uguntde

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Posts posted by uguntde

  1. A very beautiful one piece back, with two pins at the bottom. Long slim f-holes which could be French. Ribs cut too short,filled in with ebony, almost unfigured. Very difficult to identify.

    Could we see the epurfling in the corners? Where is the purfling joined together? How are the f-holes cut? Were the plate corners rounded after or before they were glued?

     

  2. 8 hours ago, Jeff Jetson said:

    Thank you Uguntde,

     

    I wanted to know because I buy the Brilliants on sale and save a lot of money that way, the Ambers never seem to be on sale for me to try them. The Brilliants seem to have much higher tension than the Karneols.

    Somewhat higher for violins: http://www.warchal.com/tension_chart_violin.html

    For viola they report them all as the same: http://www.warchal.com/tension_chart_viola.html

     

  3. On 12/02/2017 at 2:40 PM, Jeff Jetson said:

    Any opinions on the difference between Warchal Brilliants compared to the Amber line?

    I tried the two on the viola and they are very similar, but different to the Karneol, the latter is somewhat softer in tone. They all have the same string tension. Between Brilliant and Amber I find not much difference. They are both good strings.

    Same for Amber vs Karneol on the violin where I haven't tried Brilliant. The Amber is excellent. I personally prefer their timbre to Evah-s, you get more warmth in the tone. I also find the Evah-s are very poignant in the beginning, but mellow down soon, ending up closer to Dominants. The Warchals change a little in the first few days and then maintain their timbre for a long time.

  4. 5 hours ago, Ratcliffiddles said:

    I use optical, microscopic measurements, and both photographic and scans (ordinary high res. flat bed scanners equipped with CCD sensor). As was the case regarding the answer for the slanted grain, the differences in year-to-year ring variations are negligible in a piece cut near radially. Think about it.

    I don't understand your question or maybe my explanation wasn't clear.  Yes I do take measurements at several levels, but that is beside the point. I only do that in order to level out the natural, generally insignificant discrepancies within the same piece.  I end up, after combining contemporaneous year-ring data, with a mean series. Pearson's r is then calculated between each two sets of data, one being the mean series and the other every separate data-set in the database. The subsequent t-values  are derived from each r obtained in relation to the overlapping number of rings between sample and reference (or number of degrees of freedom).

     

     

    I use reference data from Europe, but also contained in the database are US, Russian and other geographical data, including the Himalayas, but I am yet to match up anything to this last one.

    But in direct answer to your question, if I were only to use European geographical data, and the violin was made with wood (unbeknownst to me) originating from the USA, or China, I would not expect to see anything significant, or convincing with Master references from the Alps, and I would probably not be able to date it.  What I may find, however, are direct, highly significant correlations with data from other American or Chinese instruments that may be in my database, which, even if undated, may be of interest. 

    Whilst I don't have many American fiddles in my database, I have a fair number of Chinese ones.  You never know... 

    You answered my point well, you take measurements at several levels along the grain. I assume your optical software pull out distances between grain lines that you then correlate with the reference data, or is the correlation done on original scans or pictures?

    I assume there is no reginoal data with Europe?

    Do you use any oft the publicly available softwares availabe or linked on
    http://web.utk.edu/~grissino/software.htm

    What I wondered was whether you use databases for different regions in Europe, for example The International Tree-Ring Data Bank seems to have regionally differentiated maps.

     

     

     

     

  5. On 09/02/2017 at 0:47 PM, Ratcliffiddles said:

    I will try to address some of the questions.

     

     

    As far as the question about a possible slant, off the quarter piece. This is not unusual although the slant, is rarely significant in my experience.  I have tested  series, taking measurements at a perfect quarter, and the same at a 10 degree slant. The difference in the results are insignificant.  This is due to the fact that dendrochronology is based on the relative variation from one ring to the next, and to the next etc..and the differences between these yearly variations are totally negligible.

