subscriber wanted to call. Most inventions involved costly, intricate mechanisms and required the user to perform complex manipulations. The first commercial installation of a telephone dial accompanied the first commercial installation of a 99-line automatic telephone exchange in La Porte, Indiana, in 1892, which was based on the 1891 Strowger designs. The original dials required complex operational sequences. A workable, albeit error-prone, system was invented by the Automatic Electric Company using three push-buttons on the telephone. These buttons represented the hundreds, tens, and single units of a telephone number. When calling the subscriber number 163, for example, the user had to push the hundreds button once, followed by six presses of the tens button, and three presses of the units button. In 1896, this system was supplanted by an automatic contact-making machine, or calling device. Further development continued during the 1890s and the early 1900s in conjunction with improvements in switching technology. Almon Brown Strowger was the first to file a patent for a rotary dial on December 21, 1891, which was awarded on November 29, 1892, as . The early rotary dials used lugs on a finger plate instead of holes, and did not produce a linear sequence of pulses, but interrupted two independent circuits for control of relays in the exchange switch. The pulse train was generated without the control of spring action or a governor on the forward movement of the wheel, which proved to be difficult to operate correctly. Despite their lack of modern features, rotary dials occasionally find special uses, particularly in industrial equipment. For instance, the anti-drug Fairlawn Coalition of the Anacostia section of Washington, D.C., persuaded the phone company to reinstall rotary-dial pay phones in the 1980s to discourage loitering by drug purchasers, since they lacked a telephone keypad to leave messages on dealers' pagers. They are also retained for authenticity in historic properties such as the U.S. Route 66 Blue Swallow Motel, which date back to the era of named exchanges and pulse dialing. Function To dial a number, the user inserts a finger into the corresponding finger hole and rotates the dial clockwise until it reaches the finger stop. The user then pulls out the finger, and a spring in the dial returns the wheel to the resting position. During the period of return, the dial operates electrical contacts that break the line current to the exchange a different number of