I don't know what Barnes wrote, but it seems to be like the
illustration in Hubbard's book. All of the Ital. Virginals I've worked on
(all anon.) and the single bentside spinet (Benj.Sison, London, ca. 1690)
were made this way, too. It seems to me to be the most reasonable fashion.
For the virginals I've made, I glued up the box guides out of
individual pieces. I draw the instrumewnt as far as necessary on the
bottom. On this, or on a MYLAR drawing, the glued-up guide can be made so
that it fits afterwards. I planed running stock of pear, both of jack
thickness and spacer thickness. All of this was sized. I then cut off
lengths of spacer long enough for the diagonal measurement and of the jack
stock about half that. As well, I cut off pieces of jack stock to the
length between the jacks. Then I glued to each spacer a length of jack
stock to form a step. Starting at one end(fixed to the drawing), I put one
soaped jack blank, a narrow jack spacer with glue, a soaped jack blank and
another piece of stock with glue on the first spacer block forming two
channels and added the next step with glue on the right places so that its
step was correct for the next note, holding these together with a spring
clamp. I then pulled out the soaped jack blanks. I continued this until the
whole was finished. Under way, a few steps had to be slightly reduced in
thickness to maintain the string spacing to the end. As someone else
already commented in his description, the jagged edges had to be cut
straight and the thing veneered on both sides to make it strong enough and
dimensionally stable. Doing it this way give consistent slots that are
absolutely smooth inside and the edges of the jack spacers can be broken
before gluing as well. This can be observed on old Italian hpschd boxslides
which are regularly glued up of spacers between two veneers. One, at most
two, shavings with the plane and the jacks run flawlessly. It sounds like
more work, but actually it is probably less; no dados to cut, no corners to
clean, etc., just lengths of "mass produced" stock.
I have seen what appear to be chiseled slots. I'm sure these
cannot be finished without a broach the size of the finished slot. For me,
that is just too much work and too inaccurate.
regards, Bill
William Jurgenson
Keyboard Instrument Maker
|