     

     

    It is true that knowing what goes on behind the statis is important. Essentially the process calculates the product-moment correlation coefficient (Pearsons' r), after the data have been normalized, followed by a t-test, (Student's), to evaluate the significance of this correlation.  The particular algorithm I tend to use was devised by Baillie & Pilcher (1973) and is used in several dendrochronological software packages.  It is not perfect, and there are some specific instances, visually identifiable whilst measuring the rings, where this specific algorithm is unsuitable. 

     

     

    Insofar as Sospiri's affirmation about the longevity of Alpine Spruce as a tree, it appears totally unfounded and not supported by the research done by serious people. Yes trees exceeding 350 years do exist, although they are rare. 

     

     

    People who practise violin dendrochronology do use reference in the public domain, many of which are published by the International-Tree-Ring Data-Bank.  (ITRDB).  In addition we create our own proprietary reference from series recovered from instruments.  These often contain more accurate "signal" than published data (although correlating with them), as the quality of the timber is generally better than the one contained in randomly selected trees used in the compiling of Master references.  When I say "better", I mean that soundboard wood tends to be without distortion that may have been caused by branches, or other growth disturbances for whatever cause. 

    The compiling of instrument reference chronologies, made up of well correlated data from instruments can be invaluable to date a sample series. Personally I have several 100s of these chronologies, some from instrument data demonstrating highly significant inter-correlations, and which often happen to be from a similar origin.  These can reasonably be described as being representative of specific groups of instruments.  In particular, instruments made in Italy in the 1720 to 1780 period,  others, representative of the Dutch/English instruments made in the 1650 to 1720  period, yet another representative of the French instruments made in the 1730 to 1790 period. 

    Other instrument references are compiled with well correlated data from instruments made in a variety of countries.  When an instrument is tested and results demonstrate highly significant correlations with contemporary instruments, but made in several different countries, we can safely conclude that the wood from a specific geographical origin was traded and exported to these other locations.  This is often the case when 19th century instruments are concerned.  Often, ring data from many of these will correlate significantly with both one or more Master reference from Germany, as well as data from 100s of instruments made in Germany, France, Bohemia, England and Italy. In such cases, no suggestions as to a possible provenance of an instrument can realistically be made based on the dendrochronological results.

     

     

    I will point out that there are still many series from instruments that I am unable to date.  Why? primarily because I cannot identify significant enough correlations, replicating at the same date. Why do I not see them? because, they are not there to be seen, meaning that my database does not "recognize" the particular subsequent ring variations within the sample.  Any pressure from the commissioner to "find" a date, believe me, would be ignored.

    In some cases, the statistics can point to 2 different dates, meaning that significant correlations are identified with several datasets, suggesting a different temporal placing. When such cases arise, often the graphical comparisons of the plotted data will clearly favour one date. When they do not, a process of analysis of different parts of the sample data is carried out.  This segmentation analysis will tests consecutive or overlapping segments of the sample data, and look for consistency of dating between them.  This powerful operation either confirms one date, or neither.

     

     

    As far as I (and others who perform dendro on instruments) the more data is collected the better and the more conclusive the results are likely to be.  This is why I (we) have been able to identify these batches of wood used in specific places at a specific period.

     

     

    When a test works, yes, it is a  "method to assist in the attribution of violin".

    Assist just means may contains information, derived from the cross-dating, which over and above the dates of the wood. That information could be one of the examples of coincidences that I mentioned in my previous post.

     

     

    It is not up to me to say an instrument is definitely French or Dutch, or Italian, or of a particular period.  I may suggest, however, based on the results, a likely provenance for an instrument, if that information is tangible.  If not, meaning that no explicit group or "batch" of instrument has been identified as significant cross-matches, as is often the case as well, I will just say so.

     

     

    People incessantly point out that a dendro date of f.e. 1675 does not mean any more than that, that an instrument could have been made at any time after this date, and could indeed have been made last week. True of course.

     

     

    What if, a violin is made nowadays with old reclaimed wood, from a tree which happen to have grown in one of the areas specifically geographically related to one of the "batches" aforementioned?

