Arthur Herbert Church FRS and the Palace of Westminster frescoes

Frederick Kurzer


In a long and distinguished career, A. H. Church FRS, professor of chemistry successively at the Royal Agricultural College in Cirencester and the Royal Academy of Arts in London, contributed original work to a wide range of chemical topics. As a talented painter he became an expert in the chemistry of paints and painting and was the obvious person, in 1894, to be entrusted with the conservation of the important frescoes in the Palace of Westminster, which had deteriorated with the passage of time and suffered severely in the unfavourable atmospheric conditions of Victorian London. Church identified airborne sulphuric acid as the chief destructive agent, and succeeded in halting further decay of the murals by judicious procedures, some of them of his own devising, and ensured at a critical juncture the eventual survival of these threatened art treasures. Church's 12 years’ activities in this area, being published exclusively as Parliamentary Papers, remained largely unknown except to the officials and Commissions directly concerned with the problem, but as a significant achievement in his life's work they merit due attention and credit.


When in 1834 the old Palace of Westminster was destroyed by fire, Parliament lost its home, which it had occupied for centuries. The opportunity was seized to replace the conglomerate of ancient piles, barely fit for their late function, with a building that would in scale and dignity symbolize its pivotal place in the body politic. The New Palace rose magnificently on the banks of the Thames over a period of 15 years (ca. 1837–52), after Barry's1 celebrated plan. At a very early stage, consideration was given to its future internal embellishment by sculptures, paintings, mosaic and carving. The proposals included schemes intended to give an impetus to a revival of the art of historical painting in general, and of fresco painting in particular, the latter having been lying dormant in England for some time.2 It was thought that large murals depicting historical and religious subjects would provide a background particularly appropriate to the spacious apartments and galleries of the great building.3

The plans were set in motion by the appointment of a Royal Fine Arts Commission under the presidency of the Prince Consort, which for the next 21 years directed and superintended the artistic operations. Its membership included the Prime Minister, Sir Robert Peel, senior politicians, and prominent men of letters, with the architect, C. Barry, in attendance. Its permanent secretary was C. Eastlake,4 an eminent figure in the art world, who also undertook the onerous duty of recording its acts in detailed Reports, published as official Parliamentary Papers.5 The debate concerning the preferred methods of accomplishing the great plan, and the selection of the subjects to be depicted, was protracted and wide-ranging, referring to the artistic no less than the moral, spiritual and religious implications, and indeed the political resonances. Critical analyses of the history and voluminous records of the Fine Arts Commission have been given by Boase (1954)6 and by Clare Willsdon in her comprehensive work (2000) on British mural painting.7 The latter highlights Prince Albert's close participation in its work, and in his particular championship of the fresco as the preferred form for the mural decoration of the Palace;8 his influence prevailed, but the choice proved unfortunate, as will become apparent.

In accordance with its remit, the Commission invited in 1840 proposals from artists in the form of cartoons ‘not less than 10 and not more than 15ft in their largest dimension, illustrating subjects from British history’. An exhibition of the resulting 140 entries was held in 1843 in Westminster Hall; it was inaugurated by The Queen, and aroused lively public interest, attracting some 1800 visitors each day (figure 1).9

Figure 1

Exhibition of the cartoons in Westminster Hall. From Illustrated London News, vol. 3, p. 17 (1843). (See note 9.)

In the meantime, the Commission endeavoured to gather reliable information about the current state of fresco painting, and the technical background of its methods. Extensive surveys were presented by C. H. Wilson,10 the director of the Government School of Design, and by Eastlake, and formed substantial parts o£ the Commission's Reports. P. Cornelius,11 the acknowledged master in the field, was invited to travel to London in 1841 to advise on the proposed fresco work, and Sir Robert Peel urged Eastlake to find out all he could from him about ‘the mysteries of this art’. In response to an inquiry by Eastlake, Michael Faraday performed some tests on specimens of lime and commented on their fitness for the plaster base in fresco painting.12

The favourable preliminary responses to its technical enquiries persuaded the Commission to call for the submission of finished specimen frescoes. The promising standard of the entries encouraged it to initiate the first phase of the scheme, and to appoint six artists to undertake the work. These were W. Dyce (who was specially recommended by Cornelius), G. W. Cope, D. Maclise, J. R. Herbert, J. C. Horsley and E. M. Ward.13 Although relatively young men, they had already acquired a recognized reputation, but with the exception of Dyce they were as yet not familiar with fresco work. Three of them (Dyce, Cope and Maclise) visited Continental studios to study ongoing work before addressing their task in Westminster. After much delay, operations began (1845) in the Lords’ Debating Chamber with Dyce's large panel in pure fresco depicting ‘The Baptism of King Ethelred’.

By 1847, the Commissioners had decided the details of their grand scheme for the mural decoration of the Palace:14 it was to consist of several cycles of frescoes, to be sited in the suite of spacious halls, galleries and corridors that form the central ‘spine’ of the network of the Palace's wings. This innermost tract comprises, from south to north, the Royal Robing Room, the Royal Gallery, the Lords’ Chamber, the Peers’ Corridor, and beyond the Central Octagonal Hall, the Corridor and Chamber of the Commons. St Stephen's Hall and the Waiting Halls extend laterally on either side of the Central Hall (figure 2).

Figure 2

Plan of the Palace of Westminster, showing the central position of the apartments containing the murals. From (Anon.), The new Palace of Westminster, 7th edn (printed by permission of the Lord Great Chamberlain; Warmington & Son, London, 1852).

The Commission's original plan was not strictly adhered to, nor was it completed in its entirety.15 The required expenditure had to be voted upon and authorized annually,16 and the enterprise was not free from criticism, both inside and outside Parliament. In one of the early debates, for example, the Member for Middlesex (Mr Osborne Bernal) warned the House that ‘whenever a Commission was appointed of gentlemen of great taste, they might depend that the public purse was in great danger.17 Unexpected technical crises and embarrassments of the Commission were a welcome opportunity for the exercise of satirical comment by the magazine Punch. Certain serious disappointments notwithstanding, the Palace of Westminster became, in its peculiar way, a significant centre for the pioneering experiment of the study and practice of fresco painting and for a revival—albeit abortive—of historical painting in mid-nineteenth-century England.

