Today I started a new lab cycle on Charges and Fields. There are two experiments in it— Millikan’s famous oil drop experiment to measure the fundamental charge of the electron and measuring the Earth’s magnetic field. Both of them are quite simple ideas (observing how oil drops are deflected in a capacitor and watching the deflection of a current carrying wire respectively) but they are both difficult to carry out accurately and get good results. Also they are done in the dark.
I am doing the floating magic oil drop one. I have a vaporiser to squeeze in a spray of oil droplets between the capacitor plates, a power supply to adjust their motion and a microscope to squint in at the tiny tiny little floating dots.