Model 19 was described by Roy Ehrhardt in his Identification and Price Guide to American Pocket Watches [*15] as a 6-size hunting movement in gilt or nickel, pendant or lever set, with a Breguet hairspring, sharing the EA 821 configuration with Model 18 movements. One might initially conclude that the Breguet hairspring is the only difference between the movements; but that is not actually the case.  As a study of Model 17 teaches us, when Seth Thomas designed a 6-size movement to utilize the Breguet hairspring a subtle modification was made to the regulator and the balance bridge to maximize the effectiveness of the Breguet hairspring for that movement. That subtle design modification was also found on Model 19 regulators and balance bridges.

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