Although the artistic merit of the frescoes satisfied contemporary taste, their defective keeping qualities proved disappointing, and their more or less rapid deterioration in the London atmosphere gave cause for concern. Various empirical measures for their conservation failed to provide permanent remedies. When in 1894 signs of renewed damage were noticed, the First Commissioner of HM Works, H. J. Gladstone, consulted the President of the Royal Academy of Arts, and was referred to its professor of chemistry, A. H. Church FRS, as the best qualified person to assess the situation and provide expert advice.

A. H. Church FRS and the chemistry of painting

Arthur Herbert Church was born in London on 2 June 1834 and educated at King's College School, where his early inclination towards science as well as a decided talent for drawing and painting received the first encouragement. He next spent four years (1851–55) at the recently founded Royal College of Chemistry in Oxford Street. A fellow student working at the adjacent bench was W. H. Perkins, with whom Church published his first scientific paper;18 he was presently selected by Professor A. W. Hofmann, the Director of the college, as a research assistant. There followed four years spent in Oxford, where he gained a first-class honours BA degree in the Natural Science School (1859). Returning to London, he established a private laboratory and engaged in chemical consulting and tutorial work. During this early phase of his career, Church demonstrated his talents as a landscape painter; he first exhibited in the Summer Exhibition of the Royal Academy in May 1854 and continued to do so, and even to sell some of his paintings at this and other venues.

From 1863 to 1879, Church was Professor of Chemistry at the Royal Agricultural College, Cirencester. Here his wide interests found full scope in a wide variety of original researches, ranging from agricultural problems to the determination of the composition of minerals, and the chemical and physical characterization of gem stones, glasses and porcelain. Scientific investigations into archaeological questions were inspired by his connection as Honorary Curator of the Cirencester Museum of Roman Antiquities. His many researches of this period may be exemplified by his isolation of the copper-containing iridescent pigment Turacin19 (later identified as a porphyrin derivative) from the plumage of certain species of birds, and his characterization of a previously undescribed mineral from Cornwall as a complex cerium phosphate, apparently the only cerium mineral found in the British Isles, and later named churchite in his honour.20

In 1879, Church moved to the Royal Academy of Arts as its first professor of chemistry. The new affiliation focused his attention on the nature and function of materials used in the art of painting, pottery and glazing. He published in 1890 his accumulated knowledge, much of it the fruit of his own researches, in his treatise The chemistry of paints and painting,21 which in its successive editions remained for many years the standard text in its field and was translated into German by the eminent physical chemist Wilhelm Ostwald.22 Church's high standing and reputation were recognized by his election to the Fellowship of the Royal Society in 1888. He retired from the Academy in 1911 and died in his house near Kew Gardens on 31 May 1915, in his 81st year23 (figure 3).

Figure 3

Sir Arthur Herbert Church FRS. From A. H. Church, Records and recollections. (See note 23.)

Before describing Church's restoration work at the Palace of Westminster, it is expedient to give a short account of the chemical aspects of fresco painting and of the problems that arise in the conservation of its productions.

Chemistry of fresco painting

In the simplest form of this technique (fresco buono), the picture is painted on the surface of a freshly laid layer of mortar (scheme 1) that is still wet.24,25

The white plaster consists of slaked lime intimately mixed with fine white sand; the preferred source of the lime is specially selected pure marble (calcium carbonate, I) which is successively converted by strong heat into quicklime (calcium oxide, II), and by reaction with water into ‘slaked’ lime (calcium hydroxide, III). To fit it for use in fresco work, it must be ‘aged’ by extended storage, ensuring its smoother putty-like consistency, probably by changes in its physical microstructure. Two or more layers of this mortar are laid down, the outermost made from the finest sand to produce a smooth flat surface. Faulty preparation of the ground jeopardizes the whole work; unsuspected impurities in the sand (such as traces of iron) may produce unsightly efflorescences or stains that appear only years later and are almost impossible to eradicate because they pervade the very fabric of the affected area.

On this still wet ground, the artist traces the design from his cartoon and paints the picture, using a limited palette of alkali-fast pigments, suspended in pure water or limewater. Only as much ground is prepared as can be painted swiftly in one session. Successive areas of ground are thus prepared and painted until the composition is complete. The pigments penetrate some way into the plaster; the resulting subtle effect, together with the absence of glare on the matt surface, gives the classical fresco its particular transparency and charm.

After the artist's work has been done, a further essential chemical change occurs: atmospheric carbon dioxide slowly converts a thin surface layer of the mural into the carbonate (III→IV), which, forming a compact water-insoluble solid coating, protects the picture from further change and damage. This is the case in clean atmospheres and dry climates; exquisite murals have survived in a clean and bright state under favourable conditions since antiquity.

Chemistry of fresco decay

The situation is very different, however, when frescoes are exposed to the corroding action of the urban atmosphere carrying soot, tar, dust, ashes and acid-laden moisture. As Church never tired of emphasizing, the most serious threat is posed by sulphuric acid, borne invisibly by minute vapour droplets that penetrate the very interior of buildings. The source of this acid is the sulphurous contaminant of coal, which is burnt in large towns as domestic fuel and in factories. In Victorian London, coal consumption was prodigious, producing correspondingly large quantities of sulphuric acid. According to a contemporary estimate, between half a million and one million tons of acid were annually discharged into the air of the metropolis.26

In the combustion of coal, the sulphur impurities (usually taking the form of iron pyrites inclusions) burn to sulphur dioxide, which is in turn converted by air oxidation and hydration into sulphuric acid. The acidic mist settling on the fresco attacks its protective carbonate layer and penetrates the plaster (namely calcium hydroxide) below it, converting both into gypsum (calcium sulphate; IV→V and III→V). This is somewhat soluble in water and is therefore subject to loss by slow dissolution; moreover, its formation from the hydroxide involves a small net increase in volume, setting up a slow internal expansion and disintegration process.

