On 90% of My early Bulova Cases' (1920 - 1930) the first digit of the seriel number coincides with the Year of manufacture.
eg:
6xxxxxxxx - 1926
7xxxxxxxx - 1927
8xxxxxxxx - 1928
9xxxxxxxx - 1929
Anyone else seeing this?
In reply to Doubtful there will ever be by FifthAvenueRes…
I think it is a very provable theory Mark, I just went through all of the watches that I added into the database and the 1st number of the serial is very consistent with the movement date code all the way up to 1946-47, after that I start seeing the serial numbers start with a letter around the same time casebacks get datecoded.
All of mine except only a couple are consistant with the movement datecode up to '46, and the couple that are not, are within 1 year above or below the movement stamp.
The casebacks that are datecoded also seem to have ascending alphabet letters starting with "A", but can very a couple of letters in a given year...maybe different manufacturing plant designations??
In reply to I think it is a very provable by OldTicker
Perhaps not prove, but demonstrate more than just a pattern exists. With a large enough accurate (filtered) data set one can do more than armwaving. Meet some basic assumptions for these data and the statictical test(s) one applies, and the results could be published in a peer-reviewed journal. ...it just may not be the results one expects, but would be very helpful regardless.
In reply to Perhaps not prove, but by William Smith
....whoops.....to much coffee this AM and I musta put my plastic pencil protector in my shirt pocket without realizing it. I don't know what backend admin has for it's database, but I sure would love to go fishing sometime if the need ever comes up. Besides old Bulova watches, I've got other strange habits, and crunching data sets is high on my list of "how to have a good time" :)
Ok I've checked a database I have been keeping for some 6 years that records serial numbers and date codes and find a great many that do not follow this theory. This does not disprove anything as these movements could have been swapped into a different case over the many many years.
Also if you goto the watch search page http://www.mybulova.com/search-bulova-watches and type in '7' into the Case Serial number input box you will see a variety of different years come up which does agree with my own database findings.
Then I suggest these Cases would contain swapped movements - the evidence clearly shows a strong pattern that the first digit of a Case seriel number is its manufacture Date.
IMO.
and, as with the Date coded Cases ( late 1940's+ ) it's not out of the question to see a Years difference between the Movement and Case manufacture Date.
2c
and this is leading me into a new search area - this site has taught me that the case on old Bulovas may not be what the watch movement is, date wise, even style wise. I've seen 2 examples of my vintage Bulova with a solid gold case. Just like mine. By serial no., my case would be mfg'd in 1942. The movement a 1943. (I now believe.) My watch was gifted at Xmas 1944, and is engraved as such on back of case. But back then, jewelry stores didn't just have give-away close-out sales on something that was "last years".
How nice that must have been. Find a style you like, face-wise, and then choose the case you think it looks best in. Because my watch as originally designed did not come in a solid gold case, it was gold filled.
I seem to recall that many goods, not just watches were sold that way. A purchaser could customize (for a price) almost anything.