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THE YOUNG SCIENTIST. 
wmwimiijmww 
Fig. 19. 
Fig 20. 
END 
1 
R 
\ 
0 
1 
— 1 
c 
B 
0 
P y 
X 
0 
\ 
D A 
Fig. 21. 
Fig. 18 shows thfi method of holding the short 
jointer or fore plane, when jointing thin stufr. 
s s, is the stuff being jointed, n the screw-chops, 
p the screw head, R the bench, and w the fore 
plane. 
Note.— An absolutely true surface is a theoreti- 
cal impossibility, though surfaces are made 
so true that the most accurate measurements are 
not capable of discovering their defects. 
Fig. 19. This cut shows how the longjointef 
should be held when jointing or truing stuif. 
Fig. 20, shows a common gauge, e is the head. 
F the stem, p the spur, s the tightening screw. 
Fig, 21 shows the end, side and plan of the 
mitre box, o o and p shows sections of the sides 
and bottom, c, a, b, d, show how the box is cut 
for a mitre, x shows how it is cut for a square 
cut. K, R, o, show the side, with the cuts. 
