Hello Ray,
The NASS Compendium is the major benefit for NASS members and only available
to members. Treat my note as an invitation to join. The digital download
option cost only $20 per year. We are a not for profit society run by
volunteers. All the membership dues are returned to the members as benefits
like the Compendium. For details see
http://sundials.org/index.php/join-nass/join-nass
Here is the article that provides background on the software written by
Brian Albinson.
Hollander Dial Software
Brian Albinson (North Vancouver, British Columbia, Canada)
I have been interested in sundials ever since I was a youngster,
particularly in how to read mean time. I
remember seeing a large bronze 19th Century dial, I forget where, which had
a worm drive on the dial
face with a knob you turned to match the month. At the time I did not
understand the meaning of EoT.
I graduated in engineering some 56 years ago, in the age of the slide rule
and 8-figure log tables. There
were (I think) at that time only two computers in England, one (MADAM) was
in the next building to
where I did my research in the Reynolds Lab in Manchester UK. It had 20,000
valves (tubes!), occupied
a whole wing and had a mean time between failure of about 5 minutes. I tried
to figure out how to apply
it to my hydraulic problems but binary and mercury delay lines were beyond
me. During my subsequent
career I taught myself the elements of simple programming, acquiring the bad
spaghetti habits of selftaught
programmers; I cannot now follow some of the stuff I wrote.
More recently I saw Fred Sawyer's paper on the Longwood dial and the
mathematics interested me to the
point where I devised an 'engineer’s' approach to determining the analemma
coordinates simply by grid
scanning over every possible point on progressively finer grids and choosing
the point of minimum error.
It turned out that Ken Seidelman had published the algorithm in 1970; I
really now know how Newton
must have felt about Leibnitz. Actually, there does remain a small feature
which remains original;
because I wrote in Excel the visual presentation led me to the idea of the
possibility of distributing the
errors by weighting differently at different times of the year.
When I saw the Hollander Mean Time dial at the recent Vancouver Conference
(see the articles in The
Compendium 13(3), Sep 2006), I thought it would be an interesting challenge
to write the software. I
contacted Hendrik who said he was not going to write a program for general
use so I spent a few days in
the den.
I must extend my thanks to Ben Hoffmann and Warren Thom who took my hand and
provided a hundred
pages of guidelines on how to produce .dxf files from Visual Basic. Also the
wonderfully clear and
concise paper by Fred Sawyer. Fred's method of directing the tangent shadow
to the correct side of the
ellipse, forcing the intersection to be always within the cone shadow, was
inspirational.
As a footnote, it seems that you only need a relatively small portion of the
end of the gnomon to be
conical, this could lead to some very artistic interpretations.
The program, provided as part of the digital bonus with this issue of The
Compendium, comes in a zip
package containing the .exe file and all the .dll run time files needed.
Just double click and the program
should automatically unpack, load the .exe file into the folder you name and
the .dll files into your system
folder.
The program is very easy to use and will display the dial face and cone
development on the screen. In
this mode the dial face and cone development are to different scales.
The Printer option produces scaled output to an 11” x 8.5” paper; the
printer is scaled to print both the
dial and the cone development to the same scale in both x and y directions;
but only one scale is available.
The dxf file option produces dial face and cone development output to the
same scale in different dxf
files. You should choose a file name without the .dxf , the program
automatically adds the .dxf. You can
use your CAD program to edit the .dxf files and produce any scale you want.
Brian Albinson, 3441 Wellington Crescent, North Vancouver BC V7R 3B3 Canada
[email protected]
--------------------------------------------------
From: "Ray" <[email protected]>
Sent: Wednesday, August 19, 2015 10:42 AM
To: "Roger Bailey" <[email protected]>
Cc: "Dan Uza" <[email protected]>; <[email protected]>
Subject: Re: Metal cone
Hi Roger,
I did a search for "NASS Compendium 14-2 "Hollander Dial Software";
unfortunately the link to find a DeltaCAD marco was not available or I
missed it, or perhaps you have to be a member of the North American
Sundial Society to access it. Do you have a direct link to the Marco
for the Hollander Sun Dial?; I am also interested in making one.
Thank you,
Ray
N043., W077.
[email protected]
On 8/18/15, Roger Bailey <[email protected]> wrote:
Hi Dan,
As you consider conical gnomons, pay attention to the conical sundials of
Hendrik Hollander, the winner of the 2006 Sawyer Award. His conical
bi-gnomon sundials could tell clock time. Here is the note on his award.
"The 2006 Sawyer Dialing Prize has been awarded to Hendrik Hollander for
his
innovative design of a mean-time planar sundial with oblique conical
gnomon
and modified hour lines and day curves – resulting in a sundial adapted
to
modern timekeeping while retaining the aesthetic appeal of the familiar
dial
face."
Google his name and sundials to see what his conical sundials can do. A
link
to this article published in the NASS Compendium 13-3 will come up. Also
check the digital bonus with NASS Compendium 14-2 "Hollander Dial
Software".
Regards,
Roger Bailey
NASS Secretary
From: Dan Uza
Sent: Saturday, August 15, 2015 11:16 AM
To: [email protected]
Subject: Metal cone
Hello all !
Any idea how much a metal cone would cost and where to buy it online? The
kind you can use as gnomon - Ebay has loads of punk spikes on offer, but
they are too small.
Thanks!
Dan Uza
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