Stereochrome frescoes

The obvious difficulties of traditional fresco painting, and the uncertain durability of its productions, encouraged efforts to vary and improve the available techniques. In a successful modification, the use of waterglass, pioneered by J. N. Fuchs (1825) and developed by A. Keim, introduced advantages in both the execution and the permanence of the work.27 It was promoted in England by the Prince Consort and was adopted with advantage in several instances by the Westminster artists. Here the image is painted on the dry plaster ground in water-colour (instead of the pigment suspension), enabling the artist to produce more deliberate and detailed work. The finished mural is ‘fixed’ by being sprayed with a waterglass solution (sodium or preferably potassium silicate).28 This penetrates some way into the surface and leaves, on drying, a tough protective layer.29 The chemical reactions between the plaster, silicate and pigments are undoubtedly complex processes, possibly involving polymerization processes.

Church's conservation work

The apparently relentless deterioration of the Westminster frescoes resulted from two main causes. An immediate factor had been the lack of mature experience in this medium of the originally commissioned artists who, with the exception of Dyce and Maclise, had had to acquire the special skills as their work progressed. The importance of the meticulous preparation of the plaster ground, and the correct mounting of the panels to avoid the effect of damp,30 was possibly not fully understood, or such precepts were occasionally neglected. This proved particularly disastrous in the case of eight frescoes painted (1848–54) in the Upper Waiting (‘Poets’) Hall, which had in a sense functioned as a place of trial where the six artists employed in the project might experiment and perfect their powers.31 The murals soon deteriorated: their surface blistered, the pigments changed colour and the underlying plaster began to disintegrate.32 Even Maclise's vast murals in the Royal Gallery, painted in waterglass at a later date (1859–65) (see p. 9), began to fade before his eyes, as his work slowly progressed.33

Apart from these inherent pitfalls, the corrosive London atmosphere exerted its insidious destructive effect on all frescoes of the Palace, as it penetrated every part of the building.34 In 1862 a Select Committee investigating this continuing decay recognized and pronounced the incompatibility of the traditional fresco with the London atmosphere. The dedicated efforts of Cope, Dyce and Horsley to retouch and repair from time to time their own and other artists’ work afforded no permanent solution.35 With the death of Prince Albert (1861), and the winding up of the Fine Arts Commission (1864), the grand scheme came to a halt and was not again taken up, although in a different form, until many years had passed.

In the absence, at that time, of recognized institutions devoted to the conservation of works of art, advice was sought from various quarters, notably in 1872, from the eminent scientists Sir Frederick Abel FRS36 and Dr John Percy FRS.37 However, being experts in the field of explosives and metallurgy, respectively, they confined themselves to recommending a careful superficial dusting, and rinsing with water;38 they were sufficiently aware of the difficulties to suggest that future commissions should preferably be performed in waterglass fresco.

When, 22 years later, Church was entrusted with the care of the frescoes, he was by his expertise in the chemistry of painting materials and by his artistic insight better placed than most before him to deal with the complex problems. He had, moreover, already gained relevant experience by his supervision of the restoration of G. F. Watt's large mural in the Hall of Lincoln's Inn (1890). For the next 12 years he directed and personally participated in the patient work of cleaning, restoring and conserving these important artistic treasures.

He recorded his activities in the unusual form of Memoranda addressed to the First Commissioner of HM Works, which were published among the official Parliamentary Papers.39–42 They described his careful assessment of the problem, the experiments and practical trials, and the adoption of the most appropriate and least invasive measures (figure 4). He gradually attended to nearly all the murals in the principal apartments of the Palace, from the Royal Robing Room to the Commons’ Corridor (see p. 5), starting his operations on the two frescoes in the Royal Gallery. This initial painstaking work provided the pattern for his later operations.

Figure 4

Title page of Church's Memorandum on the Murals in the Palace of Westminster. (See note 39.)

The Royal Gallery is dominated by Maclise's43 two vast murals: the first, ‘The meeting of Wellington and Blücher at Waterloo’, and measuring 45 feet by 12 feet, was painted in stereochrome between 1859 and 1863; its companion on the opposite wall, ‘The death of Nelson’, was completed two years later44 (figure 5). Church found the frescoes structurally sound but in a deplorably dirty and neglected condition. They were covered with a grey saline film consisting, according to his analysis, of the sulphates of calcium, potassium, sodium and ammonium, darkened by an admixture of soot, tar and dust. Beneath this deposit the pigments were still firmly held. Careful trials in an inconspicuous corner of the painting showed that it was safe to detach most of the soot and dirt by gentle ‘flicking’ with soft cotton dusters. The mineral incrustation yielded to sponging with distilled water, continued until the wrung-out water from the sponges, at first inky-black and depositing a thick black sediment, was clear and nearly colourless.

Figure 5

Daniel Maclise, ‘Meeting of Wellington and Blücher at Waterloo’, detail of cartoon (1843). (© Royal Academy of Arts, London.)

The procedure left the murals in a reasonably clean and bright condition,45 but it was clearly desirable to confer some permanence on the improvement. A paraffin coating of the frescoes would consolidate their surface and isolate it from further attack by the acid humidity. Initially, Church was reluctant to adopt this approach, because a coating, however subtle and transparent, would impair the intrinsic ‘matt’ non-reflecting character of the true fresco and was liable to complicate future conservation measures. On balance, he eventually decided in favour of the coating, but delayed applying it for three years until he was satisfied that the cleaning had not impaired the stability of the fresco ground and that no appreciable further efflorescences had appeared.