    Yes? what if... as Jeffrey and others have mentioned, the "decider" is not the person doing the dendro. The expert will, based on their knowledge and experience, decide whether the dendro results are useful or not.  Nobody is forcing them to take the results into consideration, to include them in their final assessment, or to make them public, and can ignore them too if they wish (or at their peril...).

     

     

    Here is an example of the above. I find that many instruments from the Bisiach workshop in Milan from around 1900 and also well after, often come up with dendrochronological dates of between 1660 and about 1730. In addition to the date, the cross-matching tests also expose 100s of significant direct correlations with wood "typically" used in Italy in the 18th century, by makers from Venice in the North to Rome and Naples in the South.  So how to interpret these results? Did Bisiach get hold of a large old stock from previous generations of makers? are the violins by Bisiach? are they mint condition Stradivari disguised as late 19th century violins?

    I can only report what I see in my results.  Thankfully, I have had access to 100s of samples of un-worked timber from their workshop, which have proven useful in that respect. 

    I will point out that I also have a fair idea about instruments besides dendro, as I am (was) a violin maker and repairer, and was, until dendro took over, working professionally as such since 1983.

    BTW.I have just tested a violin with two apparent same tree matches with two separate Stradivari. Am now waiting for an answer to my query which was "1717 Stradivari?" I'll report later..

     

     

     

     

     

    For dendrochronological assessments, do you take photographs of the front of a violin or do you somehow scan the surface of the wood. How do you correct for the curvature arising from the arching, in particular for instruments with a high arching?

     I assume you use different locations on the plate for statistics - otherwise I can't imagine how you would do a t-test.

    Also, don't you use reference data for different regions of Europe, and with this make an assumption of where the instrument (or its wood) comes from?

     

  6. 1 hour ago, fiddlecollector said:

    resinates.JPG

    resinate fe.JPG

    I don't think 3 carboxylic acids will yield a stable octagonal iron complex, the oxygens are too close. There is probably no proof for a rosinate metal ion coordination complex. In other words this is just the stoichiometric figure for some kind of a salt. 

  7. 6 hours ago, Don Noon said:

    I had assumed that the KOH was neutralized by the acids in the rosin.  There is always a small amount of rosin extra, undissolved, which I thought was done to make sure all of the KOH was used.

    You may be right, this was Michelman's idea, as rosin is mainly abietic acid. But considering that this is probably a very weak acid one may need a large excess of KOH. Michelman reports that he needs an 'acid number' of 160 to 170, I assume he refers to the excess of KOH needed. Fe(III) in FeCl3 is already Fe(H2O)6Cl3, a relatively stable complex, which is probably perfectly happy at high pH. Too much heating would convert this into ferric oxides which might precipitate. An iron(III) complex with abietic acid itself is unlikely, as it would not act as a complex or chelating agent. This might change if the double bond was hydrated, but this requires a metal catalyst, usually Pd (unlikely Fe would do the job). It would be worthwhile to dertermine the state of iron in these varnishes.

     

  8. 15 hours ago, Michael Appleman said:

    Good evening fellow violin-obsessed people. I picked up this fiddle a little while ago thinking it might be good player for a student or one of my adult amateur friends, and just got around to putting it into playing shape. I plan to replace the finger board and bush the peg holes before setting it up. It's otherwise in solid shape, having been professionally repaired on the inside as far as the cracks are concerned. It may have been a training exercise or just been sitting around in a pro shop for years before finding its way to an auction. I figured it is probably a ca.1800 Mittenwald and haven't been too curious to find out more, but as I started in on it today I noticed the blacks of the purfling seem to be whalebone. Not the thick plastic looking stuff one sees on a Jacobs, but a kind of black I remember seeing on an "old Fussen" of the double-purfled "pseudo Mariani" type I had many years ago. The blacks are relatively thin, but are a deep glossy black that isn't faded anywhere, and where the surrounding wood has worn away or shrunk, the purfling blacks stand proud of the surface. I'm not used to seeing this sort of purfling on Mittenwald violins, but I'm not an authority on these nor other German language sphere violins, so I'd be very glad to get some input from those MNers who are familiar with this sort of violin and may have seen this sort of detail. Thanks in advance!

