Ancient 'love tokens'

In the 19th century coins were often used for engraving. They are called 'Love tokens' by collectors and there is even an eBay category for collectors of such items.

Ancient coins were sometimes modified in similar ways. They seem to be very rare, I've only found a few references to them. In the academic literature I found a short piece from Schweizer Muenzblatter vol 19 1969 p. 14, “Amulettarige Uberarbeitung eines spatromischen Follis” and a three page article in English by Brooks Emmons Levy, “Another Converted Roman Coin?” (Schweizer Munzblatter vol. 32 (1982), p. 40.

The first article features a Roman follis, the second a 30mm provincial from Antioch featuring Mên.

Ken Steiglitz illustrates a Ptolemaic coin with similar modifications on his web site. I also found a Bosporan coin with similar mutilation in an old CNG catalog. The coin pictured above comes from FORVM.

I would be interested in seeing pictures of similar coins, or speculation on the why this was done. It strikes me that the few examples I've found come from very different times and places, but have similar grooves. This could be because grooves are the easiest thing to cut, so everyone who mutilates a coin naturally does grooves.

FORVM attributed my coin as being from the Amphipolis mint. I don't know much about Alexander bronzes, does anyone know if this is correct? What is the diagnostic?

Peter Rosa on YouTube

Someone has made an animated slide show of Greek Coin replica dies made by Peter Rosa. The video is set to some classical music that I don't recognize.



There is also a Part 2.

bkrpr.org

The Book Ripper Project, bkrpr.org, has plans and software for a book scanner that costs $250 to build. With a human turning the pages it can scan 600 pages an hour.



The $250 cost is mostly two digital cameras, which you can also use for anything else you want.

(via TeleRead)

Paul-Francis Jacquier catalog 36 up

Paul-Francis Jacquier's catalog 36 (Summer 2009) is up. The sale features 775 (+79) lots of ancient coins and 380 lots of numismatic literature.

Looks like some good stuff. Lot 1043 is Price's The Coinage in the Name of Alexander the Great and Philip Arrhidaeus estimated at 225 euros.

I haven't bought coins from Mr. Jacquier but I have bought numismatic books and had no problems.

Network of scientific numismatic libraries to form

Founding Meeting in Glasgow
A new international network of scientific numismatic libraries is about to be establishing the International Numismatic Libraries Network (INLN). Its aims will be to coordinate common efforts (for ex. in developing cataloguing standards) and quite generally to distribute and to exchange informations.

The INLN includes already 25 numismatic libraries world-wide and will be founded formally at the International Numismatic Congress in Glasgow (2nd and 3rd September 2009).

For more informations, please contact Ans ter Woerds (Geldmuseum, Utrecht) or Elizabeth Hahn (American Numismatic Society, New York).

(via International Numismatic e-News (July 2009) [PDF] via the ANS Twitter feed)

I wasn't aware of International Numismatic e-News. It seems to be monthly and in English and German. The current issue (link above) previews the XIVth International Numismatic Congress in Glasgow and lists newly published numismatic books. The main web site, muenzgeschichte.ch, seems to be German-only and I couldn't figure out if other issues of International Numismatic e-News are available. I did find an interesting German numismatic blog, http://numismatica.twoday.net/. Read it in English using Google's translator.

Cory Doctorow essay on public organizations shaking down the public for access to their own collection

Cory Doctorow's essay, “UK National Portrait Gallery threatens Wikipedia over scans of its public domain art” is featured on bOING bOING today.

... If you take public money to buy art, you should make that art available to the public using the best, most efficient means possible. If you believe the public wants to subsidize the creation of commercial art-books, then get out of the art-gallery business, start a publisher and hit the government up for some free tax-money.

acsearch.info

Simon Wieland, Lars Rutten and Markus Beyeler launched acsearch.info today. It includes 300,000 ancient coin auction and sale records with photos.

