Table 1 (continued) 

 CONVERSION FACTORS 



15 



L. Power: 



1 absolute watt (abs. watt) 

 = 1 abs. joule sec.' 1 

 = 0.238844 ITcal. sec." 1 

 = 14.33062 ITcal. min." 1 

 = 0.23892 cal.i. sec." 1 

 = 14.33527 cal.« min. -1 

 = 0.056868 Btu min.' 1 



1 mean International watt 

 = 1.00019 abs. watts 



1 ITcal. sec." 1 



= 4.18684 abs. watts 



1 ITcal. min. -1 



= 0.069781 abs. watt 



1 cal.u sec." 1 



= 4.1855 abs. watts 



1 cal.ns min." 1 



= 0.069758 abs. watt 



1 horsepower, electrical, U. S. 

 Brit. 



= 746 abs. watts 



1 horsepower (mechanical) 

 = 550 ft. lb. sec-i 

 = 745.70 abs. watts 



1 horsepower (continental) 

 = 736 abs. watts 



1 cheval-vapeur 



= 75 kg. m. sec. -1 

 = 735.499 abs. watts 



1 Btu min." 1 



= 17.5844 abs. watts 

 = 251.996 ITcal. min." 1 

 = 252.08 cal.is min." 1 



M. Energy per unit area: 



1 langley (ly.) 



= 1 cal.is cm." 1 

 = 4.1855 abs. joules cm."* 

 = 0.011624 Int. kw.-hr. m." 1 

 = 3.6855 Btu ft." 1 



1 abs. joule cm."* 



= 0.23892 cal.« cm." 1 



= 0.00277725 Int. kw.-hr. 



1 Btu ft."* 



= 0.27133 cal.i. cm."' 



= 1.13566 abs. joules cm. 



= 0.88054 Btu ft." 1 

 1 Int. kw.-hr. m." 1 



= 86.028 cal., B cm."* 



= 360.068 abs. joules cm." 



N. Power per unit area: 

 1 cal.is cm." 1 min." 1 

 = 1 ly. min." 1 

 = 0.069758 abs. watt cm." 1 

 = 0.069745 Int. watt cm." 1 

 = 69.745 Int. kw. deka- 



meter' 2 

 = 3.6855 Btu ft." 2 min." 1 

 = 1440 cal.w cm." 1 day" 1 

 = 5307.1 Btu ft." 1 day" 1 



1 Btu ft.' 2 min." 1 



= 0.27133 cal.u cm. -1 min. 

 = 0.0189277 abs. watt cm. 



O. Illumination, brightness, etc.: