Ireland is situated in the North Atlantic, between the degrees fifty-one and a half and fifty-five and a half North, and five and a quarter and ten and a third West longitude from Greenwich. It is the last land usually seen by ships leaving the Old World, and the first by those who arrive there from the Northern ports of America. In size it is less than half as large as Britain, and in shape it may be compared to one of those shields which we see in coats-of-arms, the four Provinces - Ulster, Connaught, Leinster, and Munster - representing the four quarters of the shield.