SELECTIVE TYPE.--The second method, the _selective_, enables the operator to select any speed at will, and in doing so, it is not necessary to go through the other speeds to reach the high or the low, as is the case with the progressive. Where there are only three speeds forward, and one in reversing, this is not so material, but as the better class cars have four speeds forward, it means that in order to reach _high_ the gear in a progressive system must go through two intermediate speeds. The shaft B, Fig. 47, which connects with the engine through a clutch, has its end journaled in a driven shaft A, and a gear C is fixed to the shaft B, and provided with a recessed side. This has internal teeth to receive the teeth of a sliding gear D. Another, smaller, sliding gear E is also on the shaft. [Illustration: Fig. 47. Selective Transmission. Low Gear.] Below the shafts A B is a shaft F, which carries a gear G, about half the diameter of the gear C, with which it is constantly in engagement. This shaft, further, has a gear I, the same diameter as the gear D, with which it meshes, and the shaft also carries a gear K, smaller than gear J. Behind the gear K is an idler pinion L, in such position that it may be slid into contact with K, and the gear E, on shaft B, is also adapted to be meshed with the pinion L by sliding contact. All the gears G I J K are keyed to the shaft F, and only the gears D E and L are capable of being shifted. LOW GEAR.--Fig. 47 shows the gears E J in engagement, and the motion is, therefore, transmitted from the shaft B, through gears E J and gear G to C, thereby giving a slow speed to the driven shaft A. This is called _low_ gear. [Illustration: Fig. 48. Intermediate.] INTERMEDIATE GEAR.--To change into the intermediate, the gear D, engages with I, Fig. 48, so that both shafts B F run at the same speed, but in opposite directions, since these two gears are of the same diameter. The selective mechanism, as hereinafter explained, shows how this may be done so that the gear E, will also be thrown out of engagement with J at the same time. It will, of course, be understood that while the gears E J turn the shaft F in a direction opposite the shaft B, the shaft A is again reversed by the gears G C, so that both shafts A B, turn in the same direction, but the shaft A, now turns at just half the speed of shaft B, because the gear G is only half the diameter of C. [Illustration: Fig. 49. High.] HIGH GEAR.--The direct drive, Fig. 49, is arranged by connecting the two shafts A B together, and this is done by means of the teeth of the wheel D, engaging with the internal teeth of the gear C, so that shaft A turns with the engine. REVERSE GEAR.--The reversing engagement is brought about by putting the gears K L E into mesh with each other, as in Fig. 50, thus making the transmission from shaft B, through gears E L and K, shaft F, and back to A, through gears G C. [Illustration: Fig. 50. Reverse.]