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Wednesday, May 31 • 3:30pm - 4:00pm
043. (Objects) Exploring methods for determining the age of clock mainsprings

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Many mechanical clocks utilize mainsprings made of steel as their power source. Through normal use and ageing these mainsprings may break or become weak which leads to their replacement. In essence, mainsprings have a finite life and are generally treated by clockmakers as a consumable part of the clock. As a result, historical data is lost when old mainsprings are discarded. Today, an original mainspring in an 18th century clock is rare. A survey of nearly seventy horologists demonstrated that 90% of what are perceived to be weak mainsprings are replaced during repairs or restoration projects. The survey also showed that maintaining a clock in working condition is amongst the most important goals for horologists. This goal stands in opposition to widely accepted conservation practice—maintaining historical integrity with minimal intervention—a functioning clock is destroying itself through use and normal wear. For the conservator, this raises the question of whether a mainspring can legitimately be treated as a consumable, or should be preserved as part of the historic integrity of the clock above all other factors. A literature search indicated that published articles relating to conservation of clock movements are few, and those relating to mainsprings—particularly determination of the age of a mainspring—even fewer to non-existent. The goal of this research is to provide a guide for determining the age of a mainspring so that a more informed decision can be made about its retention or replacement. An historical study of the mainspring manufacturing process led to the definition of four broad eras that may be differentiated by visual and analytical techniques. An initial study of twenty mainsprings was conducted using visual inspection, microscopy, and x-ray fluorescence techniques. The test results demonstrated that the general date of a mainspring can be determined. A case study has been used to demonstrate issues in an actual clock and resulted in the determination that its mainspring was most likely original to the clock. The work carried out points the way for further study, testing, and analysis.

avatar for Mostyn Gale

Mostyn Gale

Owner/Conservator, Saving Time
After leaving the US Air Force in 1976 Mostyn continued his electronics education, graduating from UC Santa Barbara, CA with a BSEE degree in 1981. He practiced his engineering at Raytheon in Santa Barbara, developing infrared focal planes, but quickly learned that his best skills... Read More →

Wednesday May 31, 2017 3:30pm - 4:00pm
Riverside West Exhibit Hall Exhibit Level, East Tower

Attendees (18)