Church introduced a significant improvement into the coating regime by his preferential use of ceresine, the hardest and highest-melting available paraffin (obtained from the naturally occurring organic mineral ozokerite), which produced a correspondingly tougher skin. It was applied during the warm dry summer season (1897) as a solution in toluene; this treatment became a regular part of the standard preservation procedure.46 It conferred a chemically inert and durable protective coating, and strengthened decaying areas of the plaster by penetrating some way into the fabric. It also mitigated optically the obscuring effect of the grey mineral film that could not be removed mechanically without causing further damage. All these advantages had to be balanced against the realization that with each paraffin treatment the murals lost some of their true fresco character, as Church himself clearly pointed out:The frescoes in the Royal Robing Room are no longer frescoes. While retaining the aspects of frescoes, they have been transformed gradually into paintings which have had their original binding material replaced mainly by ceresin and paraffin wax, unalterable compounds capable to resist even sulphuric acid.47

Church next dealt with the murals in the Royal and the Peers’ Robing Rooms,48 involving five large true frescoes painted by W. Dyce49 in the 1850s,50 and a sixth work by R. Herbert.51 They had already been the object of restoration and overpainting by C. W. Cope52 but were now in a precarious state. They were covered by the usual grime, and disfigured by brown patches, but more seriously they had locally suffered actual structural decay by sulphation of the underlying plaster, and loss of pigment. After a very delicate preliminary cleaning, the decayed areas were expertly reconstituted with fresh plaster, sparingly repainted in tempera, and their surface finally consolidated with ceresin.

In the following autumn (1895) work centred on the murals in the Lords’ Chamber, which had in fact been the first to be commissioned. The largest, completed by W. Dyce in 1846, covers an area of 11 feet by 20 feet above the Throne. Five smaller panels on historical and allegorical themes were the work of Maclise, Cope and J. C. Horsley,53 executed at about the same time (1847–49). Although they had been restored by the original artists (1873), they were now so obscured by soot and dirt as to be barely distinguishable and had lost some of their plaster ground.54 Church restored them to a satisfactory condition and was confident that ‘when the House was lighted up with electricity, so that the frescoes can really be seen, they will once more take their proper place in the decorative scheme of the Chamber’.

Not all the frescoes could be saved: Church found the panels in the Upper Waiting Hall in an advanced state of decay, and no serious attempt at restoration could be contemplated.55 Only one of them (J. Tenniel's St Cecilia) responded partly to the treatment.56

The conservation work involved a great deal of sheer labour, which had nevertheless to be performed with the greatest care and delicacy, requiring the help of craftsmen of unusual skill and integrity. Church was fortunate in securing the service of two highly competent operatives (Messrs Redhead and Drinkwater), who were seconded from the specialist firm Shrigley & Hunt, of Lancaster and London. Redhead had been associated with Church in the restoration of the Lincoln's Inn frescoes in 1890, and continued as his trusted assistant throughout the Westminster project.57 Church acknowledged in each of his Memoranda the support he had enjoyed from his associates, who had performed his instructions with scrupulous care to his full satisfaction.

During the next 10 years Church continued to monitor the murals closely. Apart from paraffining Maclise's monumental works (1897), and incidental repairs conducted by Church personally, no major work was undertaken until 1905,58 when the remaining two groups of eight frescoes of more recent vintage lining the Peers’ and Commons’ Corridors were restored.59 They had been covered for many years by tightly fitting sheets of plate glass but had nevertheless deteriorated by acid dampness entering from the rear. Their plaster had in some places been softened by sulphation, some pigmentation was lost and their surface was disfigured by dark stains and the usual grey bloom. Their restoration, which had been delayed by the difficulty of removing and replacing the protective glazing, was eventually accomplished. By now, Church had gained confidence to intensify the paraffining process by using a more concentrated ceresin preparation of the consistency of a cream, which was spread over the surface and driven into the plaster by heat from a spirit flame or smokeless gas jet.

For the future care of the frescoes Church recommended a routine of regular dusting by a clean air blast, washing with distilled water and renewal of the ceresin coating at intervals of three or four years. He stressed the importance of maintaining the environment at an even temperature, high enough to prevent the deposition of the acid mist on walls and murals, and suggested improvements in the ventilation. Given such care, the existing murals could probably be preserved indefinitely. Nevertheless, he considered it inadvisable to add pure or stereochrome frescoes to the collection, concluding his eighth and last Memorandum with the caution thatthe increased and increasing consumption of coal in London, and the greater licence allowed to the Gas Companies in the matter of freeing their gas from sulphur compounds must result in a serious augmentation of sulphuric acid in the air of the Metropolis. It is this acid, which constitutes the chief destructive agency at work on pictorial and other artistic productions.60

Although the Commissioners of Works acknowledged the gravity of the warning,61 there was no prospect of any amelioration of the situation at a time when some 5 miles of new streets were added annually to the metropolitan area, with corresponding further increases in smoke and pollution. Church deplored particularly a relaxation of restrictions imposed on the London Gas Companies relating to the sulphur content of the gas they supplied; it had effectively quadrupled the emission of sulphuric acid from this source (from 11.5 to 43 grains per 100 cubic feet of gas).62 The Companies did their best to play down these charges,63 but Church's views were corroborated by Professor T. E. Thorpe FRS,64 who affirmed, in his evidence to a Select Parliamentary Committee, that the construction of additional coal-burning electrical generating stations in London's residential areas (some of them planned near museums, galleries and Royal parks) would have a damaging effect on buildings, works of art and even the plant life of the open spaces.65

Later developments

The protection of wall paintings by a water-repellent surface, advocated by Church and endorsed by Laurie,66 his successor at the Royal Academy, was taken up widely by conservators. It found particular favour in connection with the English cathedral and church restoration movement of the late nineteenth and early twentieth centuries, when it became general practice to seal dilapidated or newly uncovered murals in this manner.67 Although safeguarding the front surface, it unfortunately did not protect the underlying ground against moisture diffusing from the rear, from damp walls. Unable to penetrate the imperviable wax layer, the accumulating moisture disrupted the plaster, eventually lifting and detaching the paint. A further drawback of the sealing process was its virtual irreversibility, prejudicing subsequent remedial measures, even though the removal of wax coatings by the application of solvents has eventually met with some success.68 By the 1950s, wax sealing was thoroughly discredited and severely discouraged.69

