[unkeptbarista]

Pretty sure the Greeks have all the materials for these.

Create batteries from dissimilar metals, using clay pots, weak organic acids, and copper wire. Once you have batteries, wind copper wire around a small, rough rod of iron to create a weak magnet.

A mineral acid will produce stronger batteries, but require access to things like salammoniac and blue vitrol and the knowledge of how to heat them together and pass the resulting gases through water.

[hbrav]

Copper _wire_ requires you to be able to draw wire, not just refine copper. I'm not sure if the ancient Greeks knew how to do that.

[unkeptbarista]

I'll admit that I was assuming that since many civilizations at that time knew how to make gold and silver filigree, that copper wire was also possible. One can probably replace the copper wire with gold wire, but you might have a hard time convincing the locals to loan you some for demonstration.