In that lot I purchased for $5.20 a coin were the 2 that I posted yesterday and here is this bowl shaped Christ coin. The notes are difficult to read but it looks like: Byzantine Manuel I 1143-1180 Billon aspired Trachy Obv. Christ enthroned facing forward Rev. Manuel holding crosses BMC 52 R2137 S1963
I posted a really nice one yesterday. This is my second bowl shaped coin. I have 4 coins of Isaac II to go through and post. If I’m not mistaken, Isaac was the ruler after Manuel.
Per: Dumbarton Oaks “Byzantine Coinage”, 1999, Second Edition... it seems that "trachy" is the more commonly accepted term for bronze, billon, and electrum cup-shaped/concave coinage: "Scyphate" seems to be the term for gold or silver cup-shaped/concave coinage. https://en.wikipedia.org/wiki/Scyphate But... I only have a few of each, so I am not an expert. :-o
Got a bowl shaped coin, not a trachy, not a scyphate, just a very common Galerius – Concordia Militvm AE, which I think is a Radiate fraction. It just startled me that it is bowl shaped, $ 15 - so I bought it: 16.5 x 15.4 mm, 2.340 g Mysia, Cyzicus 295-299 AD struck under the authority of Diocletian RIC VI Cyzicus 19B Ob.: GAL VAL MAXIMIANVS NOB CAES radiate, draped and cuirassed bust of Galerius right Rv.: CONCORDIA MILITVM emperor standing in military dress at left, facing r., receiving victory from Jupiter, holding scepter. K and officina letter A in lower center. and here, from the side.No idea if it was struck in this shape or someone just bended it:
Well….. Now I have to know. I own a handful of Byzantine Follis, but do not have any of the cup shape trachy’s….. Always been afraid of looking like a coin rookie so I never asked…. But why the cup shape? It certainly couldn’t have been easier to strike in that shape and I cannot imagine they would have gone to such trouble without a practical purpose…… Is there a reason that these were struck in a cup shape?
The real question is, why adopt the dished design anyway? One thing, and really one thing only is sure about this, which is that it was not an easy thing to do. In the first place, the designs on the dies with which the blank coins were struck were carved in such a way as to keep the design correctly proportioned: it looks straight even though it’s bent, something that becomes very evident when you try to photograph them in such a way that they face you but are still clearly concave. Scanning is better for this because the fall of light emphasizes shadow, but with adequate lighting the concavity is quite often visually undetectable in conventional photography. So that was cunning artistry, and not least because the dies themselves, we are fairly sure, were made curved, rather than deforming flat coins by striking them. In fact, it seems likely that the flat blanks were first struck with blank dies to curve them, and then the resulting curved blanks were struck with two obverse dies, one for each side of the coin’s design, to ensure a good impression all over the coin’s surface. This means that the manufacturers were readier to triple the production process complexity than to make dies that fitted each other snugly, apparently, but we can mainly take from this: there must have been a point to all this, but what? The concavity may make the coins harder to bend, but it makes them far more prone to cracking, because the edges come out so thin, as you see below. And once a coin is cracked, it’s actually in much more danger of snapping. They just don’t stack, seriously. Actually a silly explanation. The manufacture was not regular enough to guarantee anything but the most basic fit. quoted from: https://tenthmedieval.wordpress.com/2015/07/20/a-problem-of-concavity/ The problem with trachys was producing two dies with the exact same curve shape. If the obverse was more convex than the reverse was concave, the center of the design would be poorly transferred. If the obverse was less convex than the reverse was concave, the centers cold be clear but the edges would be weak. In order to produce a well struck scyphate it is necessary that both obverse and reverse dies have the same radius of curvature in order to match exactly. Quoted from https://community.vcoins.com/celator-vol-12-no-06/
Why the cup or bowl shape? I don’t know if it’s true or not but I have been told that bit was designed that way to make it easier to lift the coin off of a flat surface.
