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
In a recent response to John Carmichael, I
referred to some capabilities of the Dialist's Companion program. It seems
that a number of people where unaware of these features. After checking
the Help page, I discovered that we evidently did not document them - so no
wonder that they are
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
The mystery concerning the disc with the incription AU LEVANT THE THEBES
SURGIT A PARIS LE NORD on the 12-hour line of the sundial with the obelisk as
gnomon, at the Place de la Concorde in Paris becomes more intricate.
Denis Savoie, President of the Commission of Sundials in the Astronomic
