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  • How'd they do it??

    there is so much speculation as to how the Greeks were able to engrave hardened dies both in terms of technology and physical ability (eye-sight on those semi-hemi quadrahemi whatever fractions)
    Lenses? hereditary engravers guild of myopics? gem dust and tiny drills and scrapers?

    Any ideas?

    Tom

  • #2
    Although I imagine that they could have used crystal for lenses, my bet is on the naked eye. (And as you suggest, nearsightedness was probably a factor in being selected to cut the fractional dies.)

    Here in San Antonio we have a young lad who writes short poems on grains of rice without benefit of magnification. He probably won't be able to do that for many years, but did the ancients live long enough to have their vision degrade?

    Bill

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    • #3
      I have often wondered if the magnifying properties of water was used as a "lens" whe cutting these small dies used to strike the very smallest denominational silver fractions. If a shallow glass vessel was filled with water it would refract light to offer a huge amount of magnification in direct sunlight...just a thought!

      Marc
      www.ancientimports.com

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      • #4
        Water is a very interesting idea. I'm just not sure how practical it would be for die engraving. How would someone hold a glass container of water low enough that it could give suitable magnification, but high enough that the container wouldn't get in the way of the engraver and his tools? Also, how close does a glass of water need to be to an object for its magnification properties to work?

        Just some questions. I don't know the answers off hand.


        Oliver D. Hoover

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        • #5
          Hi Oliver,

          This would be a great experiment...wish I had some time to work on it! My thought has always been, in theory, that if you sat at the right angle looking down and through a glass jar containing water that you could then use it's magnification and be working on the coin on the other side...you would see the tool clearly as you worked and yet it would offer different amounts of magnification depending on the angle used. I guess a tall cylindrical glass vile would offer the most magnification if looked through as say a 45 degree angle from top to bottom.

          Marc
          www.ancientimports.com

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          • #6
            Hi Marc,

            I just tested the theory at dinnertime. It looks like one could conceiveably use a container of water for magnification the way you suggest. There is some slight distortion using a standard glass of water, but this could probably be corrected by using a larger container.

            I wonder how ancient glass stacks up to modern glass for clarity. I've only ever seen it with heavy patination from spending centuries in the ground. This usually makes it quite beautiful to look at, but you certainly can't see through it.

            Oliver D. Hoover

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            • #7
              crystal

              There have been many lenses found in archaeological digs. Usually they end up being described as "fire starters". Lucian described the giant lens used by archimedes to burn Roman ships in the siege of Syracuse.
              Here's an excerpt from an article in the London Sunday Times:

              "Robert Temple, a professor of the history and philosophy of science at Louisville University, Kentucky, said his research suggested Archimedes's success meant he was the father of modern laser weapons such as guided bombs and missiles.

              Temple has retranslated texts detailing the optical skills of ancient civilisations. In The Crystal Sun, published this month, he gives new descriptions of how Archimedes used mirrors on the Romans.

              The oldest of these texts, by a historian named Lucian and a medical writer called Galen, are from the second century AD, more than 300 years after the siege, but references in them show they are drawing on works written soon after it.

              Temple believes these scholars had read the now-lost works of Polybius, a Greek historian and contemporary of Archimedes, whose surviving descriptions of Rome's rise to world dominance are among the most respected of their time.

              For Temple, the clinching evidence comes from experiments recreating Archimedes's feat. The first was in 6th century Constantinople when the Byzantine capital was besieged by enemy ships until it employed dozens of men holding mirrors to set fire to them.

              Modern scientists have recreated such events under controlled conditions. In 1973 a Greek scientist, Ioannis Sakas, decided to see whether "burning mirrors" could set fire to a boat.

              He lined up 60 sailors on a quay with large mirrors, from which they reflected light onto a small boat about 50m away. The boat was in flames within three minutes.

              Paul Ewart, an Oxford University professor of physics and a specialist in optics, said Archimedes would have been unable to make his mirrors flat enough with the available technology.

              However, curators at the British Museum recently relabelled a glass fragment excavated from the ancient Assyrian city of Kalhu after realising that what they had considered to be a bauble was likely a finely ground lens for correcting short sight. It was made about 800BC, about 600 years before Archimedes was born. - London Sunday Times"

              Marvin Tameanko relates how two of the most interesting finds of polished quartz crystal were in a) Pompeii in the house of a gem engraver and b) in Egypt in the house of an artist.

              They were probably far more sophisticated than we presently are aware.

              Tom

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              • #8
                Lenses in antiquity

                A few years ago I wrote an article for the Celator concerning the use of lenses in antiquity, with emphasis on their possible use as an aid in engraving coin dies and gems.

                Hundreds of ancient lenses exist. Unfortunately, they are usually listed as bangles or jewelry pieces by museums.

                My conclusion was: it is very probable that most coin and gem engravers in ancient times used magnifing lenses. Certainly, some of them used lenses as several lenses have been found in shops of artists (Pompeii, for one).

                I could probably find my entire article if someone was interested.

                Bart Lewis

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                • #9
                  Everyone seems to think about glass mirrors, true they would be more efficient, but what about polished metal surfaces [polished shields ?] ? They may not be as efficient, but put up 100 or more instead of 60 and you would still have a lot of concentrated energy.
                  Back to the original start, several others have posted articles about the use of ptics in the ancient world. as has been pointed out, much has been mis-catalogued as baubles, ornament or just ordinary glass ware.

                  Bruce
                  Last edited by bruce61813; Jan 15, 2004, 10:42 AM.
                  Too many coins - not enough time

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                  • #10
                    lenses/camera obscura

                    I am glad Bart found the article and that it is now posted as an "article" on ancients.info. I see where a lot of talking points for discussions on Moneta-L came from.
                    On a related point, the book "Secret Knowledge" by Hockney points to the use of lenses and the camera obscura by painters of the renaissance -
                    http://www.snarkout.org/archives/2004/01/21/
                    There are some remarkable parallels between what seems to have been going on then (e.g. secrecy, an abrupt transition into super realism, the resurgence of all things classical including coin minting).
                    The camera obscura poses some interesting possiblilites related to calendars and religion. It is the same concept as a pinhole camera. We know of all these ancient monuments aligned to the rising or setting sun on a specific day. The sun low on the horizon may have served another purpose. A piece of hide with a small hole stretched across two of the stones of Stonehenge would project a rather clear image of who or what was on the outside into the circle (The first movie theater!?). The sun low to the horizon would provide sufficient background lighting to cause this effect.
                    It is reasonable to conclude that the camera obscura effect would have been noticed by the ancients. Some bright young person may have figured out how the process works. The same is true of light refraction which every fisherman is acquainted with. I imagine polished quartz crystal was highly prized both as an item of curiousity and probably as toys for the kids. Someone must have been curious enough to research these further and refine them to the point of producing usable lenses.

                    Tom

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