W. Lister & Sons

W. Lister & Sons, Ltd, 32 & 34 Northumberland St., Newcastle-on-Tyne, London hallmarks of 1921.Exceptionally fine and very rare 18K gold keyless pocket watch with one-minute tourbillon regulator. Three-body, by Frederick Thoms, "bassine 5 pommes", gold glazed cuvette, polished. White enamel, Roman numerals, outer minute track, subsidiary sunk seconds. Notes Unusual tourbillon - it is based on Nicole, Nielsen ebauche as well as on their carriage. However, their carriages were equidistant with three-arms. The two-armed ones, like the one in this watch, they used very rarely. It is an excellent design that in the hands of skilled watchmaker will perform superbly. The change from three arms to two takes a little weight off the carriage, which should be as light as possible because going train transmission of a watch moves in jumping fashion in the rhyhm of the escapement. It stops and re-starts every fifth of a second. Furthermore, during unlocking it moves slightly backwards. The same happens to the carriage, it runs when unlocked by the escapement, then it stops, moves slightly backward and restarts again. And so, the heavier the carriage, the escapement is less effective - the unlocking requires more power. In heavy train the momentum exerted on the pallets differ considerably at the beginning of the impulse and at the end. Actually, no mtter what train, it is never constant, but the heavier the train, the larger this difference becomes.Because of that the good makers Read more…