Reference:2574: Difference between revisions

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Two details set the 2574 apart. First, some examples carry the reference engraving on the outside of the caseback rather than inside, which is unusual enough to help with authentication. Second, the watch uses a smaller 9¾-ligne 17-jewel Aegler movement, and that caliber appears on the 2574 in two distinct dial layouts.

The two layouts ~~are worth naming carefully because period catalog material and modern dealer descriptions tend to use the terms loosely~~. A center-seconds dial (also called sweep seconds, centre-seconds, or seconde au centre) carries a single long seconds hand pivoting from the center of the dial, alongside the hour and minute hands. A sub-seconds dial (also called small seconds, petite seconde, or sub-dial seconds) carries a separate small register, usually at six o'clock, with its own short seconds hand running on its own pinion. The two layouts require different gear-train configurations downstream of the fourth wheel and are not interchangeable on a finished movement.

The two layouts of 2574 exist. A center-seconds dial (also called sweep seconds, centre-seconds, or seconde au centre) carries a single long seconds hand pivoting from the center of the dial, alongside the hour and minute hands. A sub-seconds dial (also called small seconds, petite seconde, or sub-dial seconds) carries a separate small register, usually at six o'clock, with its own short seconds hand running on its own pinion. The two layouts require different gear-train configurations downstream of the fourth wheel and are not interchangeable on a finished movement.

On the 2574 both configurations appear in the surfaced corpus. The 1943 Royalite Observatory shown above is a center-seconds layout; the 1936 Imperial Chronometer is a sub-seconds layout. Whether early production ran sub-seconds and later production switched to center-seconds, or whether both were offered concurrently, the surfaced sample is too thin to settle. What the dial layout does establish is a quick authentication check: a 9¾-ligne caliber paired with the wrong dial layout for that movement variant points either to a service replacement or to a misidentified reference.

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 Two details set the 2574 apart. First, some examples carry the reference engraving on the outside of the caseback rather than inside, which is unusual enough to help with authentication. Second, the watch uses a smaller 9¾-ligne 17-jewel Aegler movement, and that caliber appears on the 2574 in two distinct dial layouts.
-The two layouts are worth naming carefully because period catalog material and modern dealer descriptions tend to use the terms loosely. A center-seconds dial (also called sweep seconds, centre-seconds, or seconde au centre) carries a single long seconds hand pivoting from the center of the dial, alongside the hour and minute hands. A sub-seconds dial (also called small seconds, petite seconde, or sub-dial seconds) carries a separate small register, usually at six o'clock, with its own short seconds hand running on its own pinion. The two layouts require different gear-train configurations downstream of the fourth wheel and are not interchangeable on a finished movement.
+The two layouts of 2574 exist. A center-seconds dial (also called sweep seconds, centre-seconds, or seconde au centre) carries a single long seconds hand pivoting from the center of the dial, alongside the hour and minute hands. A sub-seconds dial (also called small seconds, petite seconde, or sub-dial seconds) carries a separate small register, usually at six o'clock, with its own short seconds hand running on its own pinion. The two layouts require different gear-train configurations downstream of the fourth wheel and are not interchangeable on a finished movement.
 On the 2574 both configurations appear in the surfaced corpus. The 1943 Royalite Observatory shown above is a center-seconds layout; the 1936 Imperial Chronometer is a sub-seconds layout. Whether early production ran sub-seconds and later production switched to center-seconds, or whether both were offered concurrently, the surfaced sample is too thin to settle. What the dial layout does establish is a quick authentication check: a 9¾-ligne caliber paired with the wrong dial layout for that movement variant points either to a service replacement or to a misidentified reference.