Sibyl Rock and Innovation

In the 1940s and 1950s, as instrumentation improved and demand skyrocketed, mass spectrometers were finally being commercialized. And the number of people who needed a working understanding of mass spectrometry—how the instruments were built, how they functioned, what they did—grew as well. Two distinct groups emerged: those who built and manufactured the instruments and those who used them. But the gulf of knowledge between these groups made intermediaries a necessity. The intermediaries needed to translate technical information into easily understandable guidelines for use of the instruments and interpretation of the data, communicate the needs of the users to the technical designers, and communicate the needs of sales representatives in the field to the engineers. One such person was Sibyl Rock, a vital part of Consolidated Engineering Corporation’s (CEC) mass-spectrometry operational team. Rock was a mathematician by training and held the position of geophysical computer at both the Rieber Laboratories and United Geophysical Corporation. She joined CEC the year it was created (as the engineering and manufacturing subsidiary of United Geophysical) and worked in the research department before being transferred to sales in 1947. By 1953 she was ElectroData Corporation’s first female sales engineer.

Meyerson notes

Seymour Meyerson's notes from a CEC meeting detailing Rock's contributions. CHF Collections. Click here for full size

Rock’s work was vital during a time when mass spectrometers as well as their uses were being expanded and therefore rapidly changing. Seymour Meyerson, who worked closely with Rock while at CEC, noted:

There was a lot of instrument development that was still needed at that point. And as I think you may be aware, as I’ve stated elsewhere, when that instrument was sold to Indiana Standard in 1943, the sales contract included a provision that any instrumental developments or improvements that might occur there within the company’s laboratories would be made available without any cost, without royalty, to Consolidated. So there were a good many instrumental developments that took place there in our laboratory, that took place in users’ laboratories in lots of other places that were fed back to Consolidated, and many of them were incorporated into the design of subsequent instruments. (23)


Clearly, there was a community of mass-spectrometer users, and this community was developing instruments for its own purposes on a lab-by-lab basis. Ensuring that communication between various companies’ labs and instrument developers like CEC went smoothly was key to the success of early mass spectrometrists. 

Rock letter to Harold Wiley regarding computing, 1943. CHF Collections. Click here for full size

This feedback loop that used customer evaluations to improve instrumentation required Rock’s knowledge of both the technical inner workings of the instrument, including the computations it was supposed to complete, and the needs of the growing list of customers CEC supplied with instrumentation. Rock collaborated with another CEC employee, Harold Wiley, manager of chemical instruments, to gauge the operational status and the need for improvement of new and old instrumentation and generally to understand what the latest methods, problems, and critiques were among users. In a 1943 letter to Wiley, Rock detailed the various methods she had learned about in the community for solving simultaneous equations. During this time a vibrant dialogue was going on within the early users group of mass spectrometers. Rock was inquisitive about the status of the users and their work with the new instruments, and noted at the end of her letter to Wiley, “I’d like to hear about any bright ideas they strike” This dialogue was key to ensuring that the instruments—and CEC—were successful, but it also helped the community of budding mass spectrometrists develop.

The title page of Rock's CEC Computing Manual. CHF Collections. Click here for full size.

By the mid-1940s Rock had made several outstanding contributions to the field; one of her greatest achievements while at CEC was her 1946 manual, Computing Manual: Analysis of Gas and Liquid Mixtures by Means of the Mass Spectrometer. Rock’s work on such manuals contributed to the creation of standards for instruments and methods that were developing at a truly rapid pace. In the same year, along with Clifford Berry, she developed an analog computer that could handle the many simultaneous linear equations necessary to complete an analysis of the data that a mass spectrometer generated. The communication between CEC and its customers was not one-sided. In a 1947 letter to Wiley, Rock wrote, “I have read several of your field reports to the office, and it seems to me that it is time for the office to report to the field.” Rock’s ability to understand, simplify, and communicate complex calculations and methods meant that she was not only an appropriate person to provide a link between users and developers of the instruments, but she was equally well-suited to bringing together the hard work, research, and recommendations of both groups into something useful for all.

As a woman in a male-dominated industry, Rock flourished while working closely with Berry and Harold Washburn, both electrical engineers by training. Along with her colleagues, she was active in publishing and coauthored several publications. In another 1947 letter to Wiley she explained that she and a colleague “have decided to write a paper for the ACS meeting [. . .] on qualitative analysis by means of the MS [mass spectrometer], which will emphasize the wealth of information obtainable with no more than a casual glance at the record” Her publications included a paper on mass-spectrometer analysis of some of the first smog samples from the town of Pasadena, California, a topic that would become important to mass spectrometry later on. Her ability to serve as a go-between for various technically minded groups and her ability to communicate complicated data and technical information made CEC instruments easier to use and understand, and as a consequence more desired by the mass-spec community. Rock’s work with early digital computers accelerated adoption of such instruments as the Datatron—CEC’s early digital computer—and her work to create brochures and command lists and attack coding problems made the instrument comprehensible to its new users. After her transfer to sales Rock frequently traveled to industrial and academic labs, selling instruments and educating users on the new wave of computing.

But she also went beyond her job at CEC to help pave the way for other women to enter into careers in engineering and the sciences; she gave speeches for school and college groups, urging girls to enter math and scientific fields. A pioneer, Rock worked behind the scenes to ensure mass spectrometry—and computer—adoption and success in the early days of mass spectrometry.

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