ck 33, held firmly by cramp 11.

Your corner blocks must be a trifle broader than the ribs, and about
as wide as them--also from corner to inner surface, about one and a
half inches. Cut and fit these nicely for future glueing, and then
prepare and bend your pine for linings. This pine must be about
five-sixteenths of an inch broad by about three-thirty-seconds of an
inch thick, cut to taper for inner dressing either before or after
fixing to ribs. These are not too easily bent, but not nearly so
difficult as the ribs; but do not put on too much pressure, or snap
is the result.

It will be necessary to see carefully to the gradation of the depth
of the ribs from one and a quarter inches to one and one-eighth of
an inch, either when they spring from a whole length or from three
separate ones. In any case, my advice is to mark the beginning and
end of each section from the broad end to the narrow, Nos. 1 to 2,
lower; 2 to 3, middle; 3 to 4, upper; so that you cannot well get
wrong in bending, from which would spring the first cause of error.

Having your glue somewhat thin but firm, at the point of setting,
glue and clamp well your corner blocks (your mould being in the
vice) and after that, remove the fitted wood block over the centre
rib (it being now fast at both ends by means of the blocks just
glued), and accurately fit the two small linings there, removing
each end of said lining between block and rib, at either end, and,
by first forcing half-inch chisel where the lining will have to go,
as a sort of slot. This you must also do at the ends of all the
other linings. Now glue the two small ones for centre and carefully
fit and force them end by end into slots, finally placing wood block
33 over glued linings, and clamp firmly with cramp 11. The other
four are much easier to fit and fix; small cramp 2 being used; but
here you must always be sure of a perfect fit all over, or you will
find when taken from the mould there will be apertures, Fig. 16.

[Illustration: PLATE XVI.]

When dry next day, and before you take from the mould, remove most
of the cramps (one or two being left to keep the work fixed) and
very neatly cut and clean all the work, as shown in figure of open
instrument, and go about it in this manner:--the heavy corner blocks
must be reduced with large gouge, and the linings made to fall away
from their _full_ thickness at edge of ribs to fine union with said
ribs at the extreme of their (the lining