     

    c18mitttop.jpg

    c18mittback.jpg

    c18mittscroll.jpg

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    c18mittbackpurf1.jpg

    c18mittbackpurf2.jpg

    Isn't this shape of scroll and the purfling quite typical for Jacbos? AN example of Jacobs work althou in b/w is found here:

    http://www.thestrad.com/gallery/from-the-archive-a-violin-by-hendrik-jacobs-1704-4/

     

     

  9. On 01/02/2017 at 2:52 PM, Don Noon said:

    Rosin, dissolved with water and potassium hydroxide, precipitated with iron chloride.  That's it, no madder or anything else.

     

    Hopefully the dried version of the color will be stable.  My walnut oil version doesn't appear to have changed over 2 years, so that's encouraging.

    So your rosinate part is at very high pH. The iron chloride was probably yellow, and turned into a nice red brown in solution with the rosin at high pH. I assume you never neutralised the potassium hydroxide.

    I assume that Fe(III) probably undergoes a complexation with the rosin and such complexes are very stable. Michelman showed by simple stoichiometric analysis that such complexes are formed. Their stability may be pH dependent. If this was the case you would see a change by adding some acid to neutralise the potassium hydroxide.

    I wonder whether the high pH varnish causes any problems for the wood. I though Michelman somehow neutralised the rosinate at some stage.

     

  10. 2 hours ago, jacobsaunders said:

    One should realise that Chas. & Sam. Thompson were a Music shop/Music Publishers, and that the violins would have been made by outworkers. Indeed one can (rarely) see a pencil signiture of the actual maker inside the belly. The quality varies, yours being quite a refined nice one. Up untill now, I have never seen one with a date on the label like yours. Also I cannot quite see from your pics if the neck is nailed on, or not (would surprise me) although I have seen plenty with worm damage, they seem to have tasted nice.

     

    I share your like of these old cheaper English violins. At the start of the 19th C there was the Continental Blockade for about a generation, and the English continued to make their own „cheap“ fiddles for themselves. Once this blocade finished, the dealers started to import much cheaper from Mittenwald and Markneukirchen, and the cheaper end of english making was dead as a dodo overnight (don’t tell Mr. Trump!)

    The neck is nailed, yes. And the ribs that are one piece from C-bouts corner to C-bouts corner.
    Very nice work.

    The finger board was previously raised, and is now being replaced after a neck graft.

     

     

     

    2017-01-21 15.45.26.jpg

  11. Sychamore is just the English common name for maple. I have seen sychamore trees next to each other in England, one showing ripples, the next one not. This makes me think it is not a genetic feature. There is plenty of nice sychamore in England now. I see lots every time I walk through Green Park in London, all  nicely figured as you can see from the ripples in the bark. The park web site however claims they are Acer saccharinum and they are not up for grabs.

     

  12. I am getting increasingly interested in 17th and 18th century English violins. Some instruments of Duke have a fabulous sound and are built like Amatis. He seems to have influenced others.

    Here is a London violin which is possibly what the label says, Charles and Samuel Thompson. It is reminiscent of Duke, although somewhat more tardy. Tarisio tells us that they sold on the work by other makers http://tarisio.com/cozio-archive/browse-the-archive/makers/maker/?Maker_ID=748.

    This one has some unfortunate and awful repairs to the scroll, probably after worm damage. Interesting features are  a nice one piece front and back, one piece top and bottom ribs, interestingly chamfered linings, probably the original pegs, nice purfling and edgework.

    Do you think this fiddle is what it says it is? After it has been repaired, what do you think the value of such an instrument should be?

     

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  13. On 11/01/2017 at 8:55 PM, Rue said:

    Lol...I could have checked!

