Already noticed in the preceding pages, and the following:
Fig. 26
8. The Electric Spinner ([Fig. 26]).—A toy full of instruction. The standard is a steel magnet which produces a magnetic field. Inside of this is an electro-magnet which serves as an armature. Plainly visible on its shaft is a commutator to which the electric current from a dry cell is sent. This causes the armature to revolve and carry with it a series of colour disks which may be adjusted so as to show what tint or shade results from mixing colours in various proportions.
Fig. 27
