# Longines Cal. 19.73N P/W



## Seismic one (Jun 21, 2008)

I own a Longines P/W calibre 19.73 N with the normal split balance wheel blue steel hairspring but an associate has a watch with the following differances can anyone shed some light on this anomaly as to date it has baffled us.

Model 19.73, a chronograph cased in an 18K case. It was produced in 1903. S/N 1368584

The balance wheel seems to be mono-metallic and has no splits.. The hairspring is a white color, not the blue as expected.

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Would you know what kind of white alloy, self-compensating hairsprings were used in conjunction with an uncut, mono-metallic balance that would have been available back in 1903

Were non-magnetic hairsprings available back then, such as Palladium hairsprings.

This is my 1899 watch


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