Early 1920s Bulova watch dating

Submitted by mybulova_admin on September 1, 2014 - 9:16am

I'd like to officially put this forward to the myBulova.com community at large to scrutinize and see if it holds true. We've always had a problem dating the very early 1920s vintage Bulova wstches  and often used the first number in the case serial number to date the year of production.

Well I'd like to suggest that for pre 1924 watches (pre movement date code) we use the second number to date the year of production.

In studying a good number of pre 1924 models we have in the database I find the common component of the case serial number having a second digit beginning with either '0 1 2 3', thus corresponding to the years 1920,21,22,23.

Further we have examples of watches that have the first two digits of the case serial number '13.....' and the corresponding movement stamp of 'Bulova Watch Co.' rather than the pre 1923 movement stamp of 'Bulova W Co.'

I'm asking the community to put this to the test and examine all watches with a serial number beginning with a '1' and of course being pre 1924.

There are some exceptions to this but they are all sold gold cases and it looks like these had a different serial number pattern yet to identified. As always thoughts and comments welcome.... Just be gentle :-)

 

mybulova_admin
Posted September 1, 2014 - 9:41am

 

Also note that case serial numbers starting with '10....' have a globe stamp, whilst those starting with either '11..... 12..... 13......' have the shield.

bobbee
Posted September 1, 2014 - 10:32am

Lisa has five watches with "Lady Maxim" on the dial, and the earliest ad from May 1921 has the Hudson/Ladies Hudson Maxim as being the "introduction" of these new watch lines.

Not one of her LM's has a "1" as the second number, all have a "0".

There is also this Rubaiyat with a second number in the sn being a "4", Rubaiyats are known to be from earliest use 1916, the unengraved case style of this watch not seen post 1920. Has early Wadsworth case, no globe or shield. We have ads for early watches as using Wadsworth cases.

http://www.watchophilia.com/photogallery/bulovas-1917-1929/a1917-rubaiyat4/

 

I'll look further into it Stephen, but I can't be sure.

mybulova_admin
Posted September 1, 2014 - 10:41am

In reply to by bobbee

 

Just a thought but there may have been a gap between the production of a case and its eventual release to the market. For example, case manufactured in late 1920 and finally assembled with the movement, shipped and marketed and in the jewelers store ready for sale in early 1921. The adverts may not necessarily be indicative as to when the watch was actually manufacture. Just because an advert is from 1921/22 doesn't mean to me that the watch was manufactured in that year. I'm sure some watches produced in 1920 were still being marketed and sold in 1921/22.

As I said above the sold gold models had a different serial number system and I don't think we can necessarily being Wadsworth cases into the equation. I'm just referring to Bulova's American Standard cases starting with a '1' that have either a globe or shield stamp.

 

bobbee
Posted September 1, 2014 - 11:16am

We have examples in the db that start with other than a "1" that are not solid gold. With more than 90% of watches pre-1923 having case sn's with a second digit being "0", , and lots being either 1921, or pre-1920, I don't think it's panning out yet.

 More info required on this one.

mybulova_admin
Posted September 1, 2014 - 11:51am

In reply to by bobbee

 

I've always held the belief that Bulova went gang busters in manufacturing watches in 1919 and 1920, due to the post war uptake of men's wrist watches and ladies time pieces. I know that others were making them earlier than this but it seems to me that Bulova came into the wristwatch market at the right time as they were becoming popular with the ladies and men moving away from traditional pocket watches.

It's my thought that Bulova invested a lot of time and money in manufacturing a great number of wrist watch in 1919/20 to basically dominate the market place in 1921/22, which would explain their sudden rise to prosperity over the next few years of the early 1920s. This might also explain why we also see so many watches starting work '10......'

