2 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 [ ] 

 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 3.280835, by which the given height, 42.67 

 meters, is converted to 139.995 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 27.15 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 



Eods 



Chains l 



Miles 2 



Centi- 

 meters 



Meters 



Kilo- 

 meters 



3 1 



0. 12626-5 



Oi) 



1 



1. 515152 



(1H) 



4. 545455 



m) 



0. 04971 



(Ho) 



4. 97096 



(5) 



25 



100 



0. 083335 

 [M2] 

 0.66 



m 



31 



3 



0. 032808 



(Ho) 



3. 280835 



16.5 



66 



5,280 



660 



3, 280. 85 



0. 027778 

 [He] 

 0.22 



0. 333335 

 [X] 



31 



0. 01093(5 



(Ho) 



1. 09361 



5. 5 



22 



1,760 



220 



1, 093. 61 



0. 0050-5 



(Hoo) 



0.04 



[Hz] 



0. 060606 



(He) 



0. 181818 



(HO 







2. 540005 



(2H) 



20. 11684 



(20) 

 30. 48006 



(30) 

 91. 44018 



U 



100 



0. 0254 



(Ho) 



0. 201168 



(H) 



0. 304S01 



(Ho) 



0. 914402 

 (Ho) 

 0.01 



1 



5. 02921 



(5) 



20. 1168 



(20) 



1, 609. 347 



(1,600) 



201. 168 



1,000 





7 92 



0.01 



[Hoo] 



0. 01515.2 



[He] 



0. 045455 



(H2) 







12 



36 



3937 



0. 000185 

 0. 000568 



0. 000305 

 0. 0009U 



(%) 



39.37 

 (40) 



0. 198838 

 (HO 



4 



320 



40 



198. 838 

 (200) 



0. 0497^ 

 (Ho) 



0.25 

 [H] 



SO 



10 



49. 7096 

 (50) 



0. 000621 

 (Heoo) 



0. 003125 



[H20] 



0. 0125 



[Ho] 



1 



0. 125 



[H] 



0. 62137 



(H) 



0.001 





Furlongs 





198 

 792 



0.025 



[Ho] 



0.1 



8 



1 



4. 97096 

 (5) 



0. 005025 

 (Hoo) 



0. 020117 



(Ho) 



1. 609347 







(1H) 

 0. 201168 







(H) 









1 Surveyor's chain; the engineer's chain = 100 links of 1 foot each is not used. 



3 1 nautical mile (termed "knot" as unit of velocity) = 1.1516 statute miles = 1.85325 km =1 inch of arc on 

 the earth's surface at the Equator. 



3 British units: 1 yard = 0.914395 m; 1 foot = 30.47997 cm; 1 inch = 2.53999S cm; 1 hand=4 inches=10.16 

 cm; 1 span=9 inches = 22.86 cm; 1 cubit=18 inches=45.7# cm. 



* 1 millimeter = 0.1 cm = 0.03937 inch = 0.00328 foot. 



