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Transcription
narrower; for tropical giants, they might have to be
wider. It is desirable to base the measurements upon
the largest board that you will need, and to have the
pieces of all the boards cut to those measurements by
the lumber yard or wood-working shop where you
buy the materials. The minor alterations necessary in
the smaller boards can be made with a hand saw after
they are assembled.
The two principal pieces of each spreading board
should be of very soft wood. California redwood and
eastern white pine are excellent, but western white
pine is too hard. It does not matter what wood is
used for the smaller pieces.
MATERIALS FOR ONE SPREADING BOARD
Two pieces of soft wood, 12" x 3" x 5/6" at one edge
and 3/8" at the other, as shown in fig. 3. This slope of
Fig. 3. End of one of the two principal pieces of a spreading
board.
the top surface of the boards gives the wings of the
mounted insects an upward tilt which tends to offset
a natural tendency of the wings of pinned specimens
to droop.
Two pieces of wood, 7" x 3/4" x 1/2". The thickness
of these pieces combines with that of the narrower
edge of the principal boards to determine the height
of the specimens upon their mounting pins, and is
therefore important. The other dimensions may vary
a little, if desired, although their length should at least
equal the total width of the completed article, and
their width must be great enough to receive several
small nails without splitting.
Three pieces of wood, 12" x 3/4" x 1/2". The length
of these pieces is their only significant measurement,
but the cabinet maker who cuts the pieces would
probably like to make all the small ones from the
same strip of material.
One piece of cork or balsa wood, 10 1/2" x 1" x 1/8"
approximately. Balsa wood strip of suitable size is
carried by many hobby-craft stores, and it is some-
times possible to obtain sheet cork from a concern
dealing in linoleum and similar floor coverings.
TOOLS AND SUPPLIES
Small-headed wire brads, some one inch and some
three-quarters of an inch in length.
Carpet tacks, about a quarter of an inch long.
A little glue.
A hammer.
A small saw.
ASSEMBLING THE SPREADING BOARD
Place the two seven-inch strips, one broad surface
down, parallel to each other and a foot apart. On top
of these, and at right angles to them, put one of the
two wide boards. Match the corners at the thick edge
of the board, and nail the pieces together as shown at
the top of fig. 4. Use the one-inch brads at the outer
corners, the three-quarter inch elsewhere.
Fig. 4. First steps in assembling a spreading board.
Lay the second board parallel to the first, with the
thin edges facing each other and enough space be-
tween them to accommodate the body and legs of an
insect. Fasten with brads, as shown at the bottom of
fig. 4. Grooves 1/4", 3/8" and 1/2" in width will probably
be most useful.
Turn the assembly over. For a quarter of an inch
on either side of the central space, spread the bottoms
of the boards with glue. Cover the gap with a strip of
balsa wood or cork. Since, in use, this strip must
bear considerable strain, it should also be secured
with a number of large-headed tacks, as shown in
fig. 5.
Still working on the underside, place the three
long wooden bars on top of the short ones, and at
right angles to them, parallel to the large boards. The
outer pair should match the boards at the corners,
while the middle one must lie directly above the space
between them, over the cork or balsa wood strip.
Nail all three in place with one inch brads as shown
in fig. 6.
Unless the groove has been made extremely wide,
the ends of the short cross-pieces will be protruding
at one side of the spreading board. Cut these off