The Victoria and Albert Museum Plaster Casts by the Nineteenth-Century Workshops of the Notre-Dame Cathedral: Scientific Analysis and Conservation
, Adriana Francescutto Miró 1, Sayuri Morio 2 and Charis Theodorakopoulos 3,*Round 1
Reviewer 1 Report
The article “The Victoria and Albert Museum plaster casts by the nineteenth-century workshops at the Notre-Dame Cathedral” describes the scientific analysis that allowed the characterization of the manufacturing materials and conservation treatments aimed to ensure the stability of the casts.
The article is very well written. The introduction is a delight to read and very thorough. The results are clearly explained and well described.
The reviewer suggests that this paper is accepted for publication.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
I have read the paper authored by Valentine Risdonne, et. al. dealing with the four 19th-c plaster casts of the Notre-Dame cathedral in Paris. The paper provided a condition assessment, scientific analysis, and conservation treatments of these casts. They used multiple methods for achieving these goals such as using OM, SEM-EDS, XRD, py-GC/MS, and FTIR. I find the paper suitable for publication in Heritage. However, I have some minor comments/corrections/suggestions that should be considered before publishing. My comments are as follows:
· Regarding the title, I suggest adding a subtitle to give more information about the content of the paper. Just for suggestion:
The Victoria and Albert Museum plaster casts by the nineteenth-century workshops at the Notre-Dame Cathedral: Scientific investigations and Conservation
· Please be consistent when writing the word cathedral (either Cathedral or cathedral)
· Lines 77-79: the sentence starting with <The structural issues were …..> is too long and needs to be divided into two sentences for readability.
· Line 88: for consistency, it should be Gallery 46a, not Gallery 46A
· Figure 1 should have been labeled with a, b, c, and d, the same as the other figures.
· The title of section 2.9.: I think there are repeated words in this title. Also, in the paper, the authors sometimes refer to this technique as GC/MS, py-TMAH-GC/MS, and py-GC/MS. Is there a difference between them, if not, please use only one abbreviation to avoid confusion.
· Line 198: it should be <…. for these samples ….> instead of <…. for this samples ….>. In addition, I do not know what the numbers (2) refer to in this sentence.
· Table 1: for consistency, Repro.1890-80 should be REPRO.1980-80
· Line 246: Is the date 1885 correct? It is before the date of acquiring the casts from Pouzadoux’s (i.e. 1890).
· Line 283: I think the authors meant Table A3, not Table S3.
· Line 289: To my knowledge, gypsum crystals are characterized by a needle-like shape under SEM which is already evident in the SEM images in this paper, and it will be clearer in case of larger magnifications.
· Section 3.3. The conservation treatments: If possible, it would be better to have overview images of the four casts before and after conservation to show the results of these treatments.
· Line 400: the word should be grime, not grim.
· Line 427: the word should be through, not though.
· Line 429: I think it should be <…… salts on the surface …..>, not <…… salts in the surface …..>
· Lines 454-455: it should be <…. were the main elements …..> instead of <…. were the main element …..>
· Line 461: The word should be talc and not talk.
· The conclusions are too short. They should give a bit more information about the findings of the research.
· It is better to mention Appendix B somewhere in the main text of the paper so the readers do not miss it.
· Line 612: it should be analyses and not analysis.
· Line 656: I think you should refer to table A4 in this sentence so the readers can comprehend the text better.
· I suggest adding a list of abbreviations to facilitate the readability of the paper. Because there are some abbreviations that are hard to get through the entire paper. Such as P/S and A/P rations, these abbreviations are mentioned in table A2 which are difficult to find easily.
· Lines 662-663: I cannot find Figure 4.21 and Figure 4.22.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
The article has been well constructed and the techniques applied proper. The subject is of medium interest.
However the methodology should be shown that has been used in previous works of different historical periods. The plaster analysis and provenance is a well known procedure.
Thus, I recommend in the introduction to add relevant references some of which are listed below to enrich the works done on similar analyses.
