Hi Mike,
I've had responses that indicate that Melville used a variety of methods to
attach gnomons, from leading them in, fitting them with flanges underneath to
the twisted tenons that you mentioned. No 2BA screws, though! So I am
convinced that the ones on the Dunmore (Ireland) dial are
In 1884 the British Association for the Advancement of Science adopted a
thread form and series, primarily for use in precision equipment. It was
inspired by one used in the Swiss watch and clock industry, and was
formerly sometimes called the Swiss Small Screw Thread System; but is
now
Dear dialling colleagues,
I'm helping to restore a Richard Melville (worked 1832-1871) slate dial with
multiple gnomons. The gnomons are held in with 2BA brass screws using square
nuts. The gnomons themselves are nominally 1/4 inch thick but with
considerable variation, i.e. not the modern
Dear John,
I believe that Melvillemade his gnomons such
that they have two tangs that poke through the slate. These are then each
bent in opposite directions. I am sure that he would not have used screws.
I can send you photographs if that helps.
Regards,Mike CowhamCambridge
UK
I'm
Message text written by INTERNET:sundial@rrz.uni-koeln.de
I'm helping to restore a Richard Melville (worked 1832-1871) slate dial
with multiple gnomons. The gnomons are held in with 2BA brass screws using
square nuts. The gnomons themselves are nominally 1/4 inch thick
Can anyone tell me when