The decay of London stone

Church's work on the Westminster frescoes was complemented by his investigations of the decay of urban building stone, marble and mortar, which confirmed his identification of the destructive effect of sulphuric acid on both. In its attack on stonework, the acid humidity slowly converts the calcium carbonate of Portland stone into calcium sulphate (gypsum). Unlike the insoluble native carbonate, this is slightly water-soluble and is gradually leached from the stone by gypsum-bearing drips. As they evaporate on the surface, they deposit a growing crust of this mineral, together with carried-down grains of sand, the whole blackened with soot and dust. The resulting incrustations, accumulating under cornices, projections and ledges, may reach a depth of several inches, while the original stone is correspondingly depleted and weakened.70

In this case, however, Church was able to apply an effective remedy based on a simple chemical reaction, namely the conversion in situ of the soluble gypsum into insoluble barium sulphate. In this process, the affected porous stone is treated with a saturated aqueous solution of barium hydroxide (equivalent to ca. 3% BaO), so as to penetrate as far as possible into its interior. Here it reacts with calcium sulphate (gypsum, the product of the harmful sulphation stage) and is deposited as the water-insoluble barium sulphate;71 the equivalent of calcium hydroxide that is liberated turns slowly into insoluble calcium carbonate (that is, the substance of the original stone). The net effect is the displacement of the gypsum by firm compact water-insoluble barium mineral filling the interstices within the structure of the stone, thus reconstituting and strengthening its fabric. Further attack by sulphuric acid is neutralized by remaining concentrations of the baryta, which is renewed by occasional fresh application as required.72

The method proved of utmost value and effectiveness in conserving decaying urban stonework, both in general building practice and particularly in saving important architectural features of historical buildings. Under Church's direction, successful conservation work was performed at Canterbury and Chichester Cathedrals, and on century-old stone carvings at the Chapter House, Westminster. Before treatment, a touch of the finger sufficed to bring away the surface of the carving; afterwards the stone was as sound as that newly quarried, and harder.73

Church's testimony to the House of Lords Select Committee, 1906

Church's activities at Westminster were fittingly concluded when he was invited in 1906 to present evidence to a House of Lords Select Committee that was appointed to inquire into the incomplete decorative state of the Palace of Westminster.74 Very little had been done in the half-century since the disbanding of the original Fine Arts Commission: large wall spaces remained bare and many plinths and recesses reserved for sculpture were still unoccupied.75 The Commission sought general guidance concerning the relative suitability of paintings in fresco or oil, of tapestries and mosaics for their intended purpose, together with information about their likely permanence.

The Committee, convened under the chairmanship of Lord Stanmore,76 included the earls of Plymouth,77 Lytton78 and Carlisle,79 who between them possessed no small expertise in the subject, as witnessed by their membership of the governing bodies of the leading London galleries, no less than their informed questioning of the witnesses. The Earl of Carlisle, as a student and great patron of the arts, and an accomplished painter in his own right, was particularly effective in furthering the aims of the enquiry. The panel of witnesses consisted of 16 of the foremost British artists, including Sir Edward Poynter, President of the Royal Academy, and the most reputable painters, sculptors and architects of the day. Significantly, several of them, when asked to enlarge on technical points, referred to Professor Church as the expert best placed to provide reliable information.

In this distinguished assembly of Peers and Academicians, Church once again outlined the technicalities of fresco work, its attendant difficulties and the risks posed by unfavourable environments. He now felt justified to present his matured views in a more critical and decided form than had been possible in his Memoranda, going so far as to express the opinion that ‘lime or carbonate of lime ought not to enter into [… the composition of murals]’. In response to specific questions concerning plaster of Paris, he discussed its suitability instead of lime as a fresco backing: as a sulphate it was certainly impervious to the action of sulphuric acid but suffered from the drawback of its very slight but distinct solubility in water; moisture liable to be deposited from damp air during temperature fluctuations needed to be strictly excluded to avoid erosion of the mural fabric.80 In the light of the sum of his experience Church inclined to favour Gambier Parry's ‘spirit fresco’ technique,81 although this was in fact a modified form of painting in oils, sharing with fresco work nothing but the name and the use of a—very differently prepared—lime mortar ground.

Church's testimony was evidently not neglected when in 1910 and 1927 the last two important groups of historical murals82—now funded from philanthropic rather than Government sources—were installed: they were painted in oils on canvas, and the finished paintings were attached to the walls afterwards. These commissions brought the great scheme of the mural decoration of the Palace to a close.83


In the final analysis, the full aims of the original Fine Arts Commission of 1843 were not completely realized. Its high purpose of combining the embellishment of the Palace of Westminster with a patronage that would revive a tradition of historical fresco painting was frustrated, largely by the accidents that befell several of the frescoes, and their general fragility, which made their conservation a constant anxiety. Yet the bold Westminster experiment inspired similar schemes—though on a less magnificent scale—elsewhere in the country,84 and has transmitted great art treasures to posterity.

It was Church's merit to halt the decay of the Westminster frescoes at a critical juncture, to conserve them over a 12-year period by his personal attention, and to give instructions for their future care. With his insight into both the technical and aesthetic aspects of the problem, he wisely employed the mildest possible procedures, being conscious of the danger of doing more harm than good in these delicate operations.

