In the Proceedings of the Royal Society of Edinburgh for 1921–22 Whittaker suggests an atomic model designed to absorb and emit radiation by quanta. This model consists essentially of a system of radial magnets, set as the spokes of a wheel with like poles (say south) at the centre. The electron approaching the wheel along the axis of symmetry will, according to the author, set the wheel into rotation, giving a “magnetic current.” The action of the approaching charge, giving a rotation to the North Pole and a “magnetic current,” is quite the analogue to the North Pole approaching a non-axial electric charge, setting it into rotation, and producing an “electric current.” The electron, with energy exceeding a definite value, succeeds in going through the atom, with the result that a definite amount of energy is permanently transferred from the electron to the atomic wheel, a result which resembles the absorption of electronic energy by the atom in spectrum excitation.