Draw your own conclusion
In our last episode your local horologist was confounded by the "seconds" dial of the Vienna single-weight Regulator.
Some of the answer to this conundrum lay in the history of the manufacture of these clocks.
The very earliest models of what became this classic style were created in about 1780 in Vienna. They were hand made by individual clockmakers and often of amazingly high quality. The style grew in popularity, over time evolving into several distinct variants matching the tastes of the times.
Of those of you familiar with Viennas the first image you might have when thinking of a one might be something more... ornate than our example.
Perhaps something like one these:
Our Vienna is a bit more... modest in design.
Again a photo as it was found on the wall when YLH first saw it.
In that regard the observant reader / follower of this blog (thank you) might have noticed this tidbit from YLH's first posting about this clock, noted in its earlier owner's receipt.
The seller of the clock described it as a "Biedermeier" which was a distinct style of Viennas that corresponds to a well known period in the earlier part of the 19th century (circa 1815-1848) where clocks and many other types of furnishings were made with simpler lines and a more minimalist style of ornamentation.
In fact our Vienna has many of the features of that era.
Except that our Vienna was almost certainly made after that period and was almost certainly made in Germany not Austria.
As were the majority of Viennas!
Turns out that in around 1850 the now very well established German clockmaking industry moved to capitalize on the growing popularity of Viennas and started creating their own factory-made versions, perhaps not quite equal to the Viennese hand-made models but of very high quality nonetheless.
How can one tell that their Vienna is actually German made?
Some typical features of German / factory made clocks include...
- The movement is mounted on a metal bracket not a wooden seat board: Check
- Serial numbers and/or makers marks on the back plates: Check
- Escapement anchors have adjustable / Vulliamy-style pallets not fixed ones: Check
- Dials commonly incorporated "subsidiary seconds dials": Check
So our clock is almost certainly of German make but didn't they start making them after the Biedermeier era?
Yes but that style was quite popular when the German's got going and continued to be so during what was called the "Transitional" period of Vienna clock making from 1850-1875.
Ah.
YLH will not bore the reader with endless details but he strongly suspects that our Vienna was made during the latter part of the Transitional era in a German factory, likely either Lenzkirch or Gustav Becker.
But let us go back to the observation of the "seconds" dial.
Why is YLH dwelling on this point?
You see almost all variants of Viennas, Austrian and German, have 80 beat pendulums, meaning that the pendulum swings 80 times per minute.
The pendulum does not swing at a rate matching seconds. In fact, most clocks do not have pendulums that beat every second.
But here now is the difference that points us back to the head scratching of your dumbfounded horologist.
The German clocks emulated the style of the original Viennas and kept the 80 beat pendulums BUT they incorporated different escape wheels.
So?
What does this all mean?
Stay with this horology historian just a bit more.
Typically in most clocks, regardless of the BPM of the pendulum, the rest of the gearing of the clocks wheels ends up so that the escape wheel does one full rotation per minute.
For clocks built with a seconds dial one classic way to display / power it is to lever the escape pivot.
Frequently seconds hands are attached to the pivots (the tips) of the escape wheel arbors thus forming the mechanism to turn the seconds hand as that pivot will make a full rotation once per minute.
As an older example, readers might remember the Claggett clock YLH had the honor to work on. Here is a close up of its seconds dial.
Its seconds hand is attached to the pivot of the escape wheel.
See the image below. The anchor is over the escape wheel. The escape wheel arbor extends through the front plate and then the dial to end up protruding just enough to attach the seconds hand.
As does the arbor of the escape wheel of our Vienna.
YLH noted this in our first posting.
So we have examples of two clocks where the pivot of the escape wheel is used to turn the seconds hand.
Now back to the original Austrian Vienna clocks. They utilized 40 tooth escape wheels with their 80 BPM pendulums.
Meaning what?
A bit of math and horology...
All escape wheels move forward 1/2 of a tooth per swing left or right (beat) of the pendulum. Slow motion example here.
