Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/141

 Fes. 16, 1872. THE BUILDING NEWS. 125 THE BUILDING NEWS. —__@—_ LONDON, FRIDAY, FEBRUARY 16, 1872. OUR FRESCOES. T will be within the recollection of many of our readers that, after repeated failures to discover the causes of decay, the frescoes in the Palace of Westminster were placed temporarily under the care of a chemist, who succeeded in arresting the vola- tile colours by the application of an indurat- ing}fluid. The experiment was viewed with considerable interest in the art-world—an interest enhanced by the circumstance that it was conducted by a gentleman whose name was unknown in the prior investigations upon the subject. The Department of Works, the artists who were called on to examine Mr. Wright’s proposals, and the public at large have, however, abundant cause for satisfaction of the issue of the undertaking. The frescoes are in a great measure saved from destruction. The apparently simple method by which the object was achieved commended it to the good opinion of the benchers of Lincoln’s Inn, who commis- sioned Mr. Wright to treat the magnificent picture by Mr. Watts in their hall in the same manner as he had already treated the frescoes at the Houses of Parliament. It was one thing, however, to restore the vanishing pigments used by the great painters ; quite another to explain how and why they had disappeared, or define new rules for insuring their permanence. The first object was gained; the second seemed still very far indeed from a satisfactory settlement. Mr. Wright had, in the first instance, nothing more than a pretty accurate knowledge of the action and inter-action of chemical substances, and a ready fund of sterling sense to fall back upon, in his primary en- deayours to solve the vexed problem. He sought information from the hands and lips of the painters engaged upon the frescoes; carefully noted whatever promised to furnish a clue to the remarkable phenomena he saw in the decaying works; compared observations with every one, whether professional or em- pitic, who claimed ability to shed light on any point; and experimented largely in the composition of cements and the use of colours. The outcome of his researches is the produc- tion of a report, which has, we believe, the en- tire concurrence of the Slade Professor of Fine Art at University College, who was associated with him in the commission : whereof the leading points may, after criticism, furnish rules of inestimable value, allay the general uneasiness which prevails, and give a new impetus to an art which aims to be as im- perishable in its nature as the walls upon which it is displayed. The examination of examples has been con- ‘fined by Mr. Wright to those which were acces- siblein England. There were tLe works of Dyce, in the Queen’s robing room; of Cope and Ward in the corridors of the Houses of Par- liament ; of Cope, Herbert, Horsley, Tenniel, and Watts, inthe Poet’s-hall; of Cope, Dyce, Horsley, and Maclise, in the House of Lords ; of Watts, in the dining-hall of Lincoln’s-Inn; of Wurms and Fischer, executed in 1855, in the chapel of Stonyhurst College ; those painted by Borgini, in 1755, at the church of West Wycombe, and in the loggia and colonnades of West Wycombe House; by Burnici, in 1760, at Rivers Abbey ; by Barker, in 1820, at the house of the Rey. Mr. Morgan, Bath ; by Severn, in 1845, in the marble hall at Gatton; and by Armitage, in the Roman Catholic Church at Islington. The majority of these works were more or less affected in various ways, with respect to which Mr. Wright, instead of minuting the injury to each distinct example, describes in order the kinds, the marks, and the causes of deterio- ration or decay, and concludes with a list of pigments that may, in his opinion, be em- ployed with perfect safety, provided, of course, that proper care and prudence be shown in the preparation and formation of the groundwork or backing. The injuries, then, are of two classes: those which affect the intonico, depending on causes not connected with the work of the artist; and those which affect the colouring, originating in the work of the artist or in the materials he employs. In the first class are included : (1) liability of the intonico to con- tract, crack, and fall away from the wall sur- face ; (2) roughness and unevenness of sur- face ; (3) occasional pastiness, and want of absorbence ; and (4) variations in the absor- bent quality, limiting the time during which the artist can work successfully. The first of these divisions embraces in its turn four distinct varieties of cracks, of which some are confined by the work of the day, and are bounded by the joints in the intonico; others are of variable length, extending through the work of the day and into adjoin- ing parts, and not limited by the joints; others, again, are smaller, running into and interlacing each other, giving a broken appearance to the day’s work, and in bad cases rendering it possible to de- tach easily some portions of the intonico from the ground; and the last variety pre- sents a reticulated condition of the intonico, which, under close inspection, is found to consist of a large number of very minute cracks running into each other on all hands, but not of sufficient depth to endanger the stability of the picture. It is gratifying to record Mr. Wright’s observation, under the head of intonico, that the national frescoes are comparatively free from faults which might jeopardise their permanence. The causes of cracks are, moreover, all capable of being effectually remedied in future works. They are due, we are told, to want of age in the lime-paste, or to the use of an undue propor- tion of lime-paste—the plasterer making his admixtures by sight (or ‘‘rule of guess”) in- stead of by