I just finished reading High Grade Columbus Watches Part 2 in the April Bulletin. Scholarship like that adds real richness to the hobby.

There’s one thing that I hope the authors or others can clarify for me. It says (pages 230 & 231) that some Railway Kings, Columbus Kings, and Ruby’s weren’t adjusted for isochronism. To me this seems hard to imagine, for two reasons. First, it’s my understanding that “adjusting” for isochronism is largely about having a lever escapement, a Breguet hairspring, and a competant mainspring, and I believe these movements had all of these. Second, these movements were acceptable for railroad time service and it seems unlikely that railroads would have accepted movements whose accuracy at the end of the day might vary appreciably from their accuracy at the beginning of the day.

What am I missing here?

I think the problem may be one of interpretation. The reference on p. 230 refers only to numbered grades, and not to any of the named grades. I believe that all of the Columbus King, Time King, Railway King and Ruby grades were adjusted to isochronism, although we have not seen factory documentation for all of them. In Table 1 on p. 231, due to layout constraints, all of the named grades occupy two lines in the table, but the adjustments are listed only on the first line. Adjustments were the same for the hunting as well as the open face versions.
Hopefully this may clear up some of the confusion caused by the column.

Ed Ueberall
NAWCC #49688
IHC #34
http://members.aol.com/stdwatch/

“The reference on p. 230 refers only to numbered grades, and not to any of the named grades.”

Since we believe that all of the Columbus King, Time King, Railway King and Ruby grades were adjusted to isochronism, Table 1’s idiosyncrasies aside, let’s focus on the numbered grade movements that were suitable for railroad time service. What I’m struggling with is: since they had lever escapements, Breguet hairsprings, and presumably competent mainsprings: in what sense were they not “adjusted to isochronism?”

Thank you for indulging my ignorance on this issue!

Not Ignorance but a healthy curiosity! We've all heard that curiosity killed the cat but I'd say our favorite pup is accumulating knowledge. In fact we're all learning something new every day.

Serial Number 505012 is a fully adjusted for RR Time Service 21-jewel Columbus King...

On the numbered Columbus grades, the factory published descriptions listed the highest grades (those with the lowest grade numbers) as being adjusted to isochronism, along with temp & positions, while the description of the others omitted the isochronism adjustment.
Why? We really don't know. Possibly it was a marketing strategy to differentiate the higher grade movements, perhaps the lower grade movements had a lower quality mainspring that varied in power transmission enough to make isochronal adjustments more difficult. In any case, the lack of isochronal adjustment was based on factory published specs.

Ed Ueberall
NAWCC #49688
IHC #34
http://members.aol.com/stdwatch/

This discussion’s really interesting!

I wonder: if a person had enough time, curiosity, and original movements, would it be possible to examine the mainsprings – markings, design, length, width, thickness, material – and determine whether or not the lower grade movements had lower quality mainsprings that varied in power transmission enough to make isochronal adjustments more difficult?

Wow! that’s a good-looking movement Lindell! According to Shugart’s Columbus section only the Columbus Kings and the Railway Kings had the happy combination of raised gold jewel settings (raised gold jewel settings strike me as textural, form-following-function) and no two-toning (two-toning strikes me as gaudy, form-unrelated-to-function).

I just picked up this thread and noticed that "Dog" mentioned a Bruquet hairspring as a requirement for adjusting to isochronism. That is not always so, as all E. Howard watches were adjusted to isochronism and none except for the split-plate versions had the Bruquet style hairspring.
Just thought I'd muddy the waters a bit.
Harold

Thanks Harold! I’m trying to understand more clearly what “adjusting for isochronism” means. I’ve read Wayne Schlitt’s Isochronic Adjustments and Fried’s Watch Repairer’s Manual and Bench Practices.

Just because a watch has a Breguet hairspring and a good quality mainspring, does not mean it's been adjusted for isochronism. Such a watch would probably have the POTENTIAL to be adjusted for isochronism, but that doesn't mean someone has actually taken the time to adjust it.

In watches with Breguet hairsprings, isochronal adjustment is accomplished primarily by changing the shape of the overcoil. Generally speaking, bringing an overcoil closer to the center axis (staff) will increase the rate when the balance amplitude is low, while moving the overcoil more toward the perimeter will have the opposite effect. Unfortunately, every balance and hairspring is different, so that each has to be individually adjusted if highly accurate rates are expected.

In watches with flat hairsprings, isochronal adjustment is accomplished primarily by manipulation of the regulator pins. Wide spacing between the regulator pins will tend to allow slower rates when balance amplitude is low, while minimal space between the regulator pins will tend to have the opposite effect.

For what it's worth, I have a 23j RWK, and like Lindell's Time King in the image above, it does not have gold jewel settings. I've always wondered about the reasons for that, but I'm not sure ANY Columbus watches ever had gold jewel settings.

Steve Maddox
President, NAWCC Chapter #62
North Little Rock, Arkansas

Thanks Steve! Makes more sense to me now.

I won’t be doing any adjustment; I’m happy to leave it to the pro’s. I just enjoy trying to understand. So I always appreciate folks who add to my understanding.

Kinda like the infield fly rule. I don’t expect to be applying it between the white lines, but knowing it adds to my enjoyment of the game.

Regarding gold jewel settings I was just parroting “GJS” from Shugart. Maybe there should be another designation like say “GCJS” for gold-colored jewel settings?

Real gold jewel settings (as well as balance screws, train wheels, etc.) usually have a distinct pink color, and they're always highly polished.

In an attempt to imitate the appearance of gold settings and balance screws, some companies used a copper alloy that can be polished to look like gold, but in time, it loses its lustre.

===============

Steve Maddox
President, NAWCC Chapter #62
North Little Rock, Arkansas

Risking a slight topic veer: I’ve added Steve’s 23J Riverside Maximus (and the Dudley) to my list of high-grade American pocket watch movements with friction jewel settings (23J Vanguard; 21J BWR Grade #571).

Which raises the question: what accounts for the incidence of friction jewel settings (instead of screw-on’s) on low-grade and high-grade movements?