Two beats of the pendulum will move the escape wheel one tooth forward.
An 80 BPM pendulum ÷ 2 beats = 40, one-tooth turns of the escape wheel per minute.
40 one tooth turns ÷ a 40 tooth escape wheel = 1 full rotation of an Austrian escape wheel.
So a 40 tooth escape wheel of an Austrian Vienna clock makes 1 full rotation per minute.
German clocks... and here is the pièce de résistance...
use 30 tooth escape wheels with 80 BPM pendulums.
Again lets do the math:
All escape wheels move forward 1/2 of a tooth per swing left or right (beat) of the pendulum. Check.
Two beats of the pendulum will move the escape wheel one tooth forward. Check.
An 80 BPM pendulum ÷ 2 beats = 40, one-tooth turns of the escape wheel per minute. Check.
40 one tooth rotations ÷ a 30 tooth escape wheel = 1.333... full rotations of a German escape wheel per minute!!!
What the in name of timekeeping is that about!?
On the face of it this seems like an error or some crazy design.
No surprise that this is not an error. In fact this fast seconds dial is common in Viennas and common knowledge in the Vienna historian circles but was new to YLH.
But again, why this seemingly silly design?
Exploring this conundrum further YLH dug up an essay in the Bulletin archives of the NAWCC.
Author and German clock expert, the late Doug Stevenson produced a wonderful, deeply researched and humorously written article about this very issue titled "Seconds Thoughts on German Viennas." If any of you are members you can read it here. For others who are interested, shoot me an email.
Stevenson cited questions being mailed in to the NAWCC nearly 70 years ago from puzzled readers asking about Vienna clocks that had seconds hands turning too fast.
He begins the article with a story of a neighbor visiting who noticed a Vienna that Stevenson had recently restored.
"There's something wrong with that clock" said the neighbor.
The essay is delightfully written and it turns out, summarily, there are no absolutely assured explanations for this "design."
But most German-made Vienna Regulators that had a seconds dial were built this way.
Of all the various factors Stevenson reviewed the one that made the most sense to YLH were the issues of economics.
Consider: At that time seconds dials were considered an ornamentation. Clocks don't typically beat to seconds and these pendulums didn’t. Competition in the industry was fierce and most German factories at that time were already tooled to build clocks with 30 tooth escape wheels.
Retooling a factory and rebuilding a whole new anchor design for a deadbeat escapement with a 40 tooth escape wheel was no small thing to do and likely the big makers simply considered such an change to be not needed nor cost effective.
In the February 1960 issue of the NAWCC Bulletin, Vienna expert Dana J. Blackwell published an essay discussing this same issue and noted:
"Apparently the seconds hands were thought to be selling points, but the difficulties involved in making small Graham escapements with forty-tooth scape wheels having correct clearances were considered too great to bother with by German makers."
Stevenson also notes that clockmakers of the time didn't even advertise "seconds dials" for customers who wanted them. They called them "kleine Secund" which translates to "little seconds."
And for those that really wanted accurate seconds dials there were options for customers to buy Regulators:
Of course not everyone agreed with this approach of leaving most Viennas with this timekeeping oddity. Stevenson cites a letter sent in to a then new German clockmakers journal, "Deutsche Uhrmacher-Zeitung", published July 4, 1877 where an unidentified clockmaker asked the same question about the fast seconds dial.
And the following issue of the DUZ a clockmaker, "G.T." wrote a response to that question stating that he thought it was:
"“... just ridiculous” for someone to sell a clock with the “high-sounding name regulator” which has a seconds hand that doesn’t make a round in one minute. “In order to remedy this Unding,” this absurdity, “all colleagues” (i.e., all clockmakers) “when buying ¾ regulators with seconds hands should insist that only movements that have 40-tooth escape wheels be sent.”"
Yeah. 45 seconds. Should have raised some horological flags right there.
But... the implications of that observation didn't hit the right synapse in YLH's limited brain at the time.
Comments
Post a Comment