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Neeb
·I'm pretty confused about Longines serial numbers in this period.
Here's what I think I know (please correct if appropriate):
- Before 1969, serial numbers are on the movement, never on the outside of the caseback. They follow a strict numerical sequence initiated in 1867, and by 1969 they had reached 15,000,000.
- Sometime around 1969 or 1970(?), a new sequence for movement serial numbers was initiated, starting with 50,000,000 or thereabouts.
- However, starting in 1969, serial numbers start to appear on the outside of casebacks. These actually appear to follow the original numerical sequence, in that (for example) watches made in 1970 have caseback serial numbers in the 15,000,000s. This might not be immediately obvious looking at a caseback, as the first two digits are sometimes physically separated from the final six. But if you request an extract from the archives, the watch is identified by this serial number, not the movement serial number beginning with 50 (even if you have provided both), and it is written as an eight digit number.
- These caseback serial numbers, ostensibly following the original numerical sequence, continue well into the 1970s, running concurrently with the 50,xxx,xxx serial numbers on the movements. For example, I have an Admiral case from the 1970s with a caseback number in the 17,000,000s.
- There is a transitional period in 1969, after caseback serial numbers had been introduced, but before the 50,xxx,xxx movement serial numbers had started to appear on the movements fitted in these cases. Watches in this period appear to have serial numbers following the original sequence on both the caseback and the movement, although these don't match. E.g., the caseback will have a number in the 15,000,000s, but the movement may have a number in the high 14,000,000s (perhaps indicating that it was manufactured one or two years earlier than the case itself).
Here's what strikes me as the best way to explain this, based on what I have read elsewhere and my own observations (again, please correct me if I'm missing something!)
In 1969, when the movement serial number sequence reached 15,000,000, this same serial number sequence continued, but now as a case serial number rather than a movement serial number. At the same time, a new number sequence for movements was introduced, starting with 50,000,000. But in a transitional period in 1969, movements manufacured before this change were generally fitted to cases manufactured after the change (hence watches made at this time have caseback serial numbers in the 15,000,000s and movement serial numbers in the high 14,000,000s, while ones made in mid-1970 have caseback serial numbers in the 15,000,000s and movement serial numbers in the 50,000,000s).
If you currently request an extract from the archives and provide both caseback and movement serial numbers, the certificate only mentions the numbers in the original sequence, whether those appear on the movement, the caseback, or both. Movement serial numbers in the 50,000,000 series seem to be ignored (so perhaps Longines don't regard these as serial numbers as such).
It seems to me that Longines decided it was more practical to have the serial number for a watch on the outside of the caseback rather than on the movement, but in making that change also felt the need to introduce a completely new, parallel number sequence for the movements. But the caseback numbers in the 1970s do actually continue the time-honoured sequence started in 1867.
Does this all make sense? I must admit that as a relative novice I'm never sure when thinking about this stuff whether I'm just repeating/rediscovering things that a lot of people already know, or whether it's an area that no one actually knows much about (and possibly no one cares about, ha ha!).
Here's what I think I know (please correct if appropriate):
- Before 1969, serial numbers are on the movement, never on the outside of the caseback. They follow a strict numerical sequence initiated in 1867, and by 1969 they had reached 15,000,000.
- Sometime around 1969 or 1970(?), a new sequence for movement serial numbers was initiated, starting with 50,000,000 or thereabouts.
- However, starting in 1969, serial numbers start to appear on the outside of casebacks. These actually appear to follow the original numerical sequence, in that (for example) watches made in 1970 have caseback serial numbers in the 15,000,000s. This might not be immediately obvious looking at a caseback, as the first two digits are sometimes physically separated from the final six. But if you request an extract from the archives, the watch is identified by this serial number, not the movement serial number beginning with 50 (even if you have provided both), and it is written as an eight digit number.
- These caseback serial numbers, ostensibly following the original numerical sequence, continue well into the 1970s, running concurrently with the 50,xxx,xxx serial numbers on the movements. For example, I have an Admiral case from the 1970s with a caseback number in the 17,000,000s.
- There is a transitional period in 1969, after caseback serial numbers had been introduced, but before the 50,xxx,xxx movement serial numbers had started to appear on the movements fitted in these cases. Watches in this period appear to have serial numbers following the original sequence on both the caseback and the movement, although these don't match. E.g., the caseback will have a number in the 15,000,000s, but the movement may have a number in the high 14,000,000s (perhaps indicating that it was manufactured one or two years earlier than the case itself).
Here's what strikes me as the best way to explain this, based on what I have read elsewhere and my own observations (again, please correct me if I'm missing something!)
In 1969, when the movement serial number sequence reached 15,000,000, this same serial number sequence continued, but now as a case serial number rather than a movement serial number. At the same time, a new number sequence for movements was introduced, starting with 50,000,000. But in a transitional period in 1969, movements manufacured before this change were generally fitted to cases manufactured after the change (hence watches made at this time have caseback serial numbers in the 15,000,000s and movement serial numbers in the high 14,000,000s, while ones made in mid-1970 have caseback serial numbers in the 15,000,000s and movement serial numbers in the 50,000,000s).
If you currently request an extract from the archives and provide both caseback and movement serial numbers, the certificate only mentions the numbers in the original sequence, whether those appear on the movement, the caseback, or both. Movement serial numbers in the 50,000,000 series seem to be ignored (so perhaps Longines don't regard these as serial numbers as such).
It seems to me that Longines decided it was more practical to have the serial number for a watch on the outside of the caseback rather than on the movement, but in making that change also felt the need to introduce a completely new, parallel number sequence for the movements. But the caseback numbers in the 1970s do actually continue the time-honoured sequence started in 1867.
Does this all make sense? I must admit that as a relative novice I'm never sure when thinking about this stuff whether I'm just repeating/rediscovering things that a lot of people already know, or whether it's an area that no one actually knows much about (and possibly no one cares about, ha ha!).
