The Blue Book - a piece of history
As I might have mentioned before, next year marks the 50th anniversary of the completion of the Lovell telescope. Over the last few weeks I have been talking about this with various members of staff at the Observatory as some of us feel that we really need to mark the event in a big way. When doing "Ask an Astronomer" I usually tell the audience a bit about the history of the Observatory, why we came to be here in the first place. Today, after some digging, I found some important pieces of that history.
After working on the development of radar during the war years, Bernard Lovell, a member of staff in the physics department of the University of Manchester, wanted to carry on his research. When he tried to use his radar equipment in the physics department in Manchester he found that there was too much interference from the trams which, at that time, ran up Oxford Road, right through the middle of the campus. He began looking for another site he could use temporarily while he used his equipment to search for radar echoes from cosmic ray air showers. When he discovered that the botany department owned a site at Jodrell Bank in Cheshire, he sought permission to take his equipment there.
What Lovell and his fellow researchers soon realised was that the signals they were detecting came not from the cosmic rays which they were trying to detect but from the ionised trails left by meteors as they streaked through the upper atmosphere. Over the next few years they aquired and built various other telescopes around the site to continue their research, not least of which was the 218-foot transit telescope, a giant wire construction which (as it was constructed on the ground) could only see the sky in a 30 degree wide stip as it drifted overhead. This telescope was used to survey what they could see of the sky at a variety of low frequencies at which the telescope was capable of operating (one of the factors which determines the highest frequency at which a telescope can realistically operate is the accuracy of its surface; the smoother the surface, the higher the maximum operating frequency).
Eventually Lovell came up with his plan to build a 250-foot fully steerable radio telescope. In his book "The Story of Jodrell Bank" he describes the early years and the process of constructing the telescope, both in terms of the political, financial and personal stuggles involved. Chapter 8 of that book describes the decision of a committee of the Royal Astronomical Society to endorse his proposals for construction of the telescope. The Council of the RAS passed a resolution to this effect and Lovell and Blackett (Professor of Physics at the University of Manchester) then went to the DSIR (Department of Scientific and Industrial Research) to ask for funding to carry out a design study. This was granted and so Husband, the consulting engineer on the project, began to draw up detailed engineering proposals. To accompany the engineering study, Blackett told Lovell to put together a detailed report on the scientific aspects of the project which included the researches carried out at Jodrell up to that point, what the telescope was intended to observe and the scientific reasons for the design of the telescope. These reports, together with information on the beam shape, gain, and control system, were typed up as a memorandum to be passed to the DSIR before any further decisions were to be made on whether the project would actually be given permission to go ahead. As the memorandum was bound in blue cloth it became known as the "Blue Book".
This afternoon, while looking through a wooden cabinet trying to find the original negatives of the photographs of the construction of the telescope used in Lovell's books, I came across an original copy of the Blue Book. When I took it back over to the main building I had fun showing people what I had found. I don't now how many copies were made, but I don't think there are many copies left now. Several people who have worked at the Observatory for many years (decades in some cases) said that they had never seen a copy before! Rather than leaving it in the damp of the archives it is now safely locked away in a warm room. It really amazes me how a lot of the old archive material is treated. Someday soon I plan on going up to the archives in the Rylands library in Manchester as a lot more of Lovell's records are up there. It's all useful for next year's anniversary...