He looked on these activities as a labour of love, and was from the first emphatic in offering his services without thought of remuneration. He not only provided expert advice but also performed a great many chemical analyses and practical trials, and participated personally in the actual restoration work, supervising his assistants on an almost daily basis for weeks on end. Successive Commissioners of HM Works expressed their appreciation of his services ‘placed gratuitously at the Government's disposal that left their Board under a deep sense of obligation’ and transmitted these sentiments in their official Reports to Parliament. In 1909 Church received the honour of knighthood in the Royal Victorian Order; it was no doubt his public-spirited service, as much as his distinguished standing in the academic world, that was thus recognized.

Since Church's days, and especially during the past 50 years, the conservation scene has undergone a profound transformation. The restoration, repair and conservation of paintings, works of art and museum pieces, previously the domain of dedicated individuals85 (usually attached to museums or galleries) or small commercial firms of restorers, who more often than not regarded their procedures and materials as trade secrets,86 has passed into the hands of a recognized profession, based on systematic study. Its activities were formalized in 1950 by the establishment of the International Institute for the Conservation of Museum Objects, and the appearance in 1952 of its journal, Studies in Conservation. The practice of conservation has thus become a legitimate branch of the applied sciences, involving the pursuit of the appropriate scientific, historical and allied disciplines relating to both its technical and artistic aspects.

Laboratories have been installed in the major museums and galleries dealing with the routine conservation work, and engaging in research. Their work has increasingly benefited from the adoption of modern instrumental techniques, both physical and chemical, such as infrared photography, polarizing light and electron microscopy, and combined gas chromatography–mass spectroscopy, the powerful analytical tool that permits the chemical identification of the components of complex mixtures, using minute specimens unobtrusively removed from a painting or artefact. Periodic international and local symposia serve as platforms for the presentation of papers and the exchange of information. The remarkable advancement of the subject is also reflected in the appearance of substantial treatises on the conservation of every kind of object (including wall paintings87) that take increasing cognizance of strict scientific principles.

In this active and vigorous field, Church may justifiably be regarded as one of the pioneers, and his early contributions deserve their due recognition among the wide-ranging research and teaching activities of his long scientific career.


Grateful acknowledgement is made to the expert help and courtesy of the staffs of the British Library, the Library of the Royal Society, and the House of Lords Record Office.


    1. Sir Charles Barry (1795–1860) RA (1841) FRS (1840), architect of the Travellers’ Club (1831) and the Reform Club (1837). His designs for the Palace of Westminster were chosen from 97 entries. Building work of the Palace, although essentially complete in 1852, continued for several more years, finally under the direction of Barry's architect son, Edward Middleton Barry. Oxford Dictionary of National Biography 4, 111–120 (2004).

    2. Reports of the Select Committee on Arts and Manufactures 1835–36; Parliamentary Papers, V, 375 (1835); XXI, 43 (1836).

    3. Sir Charles Lock Eastlake (1793–1865) RA (1830) FRS (1838), English painter, President of the Royal Academy of Arts (1850), Director of the National Gallery (1855), and author of seminal works on the art of painting. Oxford Dictionary of National Biography 17, 591–594 (2004).

    4. Reports of the Royal Commission on the Fine Arts: 1, XXV, 105 (1842); 2, XXIX, 197 (1843); 3, XXXI, 169 (1844); 4, XXVII, 151 (1845); 5, XXIV, 253 (1846); 6, XXIV, 281 (1846); 7, XXXIII, 267 (1847); 8, XXII, 349 (1849); 9, XXIII, 329 (1850); 10, XIX, 441 (1854); 11, XXIV, 201 (1858); 12, XXXIII, 213 (1861); 13, XVI, 317 (1863).

    5. Clare

    6. Anon., ‘Catalogue of the Cartoons, being designs for frescoes to be painted on the walls of the Palace of Westminster … sent for exhibition in Westminster Hall’, 4° (London, 1843) (British Library SM 7807.1.40).

    7. Charles Heath Wilson (1809–1882), architect, administrator and educationist, Director of the Government School of Design. Oxford Dictionary of National Biography59, 497–498 (2004).

    8. Peter von Cornelius (1784–1867), German painter, renowned for his monumental murals in public buildings, first in Munich (from 1819, where he became Director of the Academy, 1825), and later in Berlin (1841). His influence is regarded as having initiated the revival of fresco painting in Germany and subsequently elsewhere in Europe.,

    9. Frank A. J. L. James (ed.), The correspondence of Michael Faraday, 4 volumes (Institution of Electrical Engineers, 1991–99, continuing), vol. 3 (1996), p. 260 (Letter 1627: Faraday to C. L. Eastlake, 22 October 1844) and p. 262 (Letter 1628: C. L. Eastlake to Faraday, 23 October 1844).

    10. See notes 30, 43, 49, 51, 52 and 53 below.

    11. Royal Commission,op. cit. (note 5), Report for 1847.

    12. ‘Money expended in decoration of the Palace of Westminster with fresco paintings and statuary’, Parliamentary Papers, Cd. XL, 637 (1860). — ‘Return relating to paintings in fresco, ordered by the Fine Arts Commission, terms of engagement with each Artist, sums voted on account,of each painting, and sum each Artist has received’, Command Paper XXXV, 679 (1861).

    13. Hansard, CLXIV, p. 1547 (1847).

    14. Wilhelm Ostwald (1853–1932), Nobel laureate (1909), professor in Leipzig, was one of the leading physical chemists of his generation. In addition to his fundamental discoveries he made contributions to the chemistry and physics of colour, including the development of a colour scale. See J. R. Partington, A history of chemistry, 4 volumes (Macmillan, London, 1961–70), vol. 4, pp. 595-600 (1964).

    15. Autobiography: Arthur Herbert Church, Records and recollections (privately printed for the author by John Bellows, Gloucester, Parts I and II, 1899 and 1909; editions of 40 copies for private distribution). Obituary: A. P. Laurie, ‘Sir Arthur Herbert Church, KCVO’, J. Chem. Soc. 109, 374–379 (1916). In 1917 Church's widow, Lady Jemima Church, arranged the printing for private circulation of the several Obituary Notices and Addresses that had appeared in the press and in the journals of societies of which her late husband had been a prominent member: Arthur Herbert Church, KCVO, MA, DSc, FRS, FSA (Baynard Press, London, 1917); Oxford Dictionary of National Biography11, 576 (2004).

