Gnomon for Vertical Decliner

   I am debating what type of gnomon to put on a 28d SE decliner at 40.15d 
latitude, 76.60d W longitude.  The perpendicular dial height of 8" should be 
enough and would be part of a large painted mural.  The artwork will be the 
focus, not the gnomon.  I do not want to obstruct the view of the dial 
center, so I was thinking of just a tapered perpendicular pin and just read 
the tip of the shadow.  

   I am also considering a pin hole gnomon and just read the spot of light.  
I was thinking of attaching the gnomon vertically though, and then coming 
out, tilting it to the style angle.  I do not believe I've seen any pictures 
of sundials done this way.  Are there any?  I've only seen it at the end of 
the style from the dial center.  I would have to determine disc and hole size.

   I originally proposed a sundial that included declination lines and 
analemma and would work with either type of gnomon.  Would either of these 
gnomons be appropriate, just for hour lines?  The artist I am working with 
prefers a more simple design with hour lines only and no other furniture.   
So would a more traditional gnomon be better and just read the edge of the 
shadow if no other furniture is included? 

   Many of the dials I've seen pictured in Europe, are of the style with 
bracing on each side.  I was wondering how accurately they are installed 
without the ability to check with a digital level years ago?  I feel the 
gnomon needs to be installed first to get the right distance to the dial 
center to allow for any distortion when the gnomon is attached so the tip of 
the gnomon is in the right location compared to the dial center.   I realized 
the larger the dial the more fuzzy the shadow becomes.  I am just trying to 
avoid any added errors.

   I am also concerned about the effects of the attachment points of the 
gnomon discoloring the paint from the water running down the wall.  I am 
considering some type of brass but I am not sure what is the best way to 
anchor the gnomon to a masonry wall.  I have not really checked out what's 
available in hardware or anchors that will not rust or corrode over time.  I 
do like vertical dials because they are somewhat vandal proof but is there 
any way to attach a gnomon that would also be easily repairable if broken 
off?  

   I was just thinking of having a small permanent hole for the dial center 
to aid in laying out the lines now and in the future repaints.  I do not know 
if this sundial will come to fruition, but I just was wondering if others had 
experiences in attaching a gnomon to a wall or suggestions or opinions on 
laying out an accurate sundial on a wall so I can be assured that gnomon is 
correct and the dial center is truly at the center so my measurements will be 
correct when I lay out my lines.

Thanks in advance,

Ken Clark 

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