A Rare Rotherham and a bit about hairspings & balances.

A Size 12 Rotherham for Hoefler &
Co of Devenport. 19 Jewels, 1901.

This is at first sight a normal high end size 12 Rotherham with 19 jewels but two things make it unusual, first is still has an original watch paper in the back as described in my last post, but more important is the very rare balance assembly.

Normally these movements have a cut compensating balance with a normal steel Breguet hairspring, however in the late 1890's a new alloy known as "Elenvar" was devised by Charles Édouard Guillaume (who got the 1920 Nobel prize for physics for the development), its key property was that unlike steel its flexibility (modulus of elasticity) did not change with temperature. When used as a hairspring it removed the need for a compensating balance.

A very rare solid balance with an
Elenvar Breguet hairspring.

Most companies implemented the Elenvar hairspring with a screwed balance which allowed the balance to be balanced fairly quickly (as a car wheel with a new tyre) and the weight and number of screws could be used to adjust the moment of inertia to match the hairspring to make the watch run too time. 
 
With this movement Rotherham tried a different route and used a traditional 3 armed solid balance which is probably gold. Balancing and tuning was done by removing slight amounts of material from the balance as can be seen from the picture to the right..

This is the only watch I have seen with this arrangement and it is likely that Rotherham only made a few, probably because the amount of skilled work required to set up the balance would more than likely have made it more expensive than the normally sprung cut compensating balance.

A rare pair of papers.

click the picture for a larger view

It is very rare these days to find watches with watch papers intact (they are collectable in their own right), I had only 2 or 3 from the last 600 watches. And today two turned up together, I knew one was coming but the second was a nice surprise.

 

The papers were used for advertising and would have been put in by sellers or repairers and occasionally you find a watch with a stack of them but usually they are glued together, to the case and / or are falling to pieces. Both of these are original to the watch and have the same retailers names as are shown on the watch faces.

 

The blue one is on a Rotherham from 1901 retailed by Hoefler of Devonport. The watch itself is something rather special - watch this space!

The red paper is on a Waltham 1908-610 half hunter sold by Harral of Barnsley, it has the serial number of the movement on it and is dated 11 years after the watch was made so presumably they were warranting a repair or they had bought back the watch and had resold it.

Dating Movements by Cyma & Tavannes

I recently had a query on dating these movements so have posted the answer here so I'll not have to do it again.

The serial number on these movements are under the dial as show to the right. My dating is based on a reasonable number of watches, listed below, in hallmarked silver or gold movements. The sample is heavily biased to watches retailed by J.W. Benson, largely because other retailers frequently used Swiss hallmarked silver cases which do not carry a date mark. Benson appear to have switched from Revue to Tavannes in about 1932 the database is only good for the 1930s.

It must be remembered that a movement might not go straight into a case which itself may have been on the shelf for a while so there will be some overlap, also the hallmarking years of the various assay houses are not in line with each other or the with calendar but the difference is small and the date is likely to be accurate to plus or minus a year.  (updated Feb 2017)

Serial	Date
4,322,549	1908
12,487,883	1919
14,708,666	1919
13,079,475	1921
14,262,246	1924
15,485,579	1926?
15,485,952	1926?
15,939,146	1926
17,482,498	1929?
16,624,975	1930?
17,865,828	1932
17,886,973	1932
17,888,724	1932
17,888,811	1931
17,889,975	1932
17,899,152	1931
17,899,219	1932
17,889,918	1932
17,902,501	1932
17,903,525	1932
17,903,625	1932
17,908,930	1932
17,909,034	1932
17,909,035	1932
17,944,833	1933
17,944,871	1933
17,966,044	1933
17,970,131	1933
18,045,354	1935
18,045,567	1935
18,050,727	1935
18,052,802	1936
18,055,283	1936
18,055,497	1936
18,055,498	1936
18,055,544	1936
18,066,750	1935
18,070,392	1936
18,076,649	1936
18,090,883	1936
18,112,605	1937
18,112,379	1936
18,113,219	1937
18,141,556	1937
18,146,434	1937
18,146,664	1938
18,199,372	1937
18,240,750	1938
18,245,978	1938
18,246,001	1938
18,252,273	1940	Benson stock?
18,253,220	1939
18,256,774	1938
18,265,158	1938
18,268,000	1940
18,276,566	1947?

J.G. Graves The "Express English Lever"

The "Express English Lever" signed by
J.G. Graves and hallmarked 1902.

John Graves was an important man in Sheffield owning a substantial department store and mail order company later part of Great Universal Stores. Originally apprenticed as a watchmaker he also sold a lot of watches.

This is one of the most common found today, branded The "Express English Lever" and signed by him. Although it used standard full plate movements of the early 1890's it does have a couple of interesting aspects.

Firstly although it is English and does have a lever movement it is not an "English Lever" but has a "Swiss lever" escapement laid out tangentially in the manner of the "English Lever".

3 years on the web and 688 watches.