The announcement says that the site had planned to launch later in the year, but “hurried a bit” to launch this week.

I wish them the best of luck! The site is visually pleasing. Unlike CoinArchives, if there are more than 1000 results it is possible to view them all. Unfortunately, acsearch.info only shows 20 coins per pages meaning a lot of clicking and scrolling when dealing with large query responses.

Lars and Simon's previous site was romanatic.com. It will be interesting to see if they have any kind of cross-linking planned for the two sites. Currently Romanatic lets users search WildWinds and CoinArchives, and I'd expect an acsearch.info link can't be far away. It will be more interesting to see if they can come up with a way to automatically generate links from acsearch.info results to scholarly information on Romanatic.

CoinArchives.com to become a pay site

The great research tool, CoinArchives.com has removed 93% of it's content. A new pay site, CoinArchives Pro, will offer the old content. The new site has a $600/year subscription fee.

$600/year is a lot to host other peoples images and offer text searching over other people's text. I hope that the new venture is so successful that it inspires many imitators to offer better content at lower prices. (Meaning I lack the ability to explain to my wife where $600 goes every year, but maybe someone else will sell me access to old catalogs for $30/year).

CoinArchives Pro access might be worth this kind of money. We are talking 750,000 coin records. Compare to a full set of BMC Greek that costs $3000 and has only about 30,000 coins. I'm not saying CoinArchives Pro isn't worth $6000 for a decade of access, just that it will be tight budget-wise for me to find the money.

I wonder if the glossy catalog dealers, who produce catalogs at a loss for their customers, will see a jump in subscriptions because of this move?

ISEGRIM back

ISEGRIM is back at a new location, http://isegrim.dasr.de/isegrim/anmelden.html.

For those who have never seen it, ISEGRIM is a complicated search engine over ancient coins from Asia Minor in the world's collections. It has no pictures. It can be cryptic to use because of it's 1980s-style text-based query language that uses German abbreviations. FORVM user Archivum has written a user's guide. The format is similar to Otfried von Vacano's Typenkatalog der antiken Münzen Kleinasiens (1986).

(via FORVM)

Laurens van der Maaten's automatic recognition of coins

RJO and Peter Tompa wrote to let me know about a press release, Computer Recognizes Archaeological Material And Fake Van Goghs by NWO (Netherlands Organization for Scientific Research).

The press release discusses the PhD thesis of computer vision researcher Laurens van der Maaten. Via Google, I learned that last week van der Maaten defended his PhD thesis Feature Extraction from Visual Data in conjunction with a symposium on 'dimensionality reduction'.

His personal web site allows download of Matlab extensions that implement his techniques and a technical report on how to use it.

I wrote to Dr. van der Maaten who provided me with an paper, “A New System for the Classification of Modern and Historical Coins”. The historical coin portion of the paper discusses an experiment using 4822 Merovingen coins from the Dutch Money and Bank Museum (AKA The Netherlands Mint Museum or Het Nederlands Muntmuseum.) The researchers (van der Maaten, Paul Boon, and Eric Postma) trained their computer using the Merovingen coins and then fed 50 different Merovingen coins into the system. The goal was to find coins “perceptually similar” in the training database. The image above is taken from that paper (and modified by me to show a single row of pairs.)

So, rather than trying to identify the ruler or inscription, the task was to find coins that looked similar in the opinion of 10 non-numismatist humans. The paper reports that the computer got 20% right "magnitude", 43% right "orientation". I think orientation was figuring out how to orient the coin (right-side-up) but I am not certain.

The research was supported by NOW/CATCH, a Netherlands program to develop innovative tools for accessing cultural heritage.

In a personal email, Dr. van der Maaten reported that in a database of 4000 Roman coins the computer got a good match for 50% of the queries. I assume the criterion are similar, a match that looks perceptually similar to non-numismatists, such as a similar imperial portrait facing in the same direction. The Roman database used in the experiments is online, RICH: Reading Images for the Cultural Heritage. (I was previously unaware of this database and encourage Roman coin collectors to try it out and send me their thoughts in the collection, and its presentation and web interface.)

