I’ve never seen an 18S Hamilton close up so I ask this out of ignorance.

I figure that 18S Hamiltons must have micrometric regulators because they’re on Webb Ball's railroad-grade list

But I associate micrometric regulators with screw- or star- devices, and in drawings and photos of 18S Hamiltons I don’t see anything I recognize as a screw- or star- device.

And I notice (Shugart 2002, p. 150) that the 18S Hamiltons that Webb Ball put his own name on have obvious screw-type regulators instead of the usual Hamilton ones.

Do 18S Hamiltons have micrometric regulators? How do they work?

Thank you very much!

The whole point of having a micro-metric regulator is to have a combination of fine adjustment and the holding of spring tension against it so it will not move if subjected to a sudden jolt or slam. For that reason, they were a basic requirement on RR watches.

Hamilton 18-size RR grade watches have the style of regulator you see below in this picture. See the head of the adjustment screw at the end of the red arrow in the foreground? It will be pretty obvious to you how they work by simply examining this photograph. You'll see there is a scale for the reading the setting way over on the other side.

The reason you haven't "gotten it" before is because the movement is almost invariably photographed from the opposite side. There the lettering faces you, but you would not see the screw and therefore be unable to comprehend the design.

Ball-Hamiltons used a far more conventional design in accordance with Webb C. Ball's strong belief in simplicity.

Hope this helps!

Lindell

On these two movements below you can readily see how simple and effective a micro-metric regulator can be. The 17-jewel South-Bend on the left has one, whereas the 7-jewel on the right does not. Unlike the Hamilton above this South-Bend design kept parts and thereby complications to a minimum.

Thanks for the super tutorial Lindell.

It occurs to me to wonder: what was the earliest micrometric regulator?

I love this site.

Lindell,
I was wondering what the 217 and 203 marked on the two movements indicate? Could it be model numbers? or grade? Great picture of the Hamilton regulator. Thanks