170 
THE YOUNG SCIENTIST. 
inches, and Ik inch thick, and the two 
longer pieces 24 inches by 3 inches, and li 
incn thick. As will be seen from Fig. 2, 
which is a front and end elevation of the 
frame, the tenons are left projecting over 
the front pieces about 2 inches, but only 
on one side. The use of this will be seen 
later on. 
End View. 
Fig. 2.— Front View 
When this has been framed together 
*'dry," that is, merely knocked together 
without being glued, and the projecting 
ends of the frame nicely rounded off, it 
must be laid on one side while the blocks 
are being prepared. The number of these 
latter is in a measure dependent on the 
will of the workman, as only two blocks 
Fig- a. 
Fig. 4. 
Fig. 5 
Fig. 
are absolutely requi're(T, the mitre being 
cut by the wood being placed between. 
But as by the addition of one block the 
mitre trap may be used for " shooting " 
the ends of drawer fronts and such like, 
it will be much better to have lliree 
blocks. Cut these out, therefore, each 8 
inches long by 3 inches square. After fit- 
ting these to the required length, so that 
they will work easily up and down in the? 
frame, two of them are required for the 
mitre, a section of which is shown by Fig. 
3. The other block must be left square. 
Now, take the frame to pieces, and work 
a couple of grooves along the inside of the 
two long sides, and across the end of the 
three blocks. Cut out and fit two tongues, 
of hard wood into each of the grooves in 
the end of the blocks, which will now be; 
of the appearance shown in Fig. 4. 
The frame must now be glued together^ 
the blocks being put in the order shown 
by Fig. 6, the grooves in the frame, and 
the tongues in the blocks allowing the 
blocks to move backwards and forwards; 
in the frame. A screw must next be pro- 
cured out of a piece of boxwood, and must 
measure about 16 inches in length, in- 
cluding the handle, and about 1 inch in 
diameter on the thread. In order to at- 
tach the end of the screw to the block, 
a plate of brass about 2 inches by 1 inch, 
must be fixed on to the end of the screw 
at A (Fig. 5), in such a 
manner that it will, when 
screwed on to the block 
]narked b on Fig. 6, work 
the block backwards or 
forwards by simply turn- 
ing the handle. The tooE 
will now be of the shape? 
shown in Fig. 6, which, 
is a section cut right 
through the centre. To^ 
make a mitre, the wood 
must be placed between 
the blocks c and d, and 
then planed down to the 
level of the frame. To> 
shoot a piece of wood 
square it must be placed 
between the blocks d and 
e. The best wood of 
which to make this tool 
is mahogany, though any hard wood will 
do. To fix it on the bench, place a holdfast 
on one of the projecting tenons, and screAV 
firmly down —Builder mul Wood-Worker^ 
— When desperate ills demand a speedy 
cure, distrust is cowardice and prudence- 
folly. 
