a magnetic field that can attract a nearby metal arm or lever to tap on a sound-making device, like a bell or paper. By opening and closing the switch, you can send Morse Code messages through the system.