Z, MISC. PUBLICATION 225, U.S. DEPT. OF AGRICULTURE 
other cases a series of alinement charts have been prepared which 
permit the direct determination of values in multiple form. There 
are included also certain other tables giving data more or less com- 
monly used in forest calculations. 
In the tables the unit value on which the conversion is based is 
indicated as 1. Conversion units are not carried beyond six decimal 
places. When the final digit is not exact but represents a rounding 
to the nearest value, it is italicized. Figures in parentheses ( ) below 
the decimal figure are approximate values for use in rough calculations 
where a high degree of accuracy is unnecessary. Figures in brackets [ 1 
below the decimal figure are exact values. 
The tables are adapted for ready use. An example or two will best 
illustrate this. Given the average height of a stand as 42.67 meters, 
to convert to feet: In table 1, column 9 is headed ‘‘ Meters’’; on the 
same line with the figure 1 in this column will be found all the various 
conversion factors that are likely to be needed by the forester; the 
factor under ‘‘Feet”’ is 3.280833, by which the given height, 42.67 
meters, is converted to 139.993 feet. Similarly, a cubic centimeter 
of a certain tree seed weighs 0.35 gram; how much will a bushel, 
avoirdupois, of this seed weigh? In table 9 the factor for pounds per 
bushel, found by locating first the figure 1 under ‘Grams per cubic 
centimeter” is 77.6893. This factor gives 27.19 pounds per bushel. 
In all the tables, United States units of weight are understood to 
be avoirdupois unless otherwise specified. 
TABLES 
TABLE 1.—Length; unit conversion factors, with approximate values 
Inches Links Feet Yards Rods Chains!]| Miles ? ene _| Meters nae 
31 | 0. 126263 | 0: 083333 | 0.027778 OOO SOS | ie ea ee ee 2. 540605 ONO2 5a | are 
(4%) [Me] [6] (400) (24) (140) 
7. 92 1 0. 66 0. 22 0. 04 QSOS esa eee 20. 11684 OS2OMG Sa za 
(74) [5] [Moo] (20) (%) 
12 } 1.515152 31 | 0.333333 | 0.060606 | 0.015152 | 0. 000189 30. 48006 0. 30480/ 0. 600305 
(14) [44]. (Me) [Yo] (30) (0) 
36 | 4. 545455 3 31] 0.181818 | 0.045455 | 0. 000568 91. 44018 0. 914402 0. 000914 
(4%) (4%) (42) (Mo) 
0. 3937 OOO I OL ORV pO ONO G BY | La i 4] OkOla Ear 
%) (40) (40) (40) 
39. 37 4.97096 | 3. 280833 1.09367 | 0. 198838 0.04971 | 0.000627 160 1 0. CO1 
(40) (5) (%) (40) | (4600) 
Furlongs 
198 25 16.5 5.5 1 0. 25 | 0.003125 0. 025 5. 02927 0. 005629 
[14] [420] [40] (5) (4400) 
792 100 66 22 4 1 0. 0125 Q. 1 20. 1168 0. 020117 
[Yo] (20) (40) 
Siete sax 5, 280 1, 760 320 80 1 8 | 1, 609. 347 1. 609347 
(1,600) | - (434) 
Dien eee 660 220 40 10 0. 125 i 201. 168 0. 201168 
[34] (%) 
2c, Vee Ee 3, 280. 83 | 1, 093. 61 198. 838 49. 7096 0. 62137 4. 97086 1, 000 i 
(200) (50) (8) (5) 
1 Surveyor’s chain; the engineer’s chain=100 links of 1 foot each is not used. 
2 1 nautical mile (termed ‘‘knot’’ as unit of velocity) =1.1516 statute miles=1.85325 km=1 inch of are on 
the earth’s surface at the Equator. 
3 British units: 1 yard=0.914399 m; 1 foot=30.47997 em; 1 inch=2.539998 em; 1 hand=4 inches=10.16 
cm; | span=9 inches= 22.86 cm; 1 cubit=18 inches=45.72 em. 
41 millimeter=0.1 em=0.03937 inch =0.00328 foot. 