Three years ago tomorrow www.oxfordpocketwatches.co.uk went live, I was up till then selling from display cabinets at three antiques centres and also through eBay and I had finally got round to setting up a web site to support them together with a Facebook page and four months later this Blog.

The Benson Hunter shown here is the five hundred and fifty-sixth watch to have been sold directly from the web site with a good many more sold from the display cabinets as a direct result of the web site.

Within 2 months I was selling more from the web site than through all three antiques centres combined. During November the web site had some minor customisation  to improve the graphics and sales were really taking off as Google and other search engines started giving good rankings.

Having started off with about 140 watches by the following April I no longer has sufficient stock to support three cabinets so I had to close first at Chipping Norton and then in November at Wallingford when I also changed from a full cabinet at Brackley to the half cabinet I have now.

Stock is now very low at 38 watches and although I expect that to improve when the fly fishing season ends It is unlikely that I will ever get above fifty or so as they sell too quickly and the supply of good watches to restore continues to decline.

Dating Pocket Watches.

Revised and extended December 2016 from the original post August 2015

Dating watches can be a problem but here are a few ways that it is done.

American Watches

A Waltham 1892-Vanguard dated
to 1902 by the serial number, but
probably re-cased (see below).

These are generally the easiest as for many makes, such as Waltham and Hamilton, production records are still extant and enthusiasts in the US have put a huge amount of effort into putting them into online databases so by taking the serial number of the movement (not the case number!) and entering it you can get the production date usually to within a year or possibly two but sometimes to within a month.

Details of the type of watch may also be provided although there are some errors largely due to mixed production runs (e.g. lever and pendant set, etc..) and the occasional transcription error. The original Waltham database is maintained by the NAWCC but the most comprehensive site I have found is The Pocket Watch database.

Swiss Watches

Are more problematic, of the makes I regularly deal with, Omega have published the dates that each million watches were produced so by interpellation the production date can be determined within a year or two. Dates are known for Zenith and some for Longines, & Baume.

A Cyma movement with the serial
number under the dial

For most of the other makes the data is not generally available or, as is the case with Revue Thomman, the movements do not carry a meaningful serial number, just a 2 or 3 digit number to identify watches within a batch of production.

Having had a lot of watches by Cyma and Tavannes I have been able to build up a good database of serial numbers vs date for production between c1930 and 1938 using the silver hallmarks (see below) which is now good enough to identify the date to within a year. See this post for details.

Beyond this is comes down to experience and identifying key features such as machine set jewels which determines the earliest possible date.

English Watches.

An LWC movement showing the
serial number under the dial
dated to 1897.

Are very difficult, as far as I know production records are only available for the Lancashire Watch Company and those that are not accessible.

Other makes (assuming you can identify the maker!) are difficult as several companies appear to have multiple number sequences, indeed occasionally an Errington will turn up with two serial numbers one from each major sequence.

Generally it is therefore necessary to reply on silver case hallmarks or when in a filled or rolled gold case to compare with previous dated examples which may not be as reliable.

Silver Cases.

Silver hallmarks for 1903 by the
Birmingham Assay. The movement
is a Waltham 1899-620 also 1903.

English silver and gold case hallmarks are unique in having a date year, although until 1974 this is not quite in line with the calendar year and varied by Assay house with the Birmingham "year" starting in July and the London "year" in May, normally I refer to just the starting year, so Birmingham 1908 would indicate that the case was assayed between July 1908 and June 1909.

Some Swiss watches have only the Swiss hallmarks but others have English import marks.

For older English watches this is generally a reliable method of dating but with the introduction of the standard watch case we start to have problems due to recent re-casing of orphaned movements into orphaned cases, a problem which appears to be getting worse judging from what I see on eBay.

A subsequent post here will look at  how to identify re-cased watches. See also J.W. Benson movements in Dennison cases.

Market & Stock Update July 2015

Demand remains high, particularly for English and high end American, unfortunately these are also the ones most difficult to get hold of and with the general shortage of watches available to me I am now down to 40 watches in stock. I have currently only got two English watches available and have sold out of true railroad watches (although I do have a few railroad grade). I do have some watches, mainly medium quality Swiss, awaiting restoration but it is going to take some time for the stock situation to improve and it may get worse before it gets better.

In UK, Fellows of Birmingham have stopped their quarterly specialist auctions of pocket watches and are now including just a few, mainly solid gold watches, in with their general watch auctions. On eBay volume is down dramatically from a year or so ago and the availability of quality watches is even further down.

I used to import watches from the USA, volume is probably down there as well, but I have had to largely stop imports. This is largely because eBay have encouraged sellers to use a newly introduced facility (from a third party I believe) that collects import duties in the USA so that goods come straight through UK customs.

Unfortunately not only is this frequently slower it is far more expensive. Previously, if charged at all, I would pay Royal Mail £8.50 handling fees and up to about 9% VAT, with the eBay system charges it is more than double.

As an example a watch currently listed in the USA on "buy it now" is listed at $320 plus $15 postage plus a whopping $90.37 "duty" and handling! Someone is making a lot of money out of this, but no longer from me!