    16. A good modern account of fresco painting is given in

    17. Church quoted these figures on the authority of Dr Samuel Rideal (1863–1929), a leading London public analyst and one of the originators of the Walker–Rideal Test for disinfectant activity. Rideal was President of the Society of Public Analysts (1918). Who was Who, vol. 3, p. 1144 (1929–1940); Oxford Dictionary of National Biography 46 , 918 (2004).

    18. In a further variant, the silicate solution was added to the water colours at the painting stage.

    19. C. W. Cope, who was one of the participating artists, subsequently revealed that the frescoes in the Poets’ Hall were painted on plaster spread on a framework of laths, fixed some inches from the masonry; damp was trapped in the intervening space without means of escape, and exerted its destructive effect (C. H. Cope, Reminiscences of Charles West Cope (Richard Bentley & Son, London, 1891), p. 158. In 1871, J. C. Horsley pronounced his work and that of his fellow artists of this apartment to be ‘utterly dilapidated’, and begged that it might be screened from public view.

    20. Letter from Eastlake to Prince Albert, dated 28 July 1851 (R. A. (W), F.31/1).

    21. Cope lamented, ‘how much of life had been wasted in as it were, writing on the sand … time's effacing finger began to obliterate at one end, while we were painfully working at the other’ (Cope, op. cit. (note 30), p. 257).

    22. J. C. Horsley wrote later, ‘None of us knew that fresco-painting required not only fresh plaster on which to work, but fresh air to preserve the work when done. … The Thames was the main sewer of vast London and … was charged with foul and most destructive gases … while coal gas was pouring forth its destructive powers night and day’ (quoted in Bond, op. cit. (note 2), p. 84).

    23. Sir Frederick Augustus Abel (1827–1902) FRS (1860), leading expert on explosives, inventor of smokeless gunpowder (‘Cordite’), was successively Chemist to the War Department and official Scientific Adviser to the Government; he was President of the Chemical Society (1875–77). Oxford Dictionary of National Biography1, 62–63 (2004).

    24. John Percy (1817–1889) FRS (1847), metallurgist, established metallurgy as a distinct scientific discipline. Oxford Dictionary of National Biography 43, 732–733 (2004); Dictionary of Scientific Biography10, 513 (1974).

    25. According to an Office of Works record, certain frescoes had on one occasion (1873) been washed with warm water, but this was drawn from the nearest well, and containing saline matter, was unsuitable for the purpose, for which distilled water is essential (see Church Memorandum I, note 39 below).

    26. A. H. Church, ‘Concerning the Wall Paintings in the Palace of Westminster (With introductory letters by the First Commissioner of HM Works and by Professor Church); Memorandum I, The Royal Gallery; II, The Peers’ Robing Room; III. The Queen's Robing Room’ (Her Majesty's Stationery Office, London, 1895) (C 7651, LXXIX, 261–268, 1895).

    27. A. H. Church, ‘Concerning the Wall Paintings in the Palace of Westminster (With prefatory letters); Memorandum IV, The Upper Waiting Hall; V, The House of Peers’ (Her Majesty's Stationery Office, London, 1896) (C 8054, LXVII, 275–279, 1896).

    28. A. H. Church, Concerning the Wall Paintings in the Palace of Westminster (With prefatory letters); Memorandum VI, The Royal Gallery, VII. The Queen's Robing Room (Her Majesty's Stationery Office, London, 1898), (C 8893, LXXII, 51–54, 1898).

    29. Daniel Maclise (1806–1870) RA (1840), historical and portrait painter. The two frescoes in the Royal Gallery are considered his masterpieces. Oxford Dictionary of National Biography35, 837–841 (2004).

    30. Finding the plain technique on the required large scale unmanageable, Maclise wished to resign the commission. However, encouraged by the Prince Consort, he went to Berlin to study the ‘stereochrome’ method with its chief exponents, Wilhelm Kaulbach and Peter von Cornelius (see note 11 above), and employed it with success.

    31. William Dyce (1806–1864) RA (1848), historical painter. He painted other notable frescoes in All Saints’ Church, Margaret Street, and for the Prince Consort, in the Summer House, Buckingham Palace, and in Osborne House. Isle of Wight. Oxford Dictionary of National Biography 17, 461–465 (2004).

    32. The frescoes represent the chivalrous virtues (Mercy, Courtesy, Generosity, Hospitality and Religion), illustrated by themes from the King Arthur Legend. They are 11 feet high and range in width from 6 feet to 22 feet.

    33. John Rogers Herbert (1810–90) RA (1846), portrait and historical painter. Oxford Dictionary of National Biography 26, 705–707 (2004).

    34. Charles West Cope (1811–90) RA (1848), historical painter, Professor of Painting to the Royal Academy. Oxford Dictionary of National Biography 13, 311–314 (2004).

    35. John Callcott Horsley (1817–1903) RA (1864), historical and genre painter. Oxford Dictionary of National Biography 28, 197–198 (2004).

    36. After Church's adverse report, the panels were indeed covered with what was described, in 1954, as ‘thin boards papered with a diaper pattern, themselves in none too good repair’ (Boase, op. cit. (note 6), p. 346.). However, most recently, all eight frescoes have been resurrected by careful restoration and are once again on view (see Hay and Riding, op. cit. (note 83 below), pp. 95–97).

    37. The magnitude of the task is illustrated by the fact that Maclise's ‘Wellington’ and ‘Nelson’ between them covered an area of some 1000 square feet. The operations of 1894 in the Robing Rooms and the Gallery continued uninterruptedly for nearly two months, from 2 October until 23 November.

