Actually, the background engraving on banknotes is done with Guilloche
machines, I've somewhere a picture of one, a highly complicated contraption,
where engravers (burin) where guided by the movement of gears, which where
exchangeable to ratio needed. The Pattern has to be perfect to calculation,
as nice as the Harmonograph is, the pattern is random.
In modern Times, where are securities companies with proprietary software,
who design the guilloche pattern for the banknotes, certificates etc.
----- Original Message -----
From: "Don Wilkes" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, September 20, 2001 9:04 AM
> >From: ibbetson <[log in to unmask]>
> >It's been used for drawing background patterns on currency notes. The
> >device may have been known to Newton, but not by that name or for this
> >The name "harmonograph" may be Anthony Ashton's name (and possibly
> >copyright) for his version of the device.
> I found a nice bit of the history of this machine this morning:
> "The harmongraph was pioneered by the French physicist, Jules Antoine
> Lissajous in 1857."
> Fascinating stuff!