manufacturers, Western Electric for the Bell System, and the Automatic Electric Company. The Western Electric dial had spur gears to power the governor, so the governor and dial shafts were parallel. The Automatic Electric governor shaft was parallel to the plane of the dial. Its shaft had worm gearing in which, very atypically, the gear drove the worm. The worm, highly polished, had extreme pitch, its teeth at about 45° to its axis. This was the same as the gearing for the speed-limiting fan in traditional music boxes. The Western Electric governor was a cup surrounding spring-loaded pivoted weights with friction pads. The Automatic Electric governor had weights on the middles of curved springs made from strip stock. When it speeded up after the dial was released, the weights moved outward, pulling the ends of their springs together. Springs were fixed to a collar on the shaft at one end, and to the hub of a sliding brake disc at the other end. At speed, the brake disc contacted a friction pad. This governor was similar to that in spring-driven windup phonograph turntables of the early 20th century. Both types had wrap-spring clutches for driving their governors. When winding the dial-return spring, these clutches disconnected to let the dial turn quickly. When the dial was released, the clutch spring wrapped tightly to drive the governor. While winding the dial, a spring-centered pawl in the Western Electric dial wiggled off-center when driven by the cam on the dial shaft. Teeth on that cam were spaced apart by the same angle as dial hole spacing. During winding, the pawl moved off-center away from the normally-closed pulsing contacts. When the dial was released, the cam teeth moved the pawl the other way to open and release the dial contacts. In the Automatic Electric dial, the pulsing cam and governor were driven by a wrap-spring clutch as the dial returned. When winding, that clutch disconnected both cam and governor. Recoil spring Early dials worked by direct or forward action. The pulses were generated as the dial turned toward the finger stop position. When the user's hand motion was erratic, it produced the wrong numbers. In the late 19th century, the dial was refined to operate automatically by a recoil spring. The user selected the digit to be dialed, rotated the dial to the finger stop, then released it. The spring caused the dial to