A success rate of 20% to 50% doesn't sound great but it is pretty impressive! As with the COINS results discussed on this blog, I am curious to see if statistical problems boosted the success rate. Most Roman coins feature a man's head facing right on their obverses. A system that classified EVERY image as a man facing right might be rated as 25% success by non-experts. I look forward to the publication of the Roman results in detail.

An image and 38 second video of the Roman coin recognition can be seen here. It is either a silent movie or my PC doesn't have the right version of Quicktime to play the sound.

Greek and Roman Coins from the du Chastel Collection

I recently won a copy of Greek and Roman Coins from the du Chastel Collection (Callataÿ & Heesch, Spink: London, 1999). Originally published at £60.00, it's now remaindered for £20 (about $33) from Spink. I got mine on eBay from Charles Davis who still starts auctions below wholesale.

It's a well-researched and well-made catalog of mostly Greek coins. The 41 plates are great. The 819 coins, collected by count du Chastel are all exceptional. Unfortunately in numismatic publishing, mere quality does not translate into sales. It's hard to compete with free color dealer catalogs. The best book in a category, such as Roman Republican Coinage (still in print at $490!) or Roman Provincial Coinage can move copies at high prices, while the second-best book doesn't move at all unless heavily discounted.

du Chastel is great but it's best feature is the superb dust jacket. The dust jacket photograph, by Stephen Sack, is the best I've ever seen on a coin catalog. It's an extreme closeup of the reverse of a sestertius of Nero, featuring the emperor on horseback. Sack manages to get an 8” picture out of the center of a 35mm coin that looks like an artistic masterpiece of detail and patina and light.



The image isn't photoshopped. My understanding is that he spent months looking at hundreds of worn bronzes with interesting patinas under a microscope looking for the textures and images that eventually make it into his work.

Sack had a show of his fine-art coin photography at the British Museum. The catalog, Metal Mirror: Coin Photographs by Stephen Sack is mind-blowing. Although I missed the London premiere I saw the pieces at Ariel Meyerowitz Gallery in New York. Very impressive.

I believe the Ariel Meyerowitz Gallery is gone but a few of Sacks' coin works can are available on VCoins, like this peacock and this goddess.

I can't afford a €4,000.00 picture of a peacock no matter how much I might want it, though. I bought a second copy of the catalog intending to dismember it and mount several images in 8x10 frames. I couldn't bring myself to take the blade to the duplicate catalog, though!

Robotic coin dealers coming to Europe?

James Wilson's strangely-titled report, “Germans taste machines with Midas touch” for the Financial Times says

... Germans will soon be able to sate their appetite for the yellow metal as easily as buying a chocolate bar after plans were announced on Tuesday to install gold vending machines in airports and railway stations across the country.

...

A prototype vending machine on display in Frankfurt Airport on Tuesday appeared to be a converted version of the dispensers typically used to sell snacks. For €30 airport shoppers could buy a 1g wafer of gold, with a larger 10g bar priced on Tuesday at €245 and gold coins also on sale.

...

When the Financial Times bought the cheapest product it was dispensed in an oblong metal box labelled “My Golden Treasure”, with a certificate of authenticity signed by Mr. Geissler but no receipt and the wrong change. Mr. Geissler said he hoped to have a more advanced prototype available this month.

...

Numismata graeca: Greek coin-types, classified for immediate identification

Leo Anson's 1910-1916 work, Numismata graeca: Greek coin-types, classified for immediate identification, is now available from archive.org.

This book attempts to publish a catalog of all Greek coins ordered by types. This makes it a useful work for identifying coins of unknown cities, especially those lacking inscriptions. 150 plates!

