On the death of his father John was compelled to give up school and seek employment in a tobacco shop. In 1858 he left the position and became a teacher in the Christian Brothers schools. In 1860 he showed signs of failing health; accordingly the Brothers transferred him to one of their schools in Waterford, in the hope that the climate there would prove more beneficial to his impaired health. However, after residing in that town for a time it was seen that the looked-for improvement did not materialize, and he grew worse instead of better. During the following twelve months he was assured by the best medical advice available that his health would not permit him to continue his studies, and that in order that it be restored he would do well to live in some place having a mild and dry climate, such as is found in the Madeira Islands. For several reasons this was impracticable, so he went to Cork to wait until he could find a suitable climate in which to live. While staying in Cork he lived at Ashburton, at the western end of Clanmire Hill, for about one year. While here he improved greatly in health and strength. The War of the Rebellion in the United States had started a few months before he came to live in Cork. Toward the end of November, 1862, he read in the Cork _Examiner_ an announcement of the first combat between armored ships that had occurred about two weeks previously; that is, the battle between the _Monitor_ and _Merrimac_ at Hampton Roads, Va., in which the little _Monitor_ defeated the _Merrimac_, of twice her bulk and power, after a short contest. Just before the remarkable duel the _Merrimac_, ignoring the guns of her opponent, the wooden ship _Congress_, sank her by striking her with her massive iron stem. The _Cumberland_, another ship like the _Congress_, lying in the water near her, did not wait to be similarly rammed, but made haste to run aground on the nearest shallow place. But this did not save her, as the _Merrimac_ attacked her and set her on fire with her heavy guns, while ignoring her fire, which did very little harm. This epoch-making contest in Virginian waters astonished naval authorities the world over, especially in England, whose main reliance for the maintenance of their power was placed in the "wooden walls," and in the bravery and skill of their seamen. The English nervousness was due to the demonstration at Hampton Roads that wooden ships could be no more of a hindrance to an armorclad than the _Cumberland_ and _Congress_ were to the _Merrimac_, and that if the Yankees built a few more monitors and sent them across the Atlantic quickly, they could come to London by water absolutely unhindered and destroy London and all the English navy within reach. All the English naval depots could, with practically no hindrance, be treated similarly within a few months, and an end made of English oppression from which it could never recover.