Thomas A. Watson played a pivotal role in the development of early telephone technology alongside Alexander Graham Bell. Watson's innovative contributions include the creation of the first telephone bell (ringer) and a hand-activated voltage generator known as the Buzzer. These inventions helped improve the efficiency of
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The Evolution of Annunciator Signaling for TelephonesSome of the text and images below are derived from Thomas A. Watson’s book, “ The Birth and Babyhood of the Telephone", October 17, 1913 . From day one, the problem of announcing an incoming call was a challenge. What we call a telephone “bell, buzzer, or ringer” (an annunciator) would not be invented until a few years after the telephone’s invention in 1876. So how did a caller know of an incoming call? One method according to [Gertner, page 47] was for the caller to yell, "Ahoy!" into their mouthpiece. At first, phones were always "off hook" since there was no hook. Could a pencil or hammer help somehow? Let’s see. Charles Williams, a business associate of Alexander G. Bell and Thomas A. Watson, is credited by Watson for using the butt end of a lead pencil to vigorously “thump” on the diaphragm of his (calling) telephone’s mouthpiece. If there was someone close to the called-telephone, the thumping sound would announce the call. This case was for a one-to-one call before the switchboard was invented. However, pounding a pencil against the diaphragm could seriously damage the vitals of the calling-telephone and therefore wasn’t practical. Also, according to Watson, “We might have to supply a pencil with every telephone and that would be expensive.” Hammer Signaling Watson saw an opportunity to make improvements. He said, “I rigged a little hammer inside the box with a button on the outside. When the button was thumped (by the caller) the hammer would hit the side of the diaphragm where it could not be damaged. The usual electrical transformation took place, and a much more modest but still unmistakable thump sound would be emitted from the telephone at the other end.” Figure 1 shows a box telephone with the Watson Hammer (or "Thumper"). Notice the push button on the lower left. A caller would operate it repeatedly and the hammer would hit the diaphragm to subsequently make a sound on the called-telephone’s ear/mouth piece. Crude, but it worked to an extent. Note that for this early telephone the mouth and ear pieces were the same transducer.Fig 1, Box Telephone with Watson Hammer Signaling, showing a combined ear and mouth pieceFigure 2, Watson’s “Buzzer” voltage generatorFig 3, A 5-bar magneto from the Swedish American Telephone CompanyFig 4, Six ganged magnetos driven by an external motor (1882 Western Electric catalog)So, solutions for the calling-end voltage generator were making good strides. What about the sound annunciator at the called-station? Watson gave this consideration too.Fig 5, Watson-like ringer, Smithsonian Institution, circa 1885Sort: