Waterman pens and dynamometers

Waterman collectors have long been aware of the Signagraph, a form of pantograph that allowed its operator to sign multiple documents (payroll checks, typically) at once. The Signagraph was not the only application in which Waterman pens were utilized for mechanical output, however, as we can read in the ad below.

Popular Mechanics, Aug 1911, p. 107

Railroad dynamometers were typically built into a special-purpose car, which is why we have not seen any turn up at a pen show, or on eBay for that matter. Waterman advertisements continued to make period mention of their pens' use in dynamometers for some years. The ad below ran in Scientific American, vol. 122 (May 1, 1920), p. 500, as well as Collier's, vol. 65 (May 22, 1920), p. 47 and others.