A 'Digges Telescope'
Mr Colin Ronan and Mr Gilbert Satterthwaite
understand that some members are interested in having details of
the optical parameters of the 'Digges telescope' displayed on the
1992 August 16 transmission of The Sky at Night. We therefore present
a diagram. Readers may also care to note that a similar instrument
has been constructed at Leicester University since the broadcast.
Like that of the instrument made by us, its field of view is very
small, and confirms the remarks made by William Bourne, and quoted
in the Presidential Address given in October 1991. 
Ronan, C., J. Br. Astron. Assoc., 102, 339 (1191)