Tracings of the positive ions--similar to other particle imaging methods. The positions and charges of indidual particles are recorded with graphite rubbings on paper.

From left to right we have:
(1) Postive charges in a fully saturate drawing field.
(2) The transformation of the uncharged particle into the first positive ion form.
(3) Motion of a single particle through space.
(4) A local cloud of positive charge.

Next from the electricity lab is the creation of a symbolic voltmeter.