1) Carol Mattusch: „…Müller from Faunhofer Institute in Fürth, which normally analyzes industrial products, tested the metal…“
Harald Müller: Müller is not from Fraunhofer Institute in Fürth. Fraunhofer Institute is one of his cooperation partners, where he uses a high energy computer tomograph for his investigations. Müller (IMS Institute for Materials Science and Authenticity Testing GmbH, Wiesbaden) himself is a materials scientist dealing with scientific investigations of historical artifacts and cultural heritages, and he has more than 17 years of experience. He has a special expertise with metals, particularly of copper alloys (brass, bronze).

2) Carol Mattusch: „Müller concludes that the head could not have been produced before the second century C.E. (142) but cites no data to support that conclusion.”
Harald Müller: I disagree with this comment because I wrote: “The high lead and the low tin content makes it unlikely that such an alloy was produced before the 2nd century, illustrated in the following diagrams 1 and 2.“ The diagrams show data of accurately dated bronze portraits (G. Lahusen, E. Formigli) and strongly support my conclusions.

3) Carol Mattusch: “He (Müller) speculates that “the head … was produced more recently, very likely manufactured by using ancient material” (146), but scrap metal was a common ingredient of statuary bronze, as mentioned by Pliny the Elder (HN 34.98).“
Harald Müller: It is well known that scrap metal was partially used by the Romans as an ingredient of cast alloys, and it was mentioned in Müller’s discussion of the investigated alloy: “The existing zinc found its way into the alloy either through the ore used or by an addition of brass.” But what do Carol Mattusch’s comment mean? Scrap metal can only suggest an earlier date an alloy was produced, i.e. the addition of scrap metal to an alloy can simulate an older age of the material, not a younger.

4) Carol Mattusch: „Müller’s hypothesis that ancient coins might be used to cast a modern forgery aired in a television interview with Sönje Storm (“The Mystery Conman,” Deutsche Welle, Feb. 2016)“
Harald Müller: The filmmaker in her documentary elaborates on the question whether forgers might use melted coins“ (Timecode 0:34:20 – 0:34:40“ in: “Fakes in the art world – The mystery conman“, DW Documentary, https://www.youtube.com/watch?v=1lNSXB4i4fE&list=PLovlAKbQVz6A6aeBgS_E6WONvnSIG6LAc&index=9). I, never speculated whether the used material was made from ancient coins: My answer: “We believe because of a range of material characteristics that correspond with antiquity that this sculpture was made of genuine ancient material. There is ancient material available for things like this and it would not be an entirely new idea to use or to have used old material for forgeries.”

5) Carol Mattusch: „The captions to his (Müller’s) illustrations raise more questions than they answer, and the images from computer tomography (fig. 12) do not show the round chaplet holes that he reports (146).“
Harald Müller: I, respectfully, disagree with this comment. The captions of his illustrations are very clear and informative, and figure 12 shows the three perpendicular computer tomographic cross sections through a hole of the investigated bronze portrait, and clearly display a round hole produced by the removal of a round chaplet (arrows).

6) Carol Mattusch: “… metallurgical analyses done in 2012 by the Paz Laboratorien für Archäometrie (93–105), which suggest that the heads (two female bronzes in Basel) are Roman.”
Harald Müller would like to rectify: Paz did not write that his results suggested the authenticity of the two female portraits to be Roman. For one of the female bronzes he wrote exactly: “The results do not contradict the assumption that the bronze is Roman”, but the results (only some measurements at the surface of the object using a handheld x-ray fluorescence spectrometer) are very lean. For the other bronze Paz wrote: “The results do not contradict the assumption that the bronze is Roman. Rather, based on material composition and source of the used materials (lead) conclusions led be drawn, which support the authenticity and the assumed age of the object “Roman Goddess”. But his results (some measurements at the surface of the object with a handheld x-ray fluorescence spectrometer, one single elemental analysis of the alloy composition using mass spectrometry and lead isotope analysis) are still too lean for a real prove of the authenticity of metal objects.

I thank the author for the critical comments. But overall, I would like to have much more carefulness and fairness in such a review.

Harald Müller
IMS Institute for Materials Science and Authenticity Testing GmbH
harald.mueller@ims-analytics.de