View Full Version : time piece jewels

13th Dec 2017, 21:56
When I were a lad, before the Daniels co-axial escapement, a decent time piece without complications (tourbillon, stopwatch, moon phase etc) would be proud of having 17 jewels. Today I saw an advert for a watch which is being marketed to pilots through one of the UK flying organisations and from a company founded by a US pilot which boasts of having 4 jewels. A bit odd, I think, an even number of jewels suggests that arguably the jewel that does the most to improve performance (pin on the balance which nudges the escapement) is not jewelled.

Why would you boast about such a lowly number of jewels?

I won't be forking out 250 ish for one anytime soon.


14th Dec 2017, 07:44
Why would you boast about such a lowly number of jewels?

Would it be a high number for an electronic watch?

14th Dec 2017, 08:20
A woman is more interested in the size of your jewels, not so much the quantity.

Loose rivets
14th Dec 2017, 22:12
Pah! I have 375 on mine. Mind you, that's spread over 25 7A series Seikos.:}

15, Four synchronous motors and four gear trains. A wonderful 80's decade. Then came the frighteningly awful 7T series, which nearly caught me, but being predisposed to doing up things saved me.

Now there's a Grand Seiko, with a much higher spec, and a much higher price.

15th Dec 2017, 07:43
Rans6.. that would be a quartz watch I think. 17 jewels were common on mechanical watches.

Jewels were used to reduced friction/wear. Mechanical watches used gears with metal pivots and ran off a mainspring (think clockwork toys). Reduced friction meant that a weaker spring could be used which further reduced wear.

Early quartz watches used lesser jewels ..typically less than 10. They could get away with this as the gears are not under constant load from a mainspring, instead they keep time by depending on pulses from the electronic bits. The gears are also made of plastic which then to run with less friction. Nowadays most of the cheaper quartz watches have no jewels at all so having 4 may signify a better movement.


15th Dec 2017, 13:28
Of course there are also "marketing" jewells, a while back saw a picture of a movement claiming 27 jewels with around 16 mounted on the back plate, pretty to look at but not at all functional.

Similar thing was sometimes found in early transistor radios where it was common practice to replace diodes with diode connected transistors to up the count.

15th Dec 2017, 17:12
I don’t think you will get many coaxial escapements for 250 somehow

16th Dec 2017, 00:00
Why did we have to go to watches that need batteries ? Winding by a large knob, or the movement of ones' wrist on a so-called "automatic" did the job quite satisfactorily, my watch battery gave up last week at a critical time for me, i.e. in the middle a 12 hour trans-pacific flight, albeit only as a passenger, but no battery replacement service provided by the cabin crew.

Once flew with a Captain who wore no watch, he reckoned that one always knew the time approximately, and one knew how long it took to walk / drive from home, having checked the precise time before departure for any given bus, train, appointment. He said that the only time he needed a precise time piece was when flying, and Boeing had provided a clock on the instrument panel in front of him.

Can't agree, I was surprised how often I looked at my "dead" watch. Fortunately a new battery did the trick, and my 40 yr. old analogue Seiko watch is doing sterling service again.

Loose rivets
16th Dec 2017, 01:01
I've just worked on a Seiko auto charging watch. A 3M22A. I rather thought the battery was shorted as my pal had just replaced it yet it was reading zero. The old one still had .7v so something was wrong.

It was a heck of a footle to change it though I could do it again much more quickly. After the weight and wheel were removed there were two pressed metal bits to get out of the way, each with their own insulator that would vanish if you breathed on it.

Yes it is a battery. The capacitors are generally being done away with, but I still think having a huge flywheel thingie in there is daft. Perhaps not with the self winding ones, cos you had a knob as well, but these, well, the number of shakes for 2 days of operation is only suited for use by a teenage boy. :p

Alpine Flyer
16th Dec 2017, 21:39
Why did we have to go to watches that need batteries ?

We don't. Citizen produces nice watches that run on solar power, even radio controlled ones. Mine is about 10 years old and never stopped. It has two weaknesses, though. The minute hand loosens when one hits something with the watch or when it falls to the ground and I once had the crown come loose as the internal "axle" connected to the crown is rather minuscule. I am sure both problems could be rectified without ditching the solar power concept. I have not been tempted to replace it, but if I were, I'd take a titanium model which is a lot lighter.

16th Dec 2017, 23:41
This thread prompted me to retrieve my early 1970s Sicura (non-battery) automatic, which I've not used for very many years and has been lurking in my sock drawer. It started up straight away with a couple of winds and seems to be keeping good time, despite never being serviced since the day it was made, about 46 years ago. It boasts 25 jewels, all of them inside the case, as far as I can tell.

The maker of Sicura watches took over the name Breitling when its previous owner was about to close the factory.

17th Dec 2017, 15:56
I remember one time in 1968 I took my Seiko whose glass I had scratched into the Seiko agents in Kowloon. I handed it over and was told if I cared to wait they would give it a clean and service at the same time. The watch was handed to one of the people working behind the main desk. It was stripped and the movement was cleaned and lubricated. A new glass was fitted and the watch returned to me. Time taken - 10 minutes. Charge - one Hong Kong dollar! Wore that watch for years - when I became a nav and was issued with an Omega I discovered that my 10 Seiko was more accurate, so the Omega hardly every got worn. I sometimes see those wind up Omegas on ebay, always described as pilots' watches, I notice, in spite of the absence of Mickey Mouse on the face! People seem happy to pay several hundred pounds for them - I hope nobody gets mine, it was rubbish!