 

 

mybulova_admin
Posted September 1, 2014 - 11:42am

In reply to by bobbee

[quote=bobbee]

Rubaiyat with case sn starting with "27XXXXX"

http://m.watchophilia.com/photogallery/bulovas-1917-1929/a1917-rubaiyat2/

 

This one starts with "40XXXXX"

http://www.mybulova.com/watches/1920-precision-6467

[/quote]

I'd say that both watches don't fall in line with the same manufacturing plant of the other early Bulova watches marked with either a globe or shield, as the case stamp is different from the norm, so they may have been from a different casing plant. Again the cases I'm referring to for the serial number sequence are all stamped American Standard and not American Standard W.C Co. And have either the shield or globe hallmark.

 

 

mybulova_admin
Posted February 5, 2016 - 8:35pm

In reply to by mybulova_admin

further to this....the second number in the Rubaiyat case serial numbers may indeed relate to the year of manufacture, as we only see them in 27xxxxx, 28xxxxx and 29xxxxx (not including solid gold) models. This could translate to 1917,1918 and 1919.

Why the earlier Rubaiyat watches started with a '2' and the later Lady Maxim's started with a '1' is something I'm still investigating. 

Still just a theory at this stage.

mybulova_admin
Posted September 1, 2014 - 11:53am

 

Again look at the watches starting with a '1' and tell me if you find any that start with a 14 15 16 17 18 etc.

mybulova_admin
Posted September 1, 2014 - 12:05pm

 

Oops I should have check before my last comment. Good news is though I think I'm on to something as we do in fact have watches with 14 and 15 as the starting case serial number and they basically correspond to that year... 1924, 1925.  Again bear in mind that a case and movement may have been manufactured in different years. It would be perfectly logical and acceptable for a 1924 movement to be in a 1925 case.

mybulova_admin
Posted September 1, 2014 - 12:24pm

 

Bobbee, from all your own research you can see that 1921/22 was a busy time for Bulova in the marketing/newspaper department. It makes perfect sense that the only way Bulova could have done this would be to hit the ground running (so to speak) and the only way they could have done that is to do a mass manufacture pre 1921. I'd imagine it took a fair bit or organization and time to manufacture so many watches in such a short period to show them to market the way they did as a relative new comer into the watch market.

 

mybulova_admin
Posted September 1, 2014 - 1:32pm

 

OK to summarize what I'm proposing. Cases marked with American Standard and either the globe or shield and having a case serial number starting with a '1'.

  • 10xxxxx - 1920
  • 11xxxxx - 1921
  • 12xxxxx - 1922
  • 13xxxxx - 1923
  • 14xxxxx - 1924
  • 15xxxxx & 5xxxxxx - 1925
mybulova_admin
Posted February 5, 2016 - 8:40pm

In reply to by mybulova_admin

Also now proposing the following for Rubaiyat branded watches.

  • 26xxxxx - 1916
  • 27xxxxx - 1917
  • 28xxxxx - 1918
  • 29xxxxx - 1919

Cases marked:

AMERICAN STANDARD
W.C.Co
WARRANTED
25 YEARS

bobbee
Posted September 1, 2014 - 3:03pm

This makes sense now.

I have checked all of Lisa's watches 1917-1923, apart from those not following the formula Stephen puts forward, all conform to this.

Example:- 1920 Rubaiyat- Case SN=1065905 - Movement=AI - Movement signature=Bulova W. Co.-  Case Signature=American Standard+Globe.

Formula as in Stephen's post above this is viable with twenty-two watches in Lisa's Database, dating from 1918-1923.

Where possible, I have checked the myBulova database and apart from a couple of anomalies, it also conforms to the formula.

 

Well done Stephen, now sort the DB out! ;-)

William Smith
Posted September 1, 2014 - 4:14pm

This is great.  I know these case serial numbers have meaning of which we are currently unaware.  What a good woriking theory.  I'll go through some of our records.  It's nice having access to Lisa's examples too, as the more data the merrier (or more robust anyway).  Good job everyone!!

