At 01:16 PM 11/30/96 EST, Bob Terwilliger wrote:
>To Roderick Wall and All,

>I noticed that some of the responses Roderick posted were apparently sent to
>him personally and not also posted to the mailing list.  

Yes, I did this inadvertently.  Here is my experience (I think I sent this
after Roderick had posted his summary) in more detail than I originally sent:

Finding that granite is impractical without sandblasting equipment, I turned
to slate.
Slate is a soft stone which can be easily carved.  I bought a piece of
polished slate about 16 inches on each side from a local stonemason place.
(I appreciate the fact that everybody won't have a stonemason place up the
street as I do)  One could possibly use the natural cleft slate (which is
very cheap) sold for garden walks, but a sawn and polished piece, like what
was traditionally used for blackboards, gives very nice results.  I started
by printing out roman numerals using my computer printer on a piece of heavy
card stock.  I cut them out with a razor blade to make stencils and used
these stencils to transfer them onto the slate with white ink.  Similarly, I
printed hour lines on a piece of paper which I taped to the slate but
transferred these by marking extensions; then removing the paper and
reconnecting the lines.  I then turned the inked lines into engraved lines
by scratching in multiple several passes using a metal tool and a straight
edge.  The straight lines were very simple to do by making several passes
and progressively cutting a V-shaped groove.   The roman numerals were a
little trickier.  I used a straightedge for the straight parts and did some
free-hand digging for the serifs.  I started out trying to use a sculptor's
pointed chisel I got at an art supply place with a light hammer but found
this tended to chip, and I had more success with a little tool I had that is
normally used to score plastic laminate for cutting.  The tool is simply a
plastic handle attached to a flat hardened steel shaft with a sort of
shark-tooth 
shaped protjection at its tip. One could probably make something as good or
better with a grinding wheel and a thin file.  If you make a mistake or a
slip of the hand (as I did a few times) and you haven't carved too deeply,
the mistake can be sanded out using fine wet-or-dry sandpaper.   

The brass gnomon was another story.   

Jack Aubert
E-Mail: [EMAIL PROTECTED]
Homepage: http://www.cpcug.org/user/jaubert

Reply via email to