Your Friday Reading: “Talking Rubber”

It’s Friday afternoon! Let’s look into the archives of physics and pretend we’re still working.

“Hi, you’ve reached Eran. Please leave a message, and I’ll get back to you.”

That’s my voice mail message on my cell phone that I recorded in high school and can’t figure out how to change. Although I’m still a loyal proponent of phone calls themselves, I have to admit, I probably don’t check my voice mail as much as I should.

And it’s not just me. As young people shy away from leaving voice messages and an email or text message can instantly reach business colleagues, we may have moved beyond the simple answering machine.

But for every quotidian and arcane technological marvel, there was a time when it required a gentle, in-depth explanation. Think of the current press for self-driving cars or smart watches. Every new technology has to answer: what it is, how we are supposed to use it, and why we would ever want to use it in the first place.

In November 1954, this full-page ad ran in several publications, including Scientific American, Popular Mechanics, and Chemical Engineering News.

Bell Labs presents “talking rubber” answering machines.
Image Credit: Popular Mechanics, 1954

In 1925, AT&T opened Bell Labs in Murray Hill, New Jersey, a corporate research lab that came to be known for its emphasis on basic research and the latitude it gave scientists and engineers to pursue their research interests. Work conducted at Bell Labs led to seven Nobel Prizes in Physics and one in Chemistry between 1937 and 2009.

Bell Labs still exists—sort of. AT&T sold the labs to a French communications company that closed the labs’ physics research department in favor of more applied communications and networking research. In 2016, Nokia bought that company and what’s left of Bell Labs—which still employs research scientists but now focuses on applied research—along with it.

Megan Prelinger, co-founder of the Prelinger Library in San Francisco and author of Another Science Fiction: Advertising the Space Race 1957-1962, put it this way: “Bell Labs had a very intense culture of scientific experiment and innovation…The philosophy was that an unfettered environment for pure research that might go in any direction would probably birth fruit that would have commercial applications.”

“There’s not really an analogy to anything like it today,” Prelinger said. The closest instance of a commercial entity taking an interest in basic experiment, Prelinger thought, might be Google’s (and other tech companies) 20% policy, the somewhat unequally-enforced idea that employees at some big tech companies can take a limited portion of their work time to pursue self-driven pet projects.

1954 was the year the American public was introduced to the transistor, the small (in the ‘50s, a few inches long; now, as small as 1 nm) device to control and amplify electric current that would go on to power small transistor radios and eventually be included in everything from computers and smartphones to televisions and air-conditioners.

Bell Labs is famous for the transistor and other inventions, but there is a little-known history of Bell Labs and the answering machine as well.

Inventors at Bell Labs also created an early form of the answering machine in the ‘30s, decades before answering machines would go to market in the U.S. AT&T suppressed the technology because, as Mark Clark wrote in his 1993 Technology and Culture article, “management fears that the availability of a recording device would make customers less willing to use the service…if conversations became matters of record in the same way as letters or other contracts, managers felt that customers would abandon the telephone for critical negotiations and return to the mails, where a slip of the tongue would not prove fatal.”

Dave Morton, who wrote Off the Record: The Technology and Culture of Sound Recording in America, took a look at this ad and said, “It’s kind of funny, because Bell Telephone Labs had given this [answering machine technology] up 20 years before this,” when they decided not to pursue Clarance Hickman’s answering machine service that was in internal use at Bell Labs.

Look at the way ad explains the technology behind its device: “The new machine features ‘talking rubber,’ a Laboratories-developed recording medium of rubber-like plastic and iron oxide with can be used over and over again millions of times.”

There are several things going on here: first, what is the “talking rubber” technology? After talking to several historians of science and technology, I’m pretty sure it’s not a term that ever caught on. But it turns out that’s because this actual technology never caught on; although on first glance, this ad seems to describe magnetic tape—the technology behind cassette and VHS tapes—“talking rubber” describes actual rubber, not tape! In 1952, The Bell System Technical Journal chronicled “a magnetic recording medium composed of rubber impregnated with magnetic oxide and lubricant,” that was “particularly suited to applications requiring the continuous repetition of short transcribed messages.”

While common magnetic tape uses very thin plastic coated iron oxide, “talking rubber” uses rubber impregnated with iron oxide. Iron oxide (a from of rust) is ferromagnetic, which means in the presence of a magnetic field, the electrons in the iron oxide magnetically line up and stay that way even after the magnetic field is turned off. This allows cassette tapes to create a “track” of magnetically aligned iron oxide when the electromagnet in a cassette recorder creates a magnetic field.

But with magnetic rubber, the iron oxide is actually mixed into the rubber material; the whole band becomes ferromagnetic, instead of just the coating. According to that Bell System Journal article, this “talking rubber” could be around 1/16 or 1/8 of an inch think, whereas magnetic tape was (even in the ’50s) already much thinner at 1/1000 of an inch thick.