Abdullah M.A. Kame (2019) dehydration of gypsum component of plasters and stuccos in some egyptian archaeological buildings and evaluation of k2so4 activator as a consolidant SCIENTIFIC CULTURE, Vol. 5, No. 2, 49-59. DOI: 10.5281/zenodo.2649508
A. theologitis, c. kapridaki , n. kallithrakas-kontos , p. maravelaki-kalaitzaki and a. fotiou (2021) mortar and plaster analysis as a directive to the design of compatible restoration materials in frangokastello (crete) mediterranean archaeology and archaeometry vol. 21, no 1, 109-120 doi: 10.5281/zenodo.4284427
matilde quilici , charles french and petros chatzimpaloglou (2022) Torba floors from the maltese islands: a preliminary analytical study , mediterranean archaeology and archaeometry vol. 22, no 1, 183-192. doi: 10.5281/zenodo.6464964
MONA F. ALI, ABUBAKR MOUSSA AND SAFAA H. EL-SAYED (2022)analytical physicochemical survey of the recently excavated murals at the tomb of iwrakhy/hatia at saqqara, egypt scientific culture, vol. 8, no. 1, 63-79. doi: 10.5281/zenodo. 5717169
mediterranean archaeology and archaeometry vol. 21, no 3, (2021), pp. 89-122. doi: 10.5281/zenodo.5598239 chemical composition and microstructure analysis of plaster and pigments retrieved from a decorated house wall at seleucid tell iẓá¹abba (nysa-scythopolis, beth she’an, israel) dana ashkenazi, romi shnabel, achim lichtenberger and oren tal
francisco javier santos arévalo , and marisol madrid i fernández (2021) the mortars from rock-cut hydraulic structures of as-sila (sela) in southern jordan: mineralogical characterization and radiocarbon dating rocío da riva, mediterranean archaeology and archaeometry vol. 21, no 2, . 37-67 , doi: 10.5281/zenodo.4643739
roberto Giustetto, dario Gonella and eliano diana (2018) Decay of red pigments on a wall painting adorning the church of ‘san francesco dei capuccini’ in racconigi (italy): archaeometric survey and restoration intervention, in mediterranean archaeology and archaeometry, vol. 18, no 5, 65-80 doi: 10.5281/zenodo.1256055
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
General comments and suggestions
In the reported study, multiple analytical techniques were employed for the characterization of gypsum casts from two 19th C workshops. The relevance of the investigations is high as they were conducted in the context of conservation of the casts. Moreover, the association of the two workshops with the restoration work carried out earlier at Notre-Dame, makes the investigation useful and interesting. It demonstrates the importance of extant casts in museum collections as valuable repositories for reconstruction purposes when unexpected incidences occur leading to destruction of heritage objects prior to proper documentations. The comparative study of the manufacturing techniques can also result in useful insights facilitating art historical studies and well-informed conservation interventions, among others.
The documentations in the investigation are done in ordered manner with additional sources provided from data repositories. If possible, proving the spectra, chromatograms, mass spectra and X-ray diffraction patterns, acquired in the cours of the investigation, would enrich the manuscript. Despite that the data are provided, the mineralogical investigation is not covered in the text. Considering the size of the samples taken, with respect to the likely thickness of the weathering layer, the observations may not fully help to appreciate the transformations of the original plaster material. The micro- sampling is understandable considering preservation of the integrity of the heritage objects. Systematic sampling from non-weathered parts, as references, could have made the comparisons\contrasts between the weathered and non-weathered sections of the casts better.
Determinations of the compositions of the efflorescence observed on some of the casts , with some of the methods applied in the study, could be useful.
Specific comments and suggestions
Line 36: ….. highlighted as an act of preservation [4–7] since the original from which the casts were made often suffered loss of details or even destruction [3, 6-7].
Line 40: …. that can be lost without being passed to future generations.
Line: 40-42 New 3D scanning technologies are nowadays addressing this documentation needs in many cultural institutions. Moreover, historical plaster casts are extremely important as sources of documentation even for what is already lost.
Line: 55 ….. to shed light on the manufacturing techniques and conditions of the casts.
Line: 61-64 Most of the objects have always been on open display rather than in cases. They were thus exposed to pollution caused both by early heating and lighting methods within the Museum and by the general quality of London’s atmospheric air
Line: 75-77 The conservation in the Cast Courts started with the assessment of the condition of the casts. In general, the casts displayed signs of structural problems. The degradation was more evident in the form of cracking, shrinking of coatings and paint layers. (Better to use short sentence and very long ones)
Line: 84-85 ….. mould making, and allowed the investigation on the groups of casts along with their treatment [7].
Line 139: ….. from 0.63x to 4.00x.