When we have- by agreement- what may be reasonable sample size, we can put forth the idea to update database records based on results, or continue to monitor.  This is just too cool.
 

bobbee
Posted September 1, 2014 - 4:57pm

Stephens idea of Bulova churning out loads of cases in the 1920 timeframe is good too.

I'm thinking that this is the time of the Rubaiyat being sold in larger numbers, so Bulova then start to make their own movements using other companies ebauches instead of simply stamping the bridges of bought-in movements with "Bulova", or "Rubaiyat", and leaving the original makers company marks. These early watches were, I think, simply fulfilling a need in the market at the time, a way of making money on a popular but (thought to be) short-lived fad, the wrist watch.

Bulova  are around 1920-1921 beginning to realise that wrist watches are the future, and advertising is the way to get these models shown to the masses. Dipping his toe a little deeper, but still not commiting the parent company name to the endeavour, he releases the Hudson /Lady Maxim lines. Inside each is a Bulova-signed movement, and when popularity of the wrist watch expands, the time is ripe for the Bulova name to take it's place in the adverts.

mybulova_admin
Posted September 1, 2014 - 5:26pm

Amen to that! I really think that this 1919-1920 period is very significant in Bulova's history as one of America's most successful watch manufactures.

I'm very excited that we may have finally cracked a large part of the puzzle surrounding the early pieces. I just knew the case serial number had to hold some sort of secret which is why I finally went looking. Glad I did now.

As Will said, if we can all come to the general consensus that this idea is correct then we can forge ahead and fix up the Db as Bobbee said. It'll certainly make things so much easier in dating these early models.

Alex
Posted August 17, 2015 - 11:47pm

I like the hypothesis and did a statistical check in the main databases for ladies watches.

My findings (the case numbers are the first two digits of the case serial, followed by the number of watches I found, and yes, there are cases starting with 16, and one movement with a double date code 24/25):

case   no date code    1924     24/25     1925   1926

13             8                   5           -             -           -

14             -                    6           -            1           -

15             -                    7           -            1           -

16             -                    2           1           3           -

So you see that the majority of 15 cases actually have a 1924 movement. And the 16 cases do not come with 1926 movements, but is kind of 50/50 split between 1924 and 1925.

Then I did a double check on cases starting with 4 and 5, which according to the case dating convention stands for 1924 and 1925:

case   no date code    1924       24/25      1925     1926

40                 -                    6           -             2           -

50/51/52       -                    -            -            10         3  

The second digit of the 4 cases is always a 0. For me this is an indication that the start of the new coding system happened during the year and likely in the second half. Otherwise there would be 41 cases. The 5 cases come with 50, 51 and 52. This seems to be representative of a full year, since of 1926 we find 64, 65, 66 cases, so also 3 series starting with 6 in total. The 4 cases with a 1925 movement and the 5 cases with a 1926 movement could be explained as a normal "statistical error" as a result of movement swaps over time. And maybe Bulova actually mixed two years while assembling the watches in the December/January period as a result of stock differences between cases and movements at the end/beginning of the new year.

So, zooming in on the 15 and 16 cases, I believe that the second digit does NOT stand for the year. I think they were originally 1924, with 16 cases being "borderline", before Bulova switched to the new date coding system for both movements and cases in 1924. I do believe that initially the second digit might have stood for the year for the 11, 12, and maybe 13 cases. But it limits the total number of watches to only 100,000 units per year given the total 5 free available digits of the total 7 digits. I guess that by 1924 Bulova went over that limit. The highest 40 number I find is 4075808. So, if all 14, 15, 16 and 40 cases are from 1924, and all numbers are indeed used, then Bulova must have sold 375,808 watches in 1924. That sounds plausible, also looking at 1925 and 1926 volumes based on their respective serial numbers.

And thinking about it further, I actually believe that the increasing sales numbers forced Bulova to rethink their coding system in 1924. Instead of the second digit being the year, they moved it to the first digit and dropped the "1" as first digit. This gave them back a logic in the serial numbers, and increased the theoretical number of watches per year to 1 million instead of 100,000. So a new (near) future proof system.

