How the Lime Tree Observatory was Established

The owner of Lime Tree Farm, Peter Foster has always had a keen interest in astronomy, and over the years has built a few astronomical buildings on site. He has been a friend of The York Astronomical Society (YAS) for many years.


The YAS has its own observatory on the outskirts of York and whilst renovating an old telescope that was originally at Durham University, they realised they needed a new focuser making. One of the YAS members had been in touch with John Wall, the inventor of the Crayford Eyepiece Mount. It was this contact with John Wall that would be the genesis of the Lime Tree Observatory.

John Wall built a 24inch (600mm) reflecting telescope in the early 1970s.  At the time of its construction, it was the largest amateur-built telescope in the World.  For many years it took pride of place at the Crayford Manor House Astronomical Society (CMHAS) in Kent.  Sadly, in 2012 the CMHAS were told by the local council that they had to move their observatory and the telescope. But they had nowhere to go or even store the telescope.  John was worried that his masterpiece would be scrapped, and so got in touch with York AS asking if they would like to "rescue" it. They agreed, and approached Peter at Lime Tree, asking if he would like to be the new custodian of this great instrument.  Peter gladly accepted!

So in September 2012 YAS members travelled to Crayford to dismantle the telescope along with the dome it was housed in, and brought it all back up to Grewelthorpe. In the years that followed the project was put on hold for various reasons, but in the summer of 2014 building work began on the new observatory.  Due to their age, both the telescope and dome threw up a great many engineering problems during reassembly and so it was early 2016 before the optics were finally put in place and observation was again possible through this historic instrument.

The Lime Tree Observatory opened its doors to the public in the winter of 2016-2017 and nearly 300 people passed through its doors in the first season. John Wall (now in his 80s) followed the project via social media and is simply delighted that his telescope is not only saved, but is once again being enjoyed by the public under the darkest skies it has ever seen.

Due to ill health, John never got to revisit his telescope in its new location.  In 2017 his health deteriorated further and he passed away in January 2018.