Line 142: Samples for cross-sectional analysis: Was the resin-embedded samples polished? If so, in what manner? Line 151: ….. equipped with four objectives (magnifications of 5x, 20x, 50x and 100x), and 10x eye-
Line 151: ….. Cu X-ray source
Line 155: The mercury UV lamp is for excitation, but the observation is based on the fluorescence in the visible range of the electromagnetic spectrum.
Line 160: The data were
Line 172: Do you means range? Like 8300 to 350 cm-1? Is the model SPECTRUM 3? In what mode(s) were the measurements made? Diffuse reflectance, ATR or transmission?
Line 190: A range of methods for sample derivatizations …..
Line 193: MS Thermal programme (2) was chosen for this samples (2) …? Line 245: Said museum – The mentioned museum?
Line 259-262: …. colour patinas. Therefore, is difficult to establish whether Malzieux’s workshop did apply any patina or colour on top of the casts or if it was a homogenous finish applied to all the Architectural Association collection.
Line 264: … was visibly thicker (A) than what was observed in the ...
Line 253-255: The findings on Malzieux’s casts (Figure 3) relate to other objects acquired through the Architectural Association. They present similar surface colours and salt efflorescence.
Malzieux is mentioned in the first catalogue of the Royal Architectural Museum in ….. They can be part of the same paragraph. Check also 268-274 and, similarly, others where a sentence or two stand as paragraphs.
Line 278: All the samples analysed in this study ……
Line 294: … aluminosilicates (clay) minerals. But the aluminosilicates are few grain inclusions as shown in the elemental mapping (figure 4)
Line 299: Aluminium along with magnesium and silicon could also imply clay minerals.
Line 302: What is the grain rich in calcium? It appears superficial and not part of the cross-section preparation. In the BSE, the embedding medium appears black. Why is carbon, from this resin, not visible in the elemental mapping? How was the sample prepared? Assumed cross-section preparation that includes polishing.
Line 303-324: It would have been great to look closey the morphology of the outermost thin layers in the BSE images. The samples taken are thin in their thicknesses in the order of about micrometer (at least in one of them with the mapping given in figure 5). It is even smaller in the other case (figure 4). The gypsum cyrstals fomed could probably be associated with the effect of the exposure to the atmospheric conditions over the extended period. They could be indicators of recrytallization of gypsum and are limited mostly to the area up to a thickness of 300 micrometer. The intact parts appear to be located in the deeper part (figure 5). In the case of the thinner sample (figure 4), most of the gypsum observed could be recrytallized ones. Those not altered might not be sampled along with the weathered part. Could these recrystallizations, due to weathering processes, be some of the reasons for the flakings observed? The vacant spaces appearing as dark spots in the BSE image, in figure 5, could be remnants of air bubble formations. Could they serve as indicators of the casting process or something else? Are they noted in the intact parts of the casts far from the surface area? In how many of the samples were they observed?
Line 357: Where are these FTIR spectra? Great if they can be included in the supplemenatry material.
Line 359: The chromatograms and mass spectra acquired from Py-GC/MS could also be provided. Great that the markers data are given in A1.
Line 368-369: Regarding the simultaneous detection of sodium and chlorine in the samples, could it imply halite associated with the efflorescence observed?
Line 379: This was followed by using ….
Line 395-396: What were the components of the salt efflorescence observed? Were they characterized in the study? Great to include the information, if that was carried out.
Line 401: In REPRO.A.1916-3153, this was followed by ….. See also comments given earlier about paragraphs.
Line 431-433: The analyses were chosen to ensure the understanding of the coating materials. Priority was given to understanding the surface layers. Being the interface with the environment, this is where deterioration occurs, and conservation is needed.
Line 457-459: Could accumulation of dust on the surface be the other reason for the depositions of the aluminosilicates?
Line 460-462: See also the clay comment provided earlier.
Line 604: Great if the X-ray differaction patterns were included - where is this information used in the text, except what is mentioned in connection with gypsum.
Line 604: How about other weathering products than calcium oxalate? Few grains, per sampling spot, could also be investigated by SEM-EDS and micro-FTIR. Probably can be part of future analysis.
Line 624: Few examples of the FTIR spectra can be included here too.
Line 654: If possible, some of the chromatograms and MS spectra can be displayed in this section.
Author Response
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Author Response File: Author Response.pdf
