If carefully made, this little motor will reward its maker by running very nicely. Although it is of the utmost simplicity it demonstrates the same fundamental principles which are employed in real electric motors. *The Simplex Motor* is an interesting little toy which can be made in a couple of hours, and when finished it will make an instructive model. [Illustration: Fig. 243.—Details of the Armature of the Simplex Motor.] As a motor itself, it is not very efficient, for the amount of iron used in its construction is necessarily small. The advantage of this particular type of motor and the method of making it is that it demonstrates the actual principle and the method of application that is used in larger machines. The field of the motor is of the type known as the "simplex" while the armature is the "Siemens H" or two-pole type. The field and the armature are cut from ordinary tin-plated iron such as is used in the manufacture of tin cans and cracker-boxes. The simplest method of securing good flat material is to get some old scrap from a plumbing shop. An old cocoa tin or baking-powder can may, however, be cut up and flattened and will then serve the purpose almost as well. [Illustration: Fig. 244.—The Armature.] *The Armature.* Two strips of tin, three-eighths of an inch by one and one-half inches, are cut to form the armature. They are slightly longer than will actually be necessary, but are cut to length after the finish of the bending operations. Mark a line carefully across the center of each strip. Then, taking care to keep the shape symmetrical so that both pieces are exactly alike, bend them into the shape shown in Figure 243. The small bend in the center is most easily made by bending the strip over a knitting-needle and then bending it back to the required extent. [Illustration: Fig. 245.—The Field.] A piece of knitting-needle one and one-half inches long is required for the shaft. Bind the two halves of the armature together in the position shown in Figure 249. Bind them with a piece of iron wire and solder them together. The wire should be removed after they are soldered. [Illustration: Fig. 246.—The Field and Commutator.] *The Field Magnet* is made by first cutting out a strip of tin one-half by four and then bending it into the shape shown in Figure 245. The easiest way of doing this with accuracy is to cut out a piece of wood as a form, and bend the tin over the form. The dimensions shown in Figure 245 should be used as a guide for the form. [Illustration: Fig. 247.—The Bearings.] Two small holes should be bored in the feet of the field magnet to receive No. 3 wood screws, which fasten the field to the base. *The Bearings* are shown in detail in Figure 247. They are easily made by cutting from sheet-tin. Two small washers, serving as collars, should be soldered to the shaft as shown in Figure 243.