Illinois Bunn 18s 17J - Model 6 with Anti-Magnetic Hairspring

[Nigel Harrison]

Hello,

I have picked up this 18s Model 6 Illinois Bunn 17J (first pattern) and it has a white harispring. I am guessing this is an Anti-Magnetic hairspring, and I am guessing it is probably added at a later date? Any thoughts?

What does make a watch Anti-Magnetic? Is it just the white Anti-Mag hairspring?

Also, I am guessing this is the incorrect dial since it is not Double Sunk? even though it does look railroad style. Do people out there agree it is not correct for this model of Bunn?

Thanks and Regards,

Nigel Harrison.

[Fred Hansen]

Hi Nigel -

I think you are right and it looks to me like a non-magnetic hairspring that is matched with a regular Bunn grade bimetallic balance wheel with gold screws. But for any intended non-magnetic watch I would expect to see a non-magnetic balance wheel along with the hairspring.

The only original non-magnetic Illinois watches of this era I'm aware of are those that were made for the Paillard Non-Magnetic Watch Company of Chicago. These have a white non-mag hairspring but they also have a non-mag balance wheel, roller table, and lever. The non-mag balance wheel is bimetallic but both metals are usually silverish in color and the rim of this wheel looks much different than a regular wheel.

In much later years the non-magnetic Illinois watches were the Bunn Specials equipped with Elinvar balances that were made at the end of the Illinois Watch Co.'s history while it was under the Hamilton Watch Co.'s ownership.

I don't think I've heard of any other non-mag Illinois watches but would be interested if there was something new out there.

Fred

[Fred Hansen]

Here is a photo of a 21 jewel Bunn Special grade that was private-label marked for Paillard and has the typical non-magnetic components. Things to notice here are the white hairspring, silver colored balance rim, and another interesting note is that the watch does not have the typical high grade gold colored balance screws that would be expected in a Bunn Special private-label ...

[Fred Hansen]

I would definitely expect your watch to have come with a double-sunk dial originally.

The only two times I can think of where I'd not question a non double-sunk dial on an 18 size Bunn grade watch are ...

1) Some of the very early (early to mid 1870's) gilt movements with a sunk-seconds "Springfield Watch Co." or "Illinois Springfield Watch Co." signature and of the appropriate style

2) Later watches with an original Swiss made Ferguson dial. This style of Ferguson is actually a one piece enamel dial with recessed areas for the center and seconds but does not have true separate sinks.

The dial that is on your watch is a style I would expect to see on a lower cost 15 or 17 jewel model, and I'm pretty sure I've seen this dial most often with the 17J grade 69 Illinois movements.

Fred

[Nigel Harrison]

Hi Fred,

Thanks as always for responding to my posts. Yes I agree with everything you say and it is good to confirm my thoughts. Nice Non-Mag movement you posted as well, I don't think I have seen one of those with the patent regulator - very cool. That is interesting that the balance screws are non-gold, maybe they are required to keep with the whole non-mag theme.

Thanks and Regards,

Nigel Harrison.