Stone of the Museum Building

“The science of architecture… may be considered as combining with appropriate design the conversion and fit application of the solid materials which compose and cover the surface of the globe…  This science, therefore, of all others, especially requires an acquaintance with geological phenomena and a knowledge of the various products of the simple inorganic masses of rocks…  These are the materials which the architect has to employ, and in which… he has to embody his ideas.” (Wilkinson 1845)

Through matching existing geological knowledge with new research on the fabric of the building and associated historic quarries we have documented twenty two different stone types in the Museum Building.


The concealed exterior walls of the building are constructed of Calp, which is an impure muddy limestone that underlies Dublin and contributes to its name “Dirty Old Town”.

The Calp blocks are externally faced with 9 inches of Ballyknockan Granite from Co. Wicklow.

The exterior dressing, comprising carved stringcourses, quoins, pillasters and capitals, are in Portland Stone and the tympanum above the door, bearing the College crest, is in Caen Stone.

The coloured roundels on the exterior of the building provide modest polychrome decoration on a plain granite backdrop.  Portland Stone frames enclose segments of native marbles, including Connemara Green Marble, Cork Red limestone, Carlow black slate, pale yellow chalk limestone from Scawt Hill in Antrim and Donegal White Marble.


The interior of the Museum Building is a magnificent, didactic gallery of stone.  The walls are constructed of ashlar Caen Stone.  The steps of the imperial staircase, later replaced with Portuguese Creme Sintra Unata limestone, was originally executed in Portland Stone; the rest of the staircase consisting of Caen Stone.  The balcony floors are of the same material as the steps of the staircase.  The back stairways leading to the basement are in Ballyknockan Granite, while the walls of the basement are Calp.

The banded arches above the upper and lower side arcades , together with the large arch dividing the double dome, are alternating pale Portland Stone and red Mansfield Sandstone.  The domes display mosaics of colourful enameled hollow brickwork.

A border of purple Welsh Pen-yr-Orsedd Slate surrounds the entire floor of the stairhall.  The polychrome floor was originally paved with red Yorkshire flags, Portland Stone slabs and black slate tiles from Carlow.  When the floor was relaid in the 1980s the Portland Stone was replaced with Creme Sintra Unata limestone and some of the black slate tiles were replaced with Kilkenny black limestone.  The black slate re-appears in some of the external roundels and in the ornamental stone inlay above the inner arches between the entrance hall and the stairhall alongside Connemara Marble, Cork Red Marble and Scawt Hill Marble.  The architects incorporated in their interior and exterior polychrome decoration the same native polished stone, creating a continuity of design throughout the building.

The polychromatic columns consist of various coloured Irish limestones, Connemara Marble and Lizard Serpentine from Cornwall.  The distinctive, fine-grained, fossiliferous, sienna coloured limestone came from Clonony in Co. Offaly.  The mottled reddish-brown limestone was sourced from Armagh.  The black “reef limestone” from Michelstown consists of a fine-grained mud lime matrix, which contains many cavities infilled with sparry calcite.  The grey, crinoidal limestone, which is very similar to a popularly used stone from Clonmacnoise, was obtained from Castle Caldwell.  The widely known, valuable, black limestones are from Galway and the Black Quarry in Kilkenny.  The vibrant red limestone originated from Cork.

The carved arches above the central arcade and the capitals and bases of columns are in Portland Stone.

Geology dictates decoration in the Museum Building

William Richard Manderson, proprietor of the Killaloe and Dublin Marble Works, supplied the polished stone for the Museum Building.  Despite the extraordinarily beautiful finished product, the decoration of the building using Irish marbles was not a faultless process.

Disputes between Messrs. Deane, Son, and Woodward and the Board of Trinity College Dublin arose during the fitting of multi-drum marble columns on the ground floor of the Museum Building.

On 4th May 1855, Deane wrote, “My attention having being directed to… the defects that appear in some of the marble columns now erected in the hall of the lecture rooms… I regret to find that it is inevitable that the college must permit in some places small pieces to be inserted in the columns, and broken lengths, where the marble in block did not allow the work to be otherwise performed“.

Here, Deane acknowledged geology’s influence on design.  There are both monoliths and multi-drum columns on the lower story.  The length and thickness of beds in Irish marble quarries determined the sizes of raised blocks, which later dictated the sectional make-up of each column.  Manderson declared, “the very great difficulty of procuring perfect columns of such large diameter and length”.  

Deane continued, “The difficulties that had to be overcome of unopened or partially opened quarries, and the apathy on the part of the proprietors, must be taken into account, but it is to be hoped that the good example now set by the college of largely using native marbles may induce greater facility to be given and exertion made towards the proper development of the resources of the country”.

Regardless of the many difficulties involved, Deane defended the learning curve surrounding marble quarrying and fabrication in return for splendid Irish marble columns and decoration in the Museum Building.

The architects heeded the Board’s disapproval of the structural irregularity of the ground floor columns when later fitting the upper level columns.  The portion sizes of the multi-drum columns on the upper floor are matching.  Furthermore, in contrast to the almost enigmatic colour distribution of marble columns on the lower story of the Museum Building, a balanced arrangement of marble is observed on the upper story with green and red columns amid dark-coloured, wall-mounted half columns at the ends of each arcade.

Considering decorative stone types for the Museum Building

“The physical or external character of the marbles constitutes the chief consideration with reference to their use for decoration or ornamental architecture, their colour, and internal structure being the most important… Their chemical character has reference to… their capability of receiving and retaining a certain polish”.

Many characteristics were undoubtedly considered when choosing the decorative stone for the Museum Building.  The constitution of the stone determines the aesthetic qualities, which are at the forefront of the selection process.  For example, the incorporated fossils and mineral assemblages decide the texture and colour of the stone.  The chemistry dictates the stone’s ability to receive and retain a polish.

“The more crystalline and least earthy marbles are the least durable.  The internal structure determines the durability of the stone and its weight bearing capacity.  The compact or finely granular crystalline marbles being superior to those which are largely crystalline or of a slaty texture”.

The internal structure must have been an important factor when selecting decorative stone for the Museum Building as the columns are not merely decorative veneers, but an integral part of the engineering of the building.  All of the selected stone types for the columns are of a compacted, fine-grained nature, thus promoting structural stability.

The University Church, St. Stephen’s Green, Dublin, contemporary with the Museum Building, and the extant entrance hall to the Museum of Irish Industry (1850), 51 St. Stephen’s Green, Dublin, showcase a wider variety of Irish marbles than the Museum Building.  In contrast to the Museum Building the marbles in both of these buildings are incorporated mostly as wall panels and do not have to function as dimension stone, thus enabling a wider assortment of less durable marbles to be included.

To clean or not to clean?…



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