weight; to the contraction of the wall beneath; to improper mixtures, which may be obviated entirely by the use of lime of due age and consistence, and sand, in ac- curate proportions; to the imperfect mix- ture of lime and sand; to bad plastering, or to roughness and inequality in the grain of the sand, for which substitutes are suggested— e.g., ground quartz, pumice, glass, and burned flints, capable, in combination with lime-paste, of forming a sound intonico ; to the deteriora- tion of lime by exposure, or to difference of temperature and in the moisture of the atmos- phere. An atmosphere completely saturated with moisture offers the most favourable condi- tions for the purposes of the artist. Defects of colouring are by far the most ex- tensive and serious, yet none of the recently executed works are without some evidences of permanence, at least in portions. Perfect stability and absolute rottenness are found in the work of the same artist, in the same picture side by side, and often in positive con- tact in one day’s work, as, for instance, where an indistinguishable beard rests upon a finely- executed chin that retains the freshness of a living subject. Such defects are multiform, and are calculated to impress the mind with the conviction that to the studies of history, of idealism, of anatomy, and of drawing, our schools of painting should add the study of chemistry as it bears upon their art. There are (1) discoloured spots, not removable by friction, sometimes with, at others without, looseness in pigment or in- tonico; (2) the total disappearance of the pigment used by the artist, or the substitution of a colour not intended; (3) a milky haze, obscuring the design; (4) the detachment of the pigment from the intonico as a sort of loose powder ; (5) detachment of the pigment in flakes, owing to looseness of ground; (6) detachment in flakes, without looseness of ground ; (7) detachment of both pigment and ground in one united flake ; (8) unsound- ness of pigment and ground generally ; and ) the appearance of minute white spots, amp penetrating from behind, chemical in- compatibility or impurity in the pigment, and the use of water containing lime in solution, are assigned as causes of defects 1, 2, 3. The employment of certain colours is put forth in explanation of the remaining faults, with the exception of the last; that is found only in the great picture of the ‘School of Legislation,” in Lincoln’s-inn Hall, and its course has hitherto baffled Mr. Wright’s vigilant search. Inno single instance has yellow ochre been used with perfect safety in any modern work,and half the injuries examined are due to this pigment. It is not durable, and it destroys other pig- ments, as noted respecting the fresco of Mr. Watts, at Lincoln’s-inn, and the works of Messrs. Cope and Horsley, the late Mr. Maclise, and Mr. Tenniel, at the Houses of Parliament. There is danger also in the use or terra verte mixed with lime-white as a ground, from the variable and uncertain con- dition of ordinary lime-white, the use of freshly-prepared ivory black, and the laying of coat upon coat of colour over some portion of the intonico. On the other hand, the list of safe colours is not so limited as might have been feared. The blues are ultramarine and cobalt ; the reds—Indian, light, vermilion, and colcothar of all shades; the greens— chromiums of all shades ; the yellows—lemon (Windsor & Newton’s), cadmium (pale and orange), sienna, (raw and burnt) ; the browns —umber (raw and burnt) and Cologne earth ; the blacks—lamp, ivory, vine, and Cologne earth, burnt. No doubt an improved know- ledge of the chemistry of colour will one day yield an extended list. eee eet WORKS AT PEMBROKE COLLEGE, CAMBRIDGE. HE new buildings at Pembroke College, by Mr. Waterhouse, are approaching completion. 'The work has been carried out with unusual care, and the materials, both in quality and quantity, are above the average. Expense has evidently not been grudged where it could add to the permanence and solidity of the structure. The floors through- out are fireproof, being carried by wrought iron girders imbedded in arches of lias. lime concrete. The soffits of the latter are visible, and constitute the ceilings. We can hardly say that this arrangement is satisfactory in effect. To display construction is all very desirable, but it is desirable at the same time to make the construction worth displaying. A fireproof floor, without doubt, may be made to look very well from the under side, but to accomplish this end ueeds study and foresight. A random arrangement of arches and girders can no more be relied on to make a good ceiling than a random arrangement of doors and windows to make a good eleva- tion. As far as at present appears, there is some deficiency of study in this detail of construction at Pembroke College, and what- ever ornament may be applied to the ceilings, their general shape will never be altogether pleasing. ‘lhe elevations are of red brick, with bands and dressings of Casterton stone. The style adopted is a mixed one, and the details, as in much of Mr. Waterhouse’s work, are curiously unequal in merit. In general composition the building is picturesque and appropriate to its purpose. ‘The skyline is a good one, and the ridge-chimneys among the best we have ever seen. The mullioned windows, which are hardly good enough for late French Gothic, and hardly bad enough for debased Perpendicular, do not please us so well; while the uninteresting lozenge pattern parapet, and the spiritless-stuffed-and- dried looking gurgoyles are the least pre- possessing of all. There is some excuse for tameness in the design of necessary features : they must be introduced whether the designer succeeds or fails in their treatment; but the case is different with purely orna-