Complex sentence: He built a quay to carry coal to Howth lighthouse, at considerable cost to himself, and he was noted for charity, leaving a large sum in his will for the relief of the poor of the parish of Howth.
Split into simpler sentences: He built a quay to carry coal to Howth lighthouse, at considerable cost to himself. He was also noted for charity, and left a large sum in his will for the relief of the poor of the parish of Howth.