We went to the country fair in Birr Castle at the end of the Summer on our way home from Clare. It is my second visit there and I was disappointed to find that the great science museum they had there is now closed, but the telescope remains and this is the history of it in short form. In 1845 William Parsons, the Third Earl of Rosse at Birr Castle built the largest telescope and the most powerful instrument of its time, and using it he discovered 16 spiral galaxies. Scientists from around the world came to admire this great feat of engineering. It remained the largest reflecting telescope in the world for 70 years. Today it is restored and is still working today. I hope sometime I will have the opportunity to see it working.