Efficiency and authority in the ‘Open versus closed’ transformer controversy

Summary

In the 1880s, there had existed a series of controversies between the proponents of open and closed transformers. James Swinburne reopened it in 1889 when he designed a new type of open ‘Hedgehog’ transformer, and argued that it had the highest all-day efficiency. Three years later, John Ambrose Fleming showed that the Hedgehog was not the best but rather close to the worst. The bitter controversy between Swinburne and Fleming ended quickly, as Fleming made the unstable AC power measurement stable by creating agreement concerning the calibration of AC instruments with the help of Kelvin's authority. Instruments, measurement, and calibration were intimately bound up with hegemonic issues in late-Victorian electrical engineering.