Dr. John O’Donovan BL, (1805-1861), probably the greatest Irish scholar of all time, selection of letters from The Graves Collection Royal Irish Academy. The letters give a snapshot of his genius depth and breath of knowledge and extraordinary industry before his premature death.

http://en.wikipedia.org/wiki/John_O’Donovan_(scholar)

On O’Dalys:
https://durrushistory.wordpress.com/2011/10/08/dr-john-odonovan-the-odaly-family-bards-muintervara-1852-extract/