at the time of the Union. The nineteenth and twentieth centuries In 1812, the family leased the estate to the Ropers and removed their valuable possessions to Loftus Hall in Wexford. The lands and castle were then used for dairy farming and fell into disrepair. To quote a contemporary account from 1838: Crossing the Dodder by a ford, and proceeding along its southern bank towards Rathfarnham, a splendid gateway at left, accounted among the best productions of that species of architecture in Ireland, invites the tourist to explore the once beautiful grounds of Rathfarnham Castle, but they are now all eloquently waste, the undulating hills covered with rank herbage, the rivulet stagnant and sedgy, the walks scarce traceable, the ice-houses open to the prying sun, the fish-pond clogged with weeds, while the mouldering architecture of the castle, and the crumbling, unsightly offices in its immediate vicinity,…The castle, so long the residence of the Loftus family, and still the property of the Marquis of Ely, subject, however, to a small chief rent to Mr. Conolly, is an extensive fabric,.....The great hall is entered from a terrace, by a portico of eight Doric columns, which support a dome, painted in fresco with the signs of the Zodiac and other devices. This room was ornamented with antique and modern busts, placed on pedestals of variegated marble, and has three windows of stained gloss, in one of which is an escutcheon of the Loftus arms, with quarterings finely executed. Several other apartments exhibited considerable splendour of arrangement, and contained, until lately, numerous family portraits, and a valuable collection of paintings by ancient masters. But, when it is mentioned, that this structure has been for years a public dairy, and the grounds to the extent of converted to its uses, some notion may be formed of their altered condition. In 1852 it was bought by the Lord Chancellor, Francis Blackburne whose family resided there for three generations. The property developers Bailey & Gibson acquired the castle in 1912 and divided up the estate. The eastern part became the Castle Golf Club, the castle and the southwestern portion were bought in 1913 by the Jesuit Order and the northwestern part was devoted to housing. The Jesuits are an order renowned for their education and one of them; Father O'Leary S.J. constructed a seismograph. This machine could detect earth tremors and earthquakes from anywhere in the world