8 BULLETIN 272, U. 8. DEPARTMENT OF AGRICULTURE. 
TABLE 3.—Average strength values of green cypress in compression endwise and in bending 
for pieces of different weight. 
7, ir- ing 
Wood (air-dry). Compression Bending. 
pacallel to. | | 
grain (crushing Fiber 
strength at stress at |Modulus of 
Specific | Weightper| maximum elastic | rupture per 
gravity. | cubic foot. load, per limit per square 
square inch). square inch. 
inch. 
Pounds. Pounds. Pounds. Pounds. 
0.58 36.2 6, 500 6, 800 7, 800 
04 33. 7 4, 800 5, 600 7, 100 
-50 31.2 4, 700 5, 000 6, 300 
.44 27.5 ADO OTS | ee Sea roe es verse cee oe 
-41 25.6 3, 800 4,500 5, 800 
230 Waid 3, 200 3, 800 5, 100 
.30 21.9 2, 900 3, 600 5, 000 
1 Forest Service Circular 19. Strength tests on cypress have not yet been made at the Forest Products 
Laboratory in connection with the series for commercial woods of the United States, and the figures given 
in Tables 3 and 4 can not be compared with those for other kinds of wood so far obtained in the latter series, 
since conditions of test were different. 
In the above tests the varying strength values of green cypress are 
shown to be correlated pretty closely with the varying weights and 
densities of the wood. Trees on adjacent but dissimilar sites are 
known to produce wood differmg markedly in strength. The first 
test was with a small cypress over four centuries old, grown in a 
“yond” in South Carolina, which proved to be the heaviest and like- 
wise the strongest and stiffest timber tested. 
Similar tests made with air-dry wood (12 per cent moisture) from 
16 cypress trees selected from various portions of the range show, in 
Table 3, the variation in strength values and their general correlation 
with weight. 
TABLE 4.—Average strength values of air-dry (12 per cent moisture) cypress.! 
Wood (air-dry). Average strength in pounds per square inch. 
Compres- Bending. 
sion par- 
allel to 
eee Fiber 
Specific | Weight per} (crushing | tress at | Modulus of | Modulus of 
gravity. | cubic foot. enous aeric rupture elasticity 
it or | limit per | per square | per square 
aaieon square inch, inch. 
inch) inch. | 
Pounds. | Pounds. | Pounds. | Pounds. | 1,000 lbs. 
0.58 36.2 7, 860 9, 000 8, 480 1, 774 
a5 34. 4 6,510 6, 920 8, 120 1, 355 
"52 32.5 7, 290 8,730 11) 350 1, 734 
51 31.9 6, 270 6, 490 7,540 1, 173 | 
_50 31.2 6, 100 6, 470 8, 160 1.173 
"49 30.6 7, 660 8, 380 9, 710 1, 786 
“48 30. 0 7,170 7, 770 9, 350 1,275 
“47 29. 4 6, 890 7, 230 8, 880 1 163 
BAG 98.8 7,740 7, 670 10, 370 1 768 
45 28. 1 6, 070 6, 550 8, 180 1, 406 
44 97.5 6, 760 7, 710 8,900 1 660 
143 26.9 5, 470 5,000 6, 240 892 
142 26.2 5,520 5, 990 7, 030 1, 075 
139 24.4 5, 200 4900 5, 750 841 
37 93.1 4770 5, 120 6, 210 996 
135 21.9 6, 070 6, 550 6, 250 925 
1 Forest Service Circular 19. 
a an 
