What machine did ampere invent to measure the current going through a wire?

Ampere invented a instrument utilizing a free moving magnetic needle, otherwise known as a compass, to measure the flow of electricity. This was done in 1820, and it was actually found by accident (at first)! He then conducted experiments, making him the first person to develop measuring techniques for electricity! I hope this helps! ~Mia

Good for willis. what’s a stud.