The day-long operation involved removing the 58 feet wooden tube of the telescope, from its mountings and placing it on a truck for the 25-mile journey.
The telescope, which was built by the third Earl of Rosse in 1844 and was the largest in the world until 1917, is being restored as part of a multi-million development plan at the castle to restore it to its former glory and build a science museum.
In the 1880s, scientists and personalities from all over the world travelled to Co Offaly to view the sky through the telescope with its 6 feet diameter mirror which was cast in the castle moat by the earl and his workers.
Through the giant telescope, the earl discovered that the galaxies were spiral in shape and its creation allowed human eyes to peer further into space than ever before.
Yesterday the eyes of Birr were all on the telescope as it was taken from its mountings and brought through the town for restoration by a company called Universal Works.
The project manager for the company, Mr Kieran O'Brien, of Murrary O'Brien and Partners, Dublin, said the removal of the telescope from its base had gone smoothly. He said the barrel of the telescope would be restored using as much original material as possible.
When that work is completed, it will be returned to Birr and relocated over a specially cast mirror for which tenders are now being sought by the Birr Historic Science Museum.
The original mirror, made of tin and copper, which is currently in the Science Museum in London, is to be returned to the new science centre. This is expected to be completed in 1998.
The Birr Castle telescope being removed for restoration in Woodford, Co Galway. Photograph: Frank Miller