Since its invention 140 years ago, the telephone has gone through an amazing evolution. All the way from switchboards and operators, to iPhones and FaceTime, it’s incredible how far we’ve come. Although touch screens seem to be the trend these days, the style that stands out as the most popular form of communication for the majority of the 20th century is the rotary phone. (If you don’t know what a rotary phone is, please refer to this video, and then proceed on with the article)
Despite the novelty of the circular dialing board, the rotary phone was actually more revolutionary than you would expect. Prior to its invention you had to go though telephone operators to connect you to who you wanted to speak to. The rotary phone allowed people to completely bypass that cumbersome task, and simply dial the number of the recipient directly. This set the standard for the future of telecommunications, and made phone operators nearly obsolete by 1919.
The rotary phone uses technology known as pulse dialing. When one of the 10 numbers on the rotary dial are rotated all the way to the stop position, and then released, the wheel returns to it’s original position with the help of a spring. As it spins, the dial interrupts the direct electrical current of the telephone line a set number of times for each digit. This creates the electrical pulses, which the telephone recognizes as code for each digit, one pulse for each number value, and ten for the 0 digit.
The rotary phone remained the dominant style of phone throughout most of the 20th century, until the 1970’s when push button technology became a more effective means of dialing. Today rotary phones are nearly extinct, but the novelty aspect of them still remains. There is something romantic about seeing those old phones, and some of them have remarkable craftsmanship that can still be appreciated to this day. So next time you watch an old movie and see a rotary phone, just think about how far we have come in advancing communications since then.