The work is similar to Richard Plant's Greek Coin Types and their Identification but it uses photos rather than drawings, doesn't illustrate all types, and doesn't index animal or god types.

Fakes of US coins getting better?

F. Michael Fazzari, “Chinese Fakes Get Harder to Spot Over Time”:

...

Today, excellent copies of U.S. Trade dollars and Flowing Hair dollars have been reported. From what I have seen, a "second generation" of these fakes is very deceptive.

While most Chinese counterfeits, such as the Morgan dollar illustrated here, will not pass inspection by a knowledgeable numismatist, those fakes often do. This is especially true when their surfaces are chemically altered or cleaned to simulate age.

...

Software from COINS

I've written before about The COINS Project (Combat On-Line Illegal Numismatic Sales), a European Union sponsored effort “to enable the traceability of cultural heritage objects”. The project is developing “technologies aimed at allowing permanent identification and traceability of coins”.

COINS recently released software that attempts to compare and match coin photos against databases of coin photos. The newly released software comes in several pieces.

The key pieces are the Image Recognition Tool, said to be able to match a photograph against a database of coins, and the Shape Matching Package, which is apparently also for matching photos.

There is also a a web spider “to discover and identify stolen coins illegally sold on the internet” based on the open-source search engine Nutch. The spider comes with source code. It should robotically download all image files on a site and compare them against the database of coins. (My first reading of the search code did not impress me. I found code that looks for pages containing the word 'coin' or 'moneta' but I didn't find code to invoke image processing.) There is a user interface, which can be previewed here, for conducting simple searches of a coin database. For example, enter 'Alexander' in the simple query box, or 'eagle' in the iconographic query box. This Flash-based web interface is nothing special, and the spider's ability to search for stolen coins is only as effective as the photo-matching capabilities powering it.

A good image recognizer for ancient coins would be quite useful. It probably wouldn't help much to find particular categories of cultural property, such as ancient Cypriot and Chinese coins, as these are usually sold with descriptive text making photo recognition superfluous. Recognition technology would be useful to detectives for particular stolen coins and for computer-assisted die studies by numismatists.

I downloaded COINS' Image Recognition Tool (IRT) and loaded it with a database of 80 fake coins from my own photo-file. Although the IRT can compare images in popular formats such as JPEG the database only accepts greyscale TIFF files. I used Pierre Gougelet's free XnView to convert color JPEG files to greyscale TIFF.

I queried IRT using a fake image that wasn't in the database. I chose a cast fake Himera bronze, a type which gets past many dealers despite having been published as false in Wayne Sayles' Classical Deception. I had several of fakes from the same forger's mold in my database. The software coughed up five possible matches, with the highest being another coin of this type! (The other offered matches made little sense and were ranked poorly by the software.)

That seems like impressive performance. However, my database is small. Only 43 coins, or about half of the 80 coin database, correctly segmented as round. The other half of samples weren't exacted from the patterned background. Backgrounds that a human wouldn't even see, such as a finger, are not detected as expected by IRT.



The 4 non-zero matches returned in my first try represent 10% of the 43 coins whose edges were detected. Obviously a matcher that thinks 10% of the database matches a particular specimen is not yet trustworthy enough to assist law enforcement. Furthermore, the coin I first checked is a cast fake, so the geometry of the edge should help the software to detect matches more easily.

Oddly, the edge geometry didn't play a role. Although the correct match was found, the system believed a 60 degree rotation was needed. Actually the coins had the same orientation! (The picture at the top of this post is of this match.)

I tried genuine coins of different types than the fakes and got many false positives. The strength of the match is reported by IRT in the 'Matches' field. The two identical casts got 17 matches; a Ptolemaic bronze got 8 matches a shipping envelop with an eBay logo. I don't know what number is considered by the COINS scientists to be a good match.


I've just started playing with this software. I will try the Shape Matching Package next and report here on its accuracy. I invite other collectors experimenting with this software leave a comment on this post describing your success or failure matching coins using COINS' tools.

