THE STEM 
radius of a log. Repeat the geo- 
metrical principle upon which such 
a cut is described as “ tangential.” 
It passes through the medullary 
rays and the annual rings diagonally 
(Fig. 136), and is the cheapest way 
of cutting timber, since the entire 
log is made into planks and there 
is no waste except the “slabs” and 
“edgings,” as shown in Fig. 138. 
The cut ends of the medullary rays 
appear on the surface as small lines 
or slits (Fig. 187), and give to this 
kind of plank its peculiar grain- 
ing. The wavy or “watered” 
appearance of the annual rings 
(Figs. 133, 136, 140, 141), so often 
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Fic. 138.— Diagram to show 
the common method of sawing a 
log. The circles represent rings 
of annual growth: R, R, diam- 
eter of the log; 7, r, 7 and f, t, t, 
boards cut perpendicular to it, 
giving for the two or three cen- 
tral ones radial; for the others, 
tangential, cuts. The waste por- 
tions are the ‘‘slabs”’ and ‘‘ edg- 
ings,’”’ shown in the dark seg- 
ments at R, R, and the small 
triangular blocks, e, ¢, «. 
seen in cheap furniture and in the woodwork of cheaply 
constructed houses, is caused by the tangential cut, which 
strikes them at various angles. 
135. The radial, or quartered cut, 
Fic. 139. — Diagram illustrat- 
ing the “quartered ”’ cut :d,dand 
d' d', radial cuts (diameters) by 
which the log is “ quartered”’; 
ce, center of the log; 7, 7, radii 
passing through the middle of 
each quarter, parallel to which 
the planks ¢, ¢, fare cut. The 
circles represent rings of annual 
growth. 
familiar to most of us in the “ quar- 
tered oak.” of commerce, passes 
through the center of the log and 
cuts the rings of annual growth per- 
pendicularly, giving it the “striped” 
appearance (Fig. 135) seen in the 
best woodwork. It gets its name 
from the practice of dealers in first 
sawing a log into quarters and then 
cutting parallel to the radius pass- 
ing through the middle of each 
quarter, as shown in Fig. 139. In 
this way each cut strikes the rings 
perpendicularly, but except in the 
case of very large logs, only narrow 
