It was once suggested to me as an argument against the Irish architectural character and antiquity of the Inchcolm oratory, that its vault or arch was slightly but distinctly pointed, and that pointed arches did not become an architectural feature in ecclesiastical buildings before the latter half of the twelfth century. But if there existed any truth in this objection, it would equally disprove the early character and antiquity of those ecclesiastical buildings at Killaloe, Glendalough, and Kells, in which the arch of the over-croft is of the same pointed form. The over-croft in King Cormac's Chapel at Cashel shows also a similar pointed vault or arch; and no one now ventures to challenge it as an established fact in ecclesiological history, that this edifice was consecrated in 1134, or at a date anterior to the introduction[94] of Gothic church architecture or pointed arches in sacred buildings in England.[95] In truth, the pointed form of arched vault was sometimes used by Irish ecclesiastics structurally, and for the sake of more simply and easily sustaining the stone roof, long before that arch became the distinctive mark of any architectural style. Indeed, in the very oldest existing Irish oratory--viz. that of Gallerus, which is generally reckoned[96] as early as, if not earlier than, the time of St. Patrick, or about the fifth century--the stone roof, though constructed on the principle of the horizontal arch, is of the pointed form. The whole section of the oratory of Gallerus is that of a pointed arch commencing directly at the ground line.[97] "I have," Mr. Brash writes me, and I could not well quote a better judge or more learned ecclesiastic antiquary, "carefully examined the oratory at Inchcolm, and it is my conviction that the pointed arch supporting the stone roof does not in any wise whatever militate against its antiquity, particularly when taking it in connection with the extreme rudeness and simplicity of the rest of the structure, and the total absence of any pointed form in either door or window."[98]