The Great Leviathan
Have you heard of the Great Leviathan of Birr? Well in the middle of the 19th century Birr in county Offaly was at the centre of world science and astronomy. Why? Because the inventor of the then largest telescope in the world was William Parsons, third earl of Rosse. He was born on this day, 225 years ago!
This feat was celebrated 50 years ago on television as the Irish Examiner newspaper records:
Tribute to work Earl of Rosse
From Our London Editor
AN estimated quarter of a million viewers here Wednesday night saw a special 20-minue tribute to the work done by William Parsons and his son, Laurence Parsons, the 4th Earl, at Birr Castle.
The present Earl and Countess were interviewed in the programme, one of "The Sky night’ series, by the noted astronomer Mr. Patrick Moore.
For over 50 years (right up to the middle of the first world war) the 72-inch telescope at Birr was the most powerful in the world, and Birr Castle was the undisputed world centre of space research.
A tremendous amount of restoration work has been done in recent years at Birr Castle and as part of the establishment of the museum there two thirds of the original woodwork of the great telescope had been replaced. It was the giant metal mirror, weighing almost four tons, cast by tie third Earl, which led to his discovery of the nature of the galaxies more than 50 million light years from our planet. The speed of light is 186,000 miles a second and the nearest star is 4.5 light years away.
COLOSSAL OPERATION
"Setting out to make a 72-inch mirror today is a colossal operation, and I always think that one of the most amazing points about the Birr telescope is that it was done by one man," Mr. Moore told the viewers.
The wonderful thing is that this absolutely revolutionary job was achieved by the third Earl with the help of half a-dozen Irishmen—blacksmiths, carpenters and farm labourers trained by himself.
William Parsons had to work out the actual percentage of metals used in his mirror, and, as is well known, the thing cracked twice before he got the successful model. The definition it gave was good, even by modern standards, and they correlate completely with photographs from even the 200-inch telescope at Mount Palormar, California. They were the earliest things of their kind ever to be done.
In addition to making the mirror, the third Earl had to make the grinder and all the other tools for constructing the mirror. The massive mechanism which raised the entire telescope up towards the sky when it was about to be used was cast in his own forge. The third Earl always wore a top hat while observing. He was strung up by pulleys 60 feet in the air, "and yet all is perfectly safe," stated a contemporary report.
He also observed "the Owl", a star which has blown an immense shell of gas around it. A great number of drawings made by William Parsons at the eyepiece of his telescope are on view at the museum at Birr Castle. All of these, and his drawings of the planet Jupiter, have been confirmed as very accurate by the latest observations.
The wife of the third Earl was a pioneer of photography. Their son, the fourth Earl, measured in 1890 (after 20 years of study) the tiny quantity of heat sent to us by the moon. The accuracy of his findings has been fully confirmed by modern astronomical mathematicians.
The historic telescope at Birr is surrounded in spring by a mass of daffodils. The box hedges in the grounds of the castle are 200 years old. They are 34 feet high—the tallest in the world.
For more information search the pages of the Irish Newspaper Archive (www.irishnewsarchive.com )