Ron Landis' Athenian dekadrachm

American engraver Ron Landis is well known in hobo nickel circles but his replicas of ancient coins have attracted little attention. I could not find his Athenian dekadrachm replica in Fischer-Bossert's The Athenian Decadrachm.

Landis engraved dies for Athenian dekadrachms, tetradrachms, and didrachms. According to Dr. Lawrence J. Lee World Coins & Medals, Landis' company Gallery Mint Museum minted quantities “in the upper hundreds” (I believe in 2000). In 2007 Lee's company restruck “no more than 100 of any denomination”.

The Gallery Mint Museum closed in 2005. Photos of Landis and the manufacturing equipment can be seen at Arkansas Road Stories.

At least one “dekadrachm” was struck in gold, weighing 3.4 troy oz (or 106g!)

Ron Landis apparently described his engraving technique in “Hand engraving and die sinking”, published by the ANS in Coinage of the Americas Conference: The medal in America (vol. 2, 1997). (Has anyone seen this? I do not have a copy.)



UPDATE: Dr. Wolfgang Fischer-Bossert wrote to remind us that his book does not include fantasies that are neither dangerous nor meant to deceive.

BMC Arabia

George Hill's BMC Arabia, the Arabian Greek coins in the British Museum collection, has been scanned and is available for download from the Internet Archive (formerly the Million Book Project).

(via Digital Library NUMIS)

I'm surprised they put this up; George Hill died 60 years ago and thus his works are not public domain in the UK, and since the book was never published in the USA the law binds servers here to UK rules.

Antique coin forger sentenced to six months jail

The London Metropolitan Police report that David Hutchings, 43, unemployed of Cross Street, Nuneaton, Warwickshire, plead guilty at Warwick Crown Court on March 16, 2009.

... Hutchings claimed to be an avid metal detectorist who had found the coins at various times and locations....

Hutchings' defence throughout police interviews and at court, was that he bought the coins from two dealers 'Gary and Steve' believing they were all genuine. However, he was unable to identify either dealers whereabouts.

Also found at Hutchings' home address during the search were a number of real coins, believed to have been used as a base for test striking during the manufacture of some of the fake coins.

Experts from the British Museum and Fitzwilliam Museum assessed the coins recovered as part of this case and concluded that all had either been manufactured by casting in a mould or struck using forged dies.

Detective Constable Ian Lawson from the Met's Art & Antiques Unit said: "Whilst the overall value of these coins is relatively low, the level of deception and harm Hutchings has caused the individuals and businesses embroiled in his lies is significant.

(Via a post by Dave Welsh on Unidroit-L and Ancientartifacts.)

Found in the crop of a chicken

John Hooker posted on Moneta-L the story of a Celtic coin found in the crop of a chicken.

(The crop is a pouch in a bird's neck that temporarily stores food.)

The chicken came from Iceni territory, but the coin is Catuvellauni perhaps it ate the coin while visiting a poultry show in Hertfordshire?

Artifact forgery

An article by John Timmer on Ars Techica discusses the recent article, Forging Ahead, by Charles Stanish in Archaeology.

Charles Stanish writes

In an antiquities store in La Paz, I recently saw about four shelves of supposed Tiwanaku (ca. A.D. 400-1000) pottery. I told the owner that most were fakes and she became irritated and called me a liar. So I simply touched one at a time, saying "fake," "real," "real from Tiwanaku," "fake," "fake made by Eugenio in Fuerabamba," and so forth. She paused for a moment, pulled one down that I said was real, and told me that it was also a fake. I congratulated her on the fact that her fakes were getting better and she just smiled. My mistake is an instance of what San Francisco State University archaeologist Karen Olsen Bruhns has identified as a very real problem—the experts who study the objects are sometimes being trained on fakes. As a result, they may authenticate pieces that are not real.

The article mostly discusses South American antiquities. There is nothing about coins.