The only question that remains: why didn't they do this from the start? Why insist on this first digit being a "1" during the initial years?

 

 

William Smith
Posted August 26, 2015 - 12:50am

In reply to by Alex

[quote=Alex]

Then I did a double check on cases starting with 4 and 5, which according to the case dating convention stands for 1924 and 1925:

case   no date code    1924       24/25      1925     1926

40                 -                    6           -             2           -

50/51/52       -                    -            -            10         3  

The second digit of the 4 cases is always a 0. For me this is an indication that the start of the new coding system happened during the year and likely in the second half. Otherwise there would be 41 cases. The 5 cases come with 50, 51 and 52. This seems to be representative of a full year, since of 1926 we find 64, 65, 66 cases, so also 3 series starting with 6 in total. The 4 cases with a 1925 movement and the 5 cases with a 1926 movement could be explained as a normal "statistical error" as a result of movement swaps over time. And maybe Bulova actually mixed two years while assembling the watches in the December/January period as a result of stock differences between cases and movements at the end/beginning of the new year.

[/quote]

So for the ladies double-check from above,  6 of the 8  cases starting with #40 housed movements from 1924,  and 2 cases housed 1925 movements.   Those two records which contained the 1925 movements are possible movement swaps?   Is there any other evidence/information in the two records which suggests there could be a movement swap for those two exceptions?  

And 10 of the 13 cases starting with the #5's housed 1925 movements.  The 3 which housed 1926 movements could be explained by possible movement swaps?  Same question as for above- for those 3 exceptions, was their any info/evidence in each of those three watch records which suggest movement swaps?    

Since we are allowing for some movement swap error (e.g. for those 2 of 8 records in 1924), should we apply that same probability of error to the records which had a correct match between case # and mvnt year?   If we are saying 25% of the records/samples could be mvnt swaps,  it seems like that probability would apply equally to those other 6 "correct" records too.  

The odds of movement swap could result in some of those correct/matching case/mvnts having had a swap too.  Even though they now house matching year movements, a few of those could have been from a swap which just happened to be with a matching year movement.  

Maybe the two "outliers" are as original, and two of those 6 with matching case/year are actually attributed to mvnt swap w/ another matching year mvnt. 

I'm  trying to think how this error probability would relate to all samples, not just the outliers. 

 

Geoff Baker
Posted August 26, 2015 - 6:25am

I guess Edmundo's (Alex) research leads me to a couple of possible conclusions:

* Our current hypothesis regarding post 1925 serial numbers indicating year of production (first digit of serial indicates year of production) is sound and could be be stretched to include at least some 1924 cases. 

* A theory that the second digit of pre 1925 serial numbers indicate year of production might not be   supported.

Thanks again Edmundo for the data, well done.

Alex
Posted August 26, 2015 - 7:09pm

Thanks Geoff, see also http://www.mybulova.com/forums/where-are-1927-bulova-ladies-watches

Here I state that for 1927, the first digit is not representative either. The case signature seems to be more indicative of the year of manufacturing in combination with the movement date code. Maybe also a result of too many watches sold in 1927, so the current system did not supply sufficient "serial numbers" to keep up with the sales? Any one has the sales revenue numbers of Bulova in those years?

Alex
Posted November 24, 2015 - 7:54pm

An update on the statistics, based on new watches found, further reinforcing that cases starting with 13, 14 and 15 the majority contain 1924 movements:

case   no date code    1924     24/25     1925   1926

13             8                   5           -             -           -

14             -                    7           -            1           -

15             -                   10           -            1           -

16             -                    3           1           4           -

William Smith
Posted November 25, 2015 - 2:53am

Thanks for the update Alex.  As we find more examples, it helps us see patterns - and with these new watches, reinforces the patterns you noted to date.  Cool