    Our city is getting a new art gallery. It is also over budget and the opening kerps getting delayed. But it is peanuts compared to this concert hall!

     

    An €800million concert hall will certainly be a driver for culture in Germany and beyond - well exemplified by the opening concert which included an Uraufführung by a piece by Wolfgang Rihm. Their first concert season is already sold out. Simon Rattle is trying to convince Britain to invest on a similar level in London, interesting to read the Guardian article with respect to this https://www.theguardian.com/music/2017/jan/12/why-germany-is-proud-of-hamburg-elbphilharmonie-and-why-britain-should-care-about-that

     

  14. 5 hours ago, lorenzo pedersano said:

    Martin is 100% correct. The signature is laughable.  This seller needs to put much more effort into faking the signature. It wouldn't fool anyone that has seen a few Collin Mezin's. This is just another in a very long list of fake Ebay instruments.  ViolinsRus, If you think that a seller of Cellos and violins in France is going to sell French instruments worth tens of thousands of dollars for a few hundred dollars. the only thing that I can tell you is to go ahead and buy some. That will teach you a very valuable lesson. When you lose a lot of money, I think that the lesson will be very well learned.  Those of us in the trade used to call buying something like this , "Paying for your Education".

    The signature is not bad, although not perfect. This is what it is to be. I have two 1888 at the moment. No cello though.

     

     

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  15. 21 hours ago, martin swan said:

    Additional arguments would be the model, the varnish everywhere, the edgework, the bizarre reeding on the front, the scroll eyes ... and the fact that it's brand new

    This is a new instrument with a bit of dirty antique-ing, and the seller is a renowned faker who pretends on one Ebay ID not to know if something is genuine or not while offering certificates on another Ebay ID.

    And btw the signature is fake and the inking on the scroll chamfers is very messy!

     

     

     

    21 hours ago, martin swan said:

    Additional arguments would be the model, the varnish everywhere, the edgework, the bizarre reeding on the front, the scroll eyes ... and the fact that it's brand new

    This is a new instrument with a bit of dirty antique-ing, and the seller is a renowned faker who pretends on one Ebay ID not to know if something is genuine or not while offering certificates on another Ebay ID.

    And btw the signature is fake and the inking on the scroll chamfers is very messy!

     

     

    The maker is an excellent copyist, you need to give him credit fir this. Whoever gets this cello for below £2000 got an amazing deal if it sounds. If I was a maker, I would copy those, the Hels and the like, and not the Strads. I would certainly not put in new Chinese pegs to spoil it all in the end. It almost seems intentional.

     

     

  16. I, too, felt things would do well in London owing to the weak pound. That worked to my advantage when I bought a fabulous violin case in the last Tarisio London auction. The case is historically important and wouldn't have even made the modest reserve if I hadn't bid so I don't know what the dealers and collectors are looking for.

     

    I don't usually sell anything which is why I'm not familiar with the costs involved in unsold items. I'm a collector by instinct and habit so I was just testing the water but the water turned out to be very chilly and unwelcoming, not the warm experience I was hoping for.

     

    Glenn

     

    I don't know what your instruments were. However, there were many instruments that were not set up for playing, and set the case some were yours, it is generally a good idea to ensure they are strung up with a half way decent bridge and the sound post set.  If they are not in playing condition you loose half the market, that is enthusiastic players and those few dealers who can actually play and make a judgement on sound. In this respect

     

    Bongartz always did a better job in fitting instruments up - making the 20% charge somewhat more reasonable (if he doesn't charge extra for this service). One could well argue that the auction houses could do a much better job than showing the same stuff from auction to auction, by commissioning a violin maker to set up instruments, by working on better options to return instruments, by providing essential information upfront.

     

    Nobody prevents anyone from starting yet another violin trading organisation. I often thought whether this would work, especially as the 20% charge seems quite high. Once you have the amount of staff that Brompton and Tarisio have and you pay your rents, insurance fees etc you will probably end up with similar figures if you want to make a profit.