The Building of Galactica Quinnash
 


      [A 1989 talk, given by Paul, assisted by John Nash, on their construction of a large telescope between 1979 and 1982. Among his papers there were no more than 50 lines of notes for the talk, scrawled over 3 sheets of A4, simply jottings, since he knew its history. They have been transcribed below, with an introduction to establish some background, but the real story is in the 70 or so slides taken by Paul. These illustrate the various parts and to a lesser extent the procedure, but it is impossible for me, a person with little understanding of astronomy and no knowledge of telescopes, to identify many of the parts depicted in the slides, let alone put them into a sequential order to make a coherent historical statement. With the slides at B.A.S. perhaps some day a member may be able to do so.

     Typically, Paul never discussed “Galactica Quinnash” within the family in case we found the subject boring, and I understand that the Nash family moved to Cornwall, and the telescope no longer exists at 9 Tavistock Road, Knowle.    N.V.Q. 3/2007.]

 

     It was in March, 1979, that the challenge of building a fairly large telescope was initiated, when John Pedlar sold us a length of 8.5 inch glass fibre tubing. At the time I was living in a flat in Pembroke Road, Clifton, with no access to a garden, so the obvious site was John’s garden at Tavistock Road, where he had a  small workshop, and enough space to create a building to house the telescope, ie. an observatory.      

     There were three elements to the enterprise : the observatory, the groundwork - from 4 feet below the surface upwards, and the telescope. All had to be designed from the start.

     The observatory was basically a large wood and brick shed, but needed a flat roof, of which a 50% flap could be pulled up and over to give an open observation area. It was completed in 1979 but was unsatisfactory, being very difficult to manipulate, and a much better sliding roof was fitted in the summer of 1980. It was renovated in 1982.

     Groundwork consisted of two objectives. Firstly, a conduit had to be constructed to bring electricity from the house to the observatory for sockets and lighting. Secondly, a hole had to be dug to a depth of 4 feet into which shuttering was placed so that concrete could be poured in to create a large cube which would be a firm base for the pyramidal block where the R.A. axis would be fitted.

     The telescope was eventually assembled in the observatory from pieces put together there, or indoors at respective homes. Apart from the mirror it would be a completely home made telescope.

 

    So, the sequence of “G.Q.” Where specific tasks were undertaken the initial of Paul or John is in brackets.

    The piece of glass fibre tubing purchased in March, 1979.

    Building the observatory, using everyday stuff, from April to the end of the summer, 1979.

    Quotes for 6 inch to 8.5 inch mirrors, from Monstrosity Mounts. Purchase of an H.Wildey 8.5 inch in November, 1979. F L 76 ins. F No 8.7.

(P).

     Mirror and mirror cells. (P).    


     The mid section of the tube required a door, and the fitting of old and new cell to the tube. (J).                                               

     The rack mount, spider, and two flats. (P).

     The turret, finder, and camera accessories. (J).

     The observatory building of 1979 had a new roll-back roof with rails fitted in 1980.

     Electricity laid on to the observatory in 1980.

     Cradle of wood and metal parts, with an adjusting system. A mount block made and a fork mount, a Picador spindle using a car axle, a pulley wheel and cogging, and declination systems. 1980.

     Drive put on 1981. Also in 1981 there were image problems due to a bad flat that had to be rectified.

    A new block was made for a German mount which replaced the 1980 structures in 1983

  

   How does the telescope work ?   Prime focus. No camera lens or eyepiece, the mirror focusing direct. The magnification depends on the focal length, but it can be doubled with a converter. Projection :- here we have the eyepiece, but still no camera lens. Set up the telescope as if you were looking through it, put on the camera (no lens) and with a small focus adjustment you see the object focused in the camera. The results depend upon a good mount. Our old mount was OK for the planets and the moon, but for deep skies there was too much wobble. So we had to buy a new mount and build a 3T base for it. 

   What has it achieved ?  John will now run the projector while Paul talks through a series of “GQ” astronomical slides, with particular attention given to Orion, Saturn, Jupiter, Mars, Venus, and the Moon.

                                            

                                            Thank You.

     

        [Throughout the notes there is no indication as to what slides were used to illustrate the construction of the telescope and its observatory].