The 2nd Earl of Rosse, known as William Parsons, was an Irish nobleman and astronomer born in 1800. He is best known for his work in the field of astronomy, particularly for constructing the Leviathan of Parsonstown, which was the largest telescope in the world during the 19th century. This telescope allowed him to make significant observations of celestial bodies. In addition to his contributions to astronomy, the 2nd Earl of Rosse was also involved in various scientific endeavors and was a member of the Royal Society. He played a key role in promoting scientific research in Ireland until his death in 1867.