What if one of the magnets were removed(example the N) would the beam still split? 
What if the beam started lower, if the beam, was closer the the S, would more mass go to the S, would there be a point, where it would not split anymore? How many people repeated this experiment?
Answer: In 1925 most people did not even believe there were electrons. There is no spin, no electrons. It is a radiation pressure. Seccond, there is no such thing as having an N one place and an S in anther place. they are apart of the same magnet. How the magnet is connected will affact the experiment, so it needs to be displayed how that is. It is possible the are from two different magnets, in which case there are also magnetic fields around the experiment.  Seccond in the regionN S, there is a tension, like a compressed spring. When the radiation leaves the mass, it is effected by the tension. This experiment proves electrons dont have a negative charge. They dont exist. Radiation, has a direct effect on magnetism, and this experiment, needs to be redone, and explored.