    38. These were, in the Peers’ Corridor, eight panels painted between 1859 and 1866 by C.W. Cope depicting events in the reign of Charles I and in the Commons’ Corridor eight more, by E. M. Ward, illustrating the reign of Charles II.

    39. Introduction by the First Commissioner of HM Works to Church's Memorandum VIII, op. cit. (note 42).

    40. Figures supplied by Dr F. Clowes, Chief Chemist and Superintending Gas Examiner to the London County Council. Although burning illuminating gas was a minor contribution to the total atmospheric pollution, it was disproportionately harmful in confined spaces.

    41. Correspondence in Gas World (25 August 1906) and Journal of Gas Lighting (21 August 1906).

    42. Sir Thomas Edward Thorpe (1845–1925) FRS (1876), Professor of Chemistry at Leeds (1874), Imperial College London (1885), studied (inter alia) phosphorus compounds, edited the Dictionary of Applied Chemistry (7 volumes, 1921–27).

    43. Memorandum by the Commissioners of Works, Parliamentary Papers, Cd 2930, CIX (1906) (including correspondence and evidence by Dr T. E. Thorpe).

    44. Arthur Pillans Laurie (1861–1949), lecturer in physics and chemistry at St Mary's Hospital Medical School (1895), Professor of Chemistry of the Royal Academy of Arts (1912), member of several official scientific committees, and author of numerous scientific works related to paints and painting. Who was Who, vol. 4, p. 665 (1941–1950).

    45. Sharon Cather and Helen Howard, ‘The use of wax and wax resin preservatives on English mediaeval wall paintings: rationale and consequences’, in Case studies in the conservation of stone and wall paintings. Preprints of the contributions to the Bologna Congress, 21–26 September 1986 (ed. N. S. Bromelle and P. Smith) (International Institute for Conservation of Historic and Artistic Works, 1986), pp. 48–53.

    46. Ann Ballantyne (and eight participants of the symposium), ‘The removal of wax preservative from English Wall paintings’, in Conservation to-day (Papers presented at the United Kingdom Institute of Conservation, 30th Anniversary Conference London, 1988), pp. 135–141.

    47. The conservation of English wall paintings (Central Council for the Care of Churches, 1959), p. 4.

    48. The incrustation beneath a cornice of St Paul's Cathedral contained, according to Church's analysis, 73.8% gypsum, 2.2% calcium phosphate and 1% each of carbon and tar.

    49. One litre of water at room temperature dissolves ca. 2 g of gypsum (CaSO4,2H2O) but only 0.0025 g of barium sulphate under the same conditions.

    50. As early as 1862, Church patented a form of this process, which involved additional alternative treatment with a dialysed solution of silica: A. H. Church, ‘Improvements in the means of preserving stone from the injurious action of atmospheric and other influences’, British Patent No. 220 (1862). See also idem, ‘Notes on a process for the preservation of building stones’, Chem. News 22, 205 (1870), and letter to The Times, 19 November 1904.

    51. Report from the Select Committee of the House of Lords on the Palace of Westminster. Together with the Proceedings of the Committee and Minutes of Evidence. House of Lords Sessional Papers, 256, Vol. III, pp. 317–391 (His Majesty's Stationery Office, London, 1906). This verbatim report of the four days’ proceedings gives full details of the often divergent opinions of the witnesses. The exchanges between the Chairman, a former great colonial governor, and the eminent artist-witnesses, being no less great individualists, led to occasional terse although always urbane passages.

    52. In the Royal Gallery, for example, where the two vast Maclise frescoes continued in splendid isolation, there were still 15 panels to be filled up. Two of the witnesses (W. S. Lethaby and S. C. Cockerell) referred in the most uncompromising terms to the ‘bleakness and coldness of certain parts of the palace’, and deplored their disfigurement by such vulgar necessities as telephone boxes and refreshment bars. They both championed the cause of tapestries as the most desirable and practical decorations.

    53. Arthur Charles Hamilton Gordon, Baron Stanmore (1829–1912), colonial administrator. In his retirement he was an active member of various House of Lords Committees. Oxford Dictionary of National Biography 22, 860–862 (2004).

    54. Robert George Windsor-Clive, 1st Earl of Plymouth (1857–1923), Paymaster-General (1895–96), First Commissioner of Works (1902–05), Trustee of the National Gallery (1900), Chairman of Trustees of the Tate Gallery.

    55. Victor Alexander George Robert Bulwer-Lytton, 2nd Earl Lytton (1876–1947), grandson of E. G. Bulwer-Lytton, the novelist, and son of E. R. Bulwer-Lytton, Viceroy of India and poet (Owen Meredith). Statesman and colonial governor. Served on the Advisory Council of the Victoria and Albert Museum, and the governing bodies of several societies with cultural objectives. Oxford Dictionary of National Biography 34, 995–997 (2004).

    56. George James Howard, 9th Earl of Carlisle (1843–1911), artist and politician, wealthy patron of the arts, owner of Castle Howard and its art treasures, friend of foremost painters, Chairman of Trustees of the National Gallery. Oxford Dictionary of National Biography 28, 354–355 (2004).

    57. The well-known mural artist, Professor G. E. Moira (1867–1959), one of the witnesses, had used plaster of Paris mortar empirically in his work with success and was delighted to have his practice rationalized by Church's scientific interpretation.

    58. The East Corridor of the Palace received (in 1910) a group of six compositions illustrating the Tudor period, and St Steven's Hall (1927) eight large panels, relating to the building of Britain, all by different artists.

    59. These included D. G. Rossetti and William Morris's ceiling frescoes at the Oxford Union (1857) (which, however, survived for no more than 30 years), Ford Maddox Brown's murals in Manchester Town Hall, and F. L. Leighton's large representations of ‘The industrial arts of war and peace’ at the Victoria and Albert Museum (done in spirit fresco).

    60. See, for example, the contributions of David Perry, Krystyna Barakan and others, to the paper of Ballantyne, op. cit. (note 68), pp. 136 and 138.

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