Even though AT&T decided not to pursue Clarence Hickman’s version of magnetic tape from the ‘30s, by the ‘50s the company was looking for a way to record very short messages that could be played over and over again and then re-recorded at various intervals. At the time, local telephone companies provided a service where you could call and someone would tell you the current time or the current weather report (eventually they also had some recounting current stock reports). The “talking rubber” invention allowed AT&T to record these very short messages and play automated time, weather, or stock reports over the phone. As you can see from the ad, AT&T started selling this technology for use outside of the company in 1954.

Except the technology never caught on; magnetic tape, not rubber, reigned. Part of this may have been due to the short nature of rubber recordings because the rubber was so much thicker than tape. As Morton wrote in an email, “you could easily record hours of phone messages on a reel of tape no bigger than [a] 30-second band,” of magnetic rubber.

But in the end, Morton sees the demise of the magnetic rubber as due to a “range of technical and non-technical reasons.” The magnetic rubber did come with more background noise at low frequencies than magnetic tape, and there many have been cost concerns, but there was also a patent issue.

“AT&T had hastily developed this rubber medium after WWII,” wrote Morton in an email. Then, he wrote, “along comes German-style [magnetic recording] tape after 1945, which was the end result of decades of development and commercial application in radio and motion pictures in Europe. Companies got essentially patent-free access to German tape recording technology after 1945 because it was considered captured enemy intelligence.”

Matt Wisnioski, Associate Professor for the Department of Science and Technology in Society at Virginia Tech, noticed that the tag line included with the Bell Labs logo on this ad—which was not included in all of their advertisements—“makes it seem like this is a recruiting tagline…it seems to convey that element.” Around this time, AT&T ran many recruiting ads featuring Bell Labs as a place where you could parlay your physics or other technical degree into a normal ‘50s suburban job.

To add to this idea, Wisnioski emphasized that in 1954, running an ad in Scientific American or Popular Mechanics meant addressing an audience of scientists and engineers.

“Now [they’re] more like a general interest magazines,” Wisnioski said. “But [these publications] were much more prominent at the time as a way to bring together a broad scientific universe…people who employ scientists, scientists themselves, engineers…”

And after WWII, as I mentioned in my last Friday Reading, there was a huge increase in the number of students and professional in science and engineering.

Just look at the ad at face value—especially the last line, “It [the answering machine] is another example of how Bell Laboratories research works to help your local Bell Telephone Company serve you in new ways” and the tag line “Improving telephone service for American provides careers for men in scientific and technical fields.” These lines, Wisnioski said, lead him to see the ad as “selling the laboratory and what’s happening there perhaps even more so than this specific product.” Wisnioski added that this means the advertisement works to defend “the idea of corporate-sponsored basic research.”

That could be because, at this time, the very concept of an answering machine might have seemed impossible. You have to remember, in 1954 the only way to record sound was to press a phonograph or record sound on film for a movie. When I talked to historian of science David Kasier, he emphasized that in this particular period, what might have seemed amazing was not recording itself, but re-recording.

“At this point [1954] you could press a record…that technology had existed for half a century, but you had to basically just record it once (grind grooves into the record) and hope it doesn’t break. So the novelty of this more recent period could be that you could record a new layer on top of an existing recording,” Kaiser said. The sound filmstrips that were included on the sides of American movie reels in the 1950s were also permanent.

Look at the way the device is presented in this ad. “Before you leave,” the ad goes, “you twist a knob, dictate a message into your telephone, the switch the machine to ‘Automatic Answer.’ When somebody calls, the machine starts up and the caller hears your voice telling who you are, asking his name and telephone number, repeating what you have said.”

Reading this, it’s interesting to think this ad is presenting a setup that would allow—and possibly demand—you to record a different outgoing message every time you left the office. As I researched this ad, it made more sense; if this technology came from AT&T using “talking rubber” to record the time or the weather, that’s a very short message that that is always being re-recorded.

To me, what’s interesting is the pause in time this advertisement suggests, and the window into how the advertisers, and Bell Labs, saw customers using the telephone. It suggests a phone manner that is much more intimately related with your business/personal schedule, as if you would be leaving messages like “I’m in a meeting with so-and-so until three, please leave a message.”

So when you see advertisements or articles about self-driving cars, wearable technology, or other high-tech inventions, remember that, even if that particular technology catches on, the way we end up using it might differ from what the inventors or advertisers had in mind.

—Eran Moore Rea

For further information:

A 2010 Gizmodo excerpt from Thomas Lin’s book, “The Master Switch: The Rise and Fall of Information Empires. This excerpt cites Mark Clark’s 1993 article

Dave Morton’s overview of the history of the answering machine.

David Kaiser’s “The Postwar Suburbanization of American Physics.”

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