Discovery of the Electron

a primitive television picture tube:
- electrons boiled off of a hot filament

attracted to a plate at +2500 volts

           ...some electrons pass through a hole in the plate, coast to a fluorescent screen,
making a bright spot
where they hit






using this apparatus, Thompson discovers electrons
magnetic field bends "electron" beam at right angles
...North one way, South the other ........
...right hand rule, inherently 3-D