2014:488 - Graduates' Memorial Building, Trinity College, Dublin, College Green, Dublin 2, Dublin

Trinity College Dublin is currently undergoing a general upgrading of the college precinct including the laying of cobbles in Front and Fellow’s Square, which is now being followed by the replacement of the tarmacadam in front of the GMB (Graduates’ Memorial Building), which flanks Library Square on the north. Library Square was an additional square laid out directly east of the Old College in c. 1700. Investigations established that this represents the cemetery attached to the original medieval priory of All Hallows, which originally stood in what is now Front Square. Only the eastern range of Library Square, known as the Rubrics, still survives and is the earliest building in Trinity College, built as a residence for the students in c. 1700. The northern and western ranges were added slightly later, in and around in 1723 and built under the supervision of Sir Thomas Drew. John Rocque’s map, dated 1756, shows the fully finished square, which was flanked on the south by Thomas Burgh’s library, now known as the ‘Old Library', begun in 1712. The original Old College quadrangle is also shown to the west, dwarfed by the new Library Square but was demolished shortly after this. The northern range was known as ‘Rotten Row’ and this was only demolished as late as 1897, and replaced with the GMB. Drew recorded finding what he described as ‘the old margin in the college and the landing stage for boats’ on excavation for the building, the ‘old margin’ defined by sands and silts associated with the original slob-lands of the Liffey and the landing stage represented by timber structural remains. Library Square, to the south of the site, is known to contain burials but they lie at approximately 1m below present ground level.

Two test-trenches were excavated at either end of the GMB in June 2014 in advance of the works, which identified a cobbled surface lying roughly 0.2m below present ground level at the eastern end and just 0.14m below present ground level at the western end. This surface was then exposed in a strip running along the base of the GMB with a view to recording it before the site works began. The cobbles were found to be relatively well preserved, lying between 0.25m and 0.3m below present ground level and at their widest point measuring 1.9m and 2.15m in length (north-south). The cobbles themselves were small and rounded, varying from between 0.08m and 0.15m in diameter and laid generally in a north-east/south-west orientation, corresponding to the similar angle of Rotten Row and contrasted sharply with the strict east-west orientation of the GMB. They were set on edge, positioned closely together and formed a very solid, tight surface, bedded in dark brown clay, which was filled with brick, ash, oyster shells and the occasional clay pipe stems. The surface clearly pre-dated the construction of the GMB, as the new building cut through the cobbles, the construction trench averaging 1.45m in width north-south, filled with dark grey silt. The remains of a depressed gully ran along the northern side, the channel of which measured 0.2m in width by 30mm in depth.

A square granite stone was found within the channel of the gully, projecting beyond it on the northern side and measuring 0.42m north-south by 0.46m wide. This had an inlaid square plate of iron on top, measuring 0.26m square, and an iron knob in the south-east corner, measuring 2mm in diameter. It is not certain what this feature was originally but it may have been some sort of statue or column base. It may have been a later feature as the northern side was re-cobbled after it was laid.

Typical profile

0 - 0.03m: Tarmac.

0.03 - 0.15m: Dark grey silty clay layer.

0.15 - 0.25m: Compact infill deposit of dark brown clay with tar, brick and mortar.

0.25 - 0.38m: Cobbled surface.

0.38m: Hard dark brown mixed clay, with, pottery, slate, stone and orange red brick as above.

The cobbles are bedded in the demolition and refuse material, which also contains several fragments of 18th-century pottery (including 18th-century chocolate coated slipware and transfer printed ware). The brick fragments are of a crude brick, bright orange in colour and not of imperial size, possibly hand-made. The colour is very similar to the existing façade of the brick façade of the Rubrics, which was refaced in the late 19th century and therefore the re-faced brick must have been matched in with the original brick. The original brick fragments presumably formed part of an infill deposit, which raised up the ground level in this area in the mid 18th century.

At the northern end, the cobbles were sealed by brick and mortar demolition deposits containing the distinctive orange brick of the Rubrics and presumably originating in the demolition of Rotten Row (the range that preceded the GMB) in the late 19th century. The southern end was sealed by dark brown organic clays, which contained brick, cinders and ash and were clearly dump deposits, the domestic debris from the college itself. The final design for this area has not been decided but all works will be monitored.

28 Cabinteely Close, Cabinteely, Dublin 18