24Ní Chatháin, Próinséas. "Sir Samuel Ferguson and the Ogham Inscriptions." Irish University Review 16.2 (1986): 160.
Ferguson was fortunate that his wife lit a candle as she waited for him to emerge from the interior of the cave; otherwise he might never have seen the ogham inscriptions. "When Ferguson returned to Dublin, having made a record of the Rathcroghan inscriptions, he found 'that one letter in the inscription was uncertain, indistinct, and blurred.' He rushed and caught the night train back to Roscommon and "'y twelve o'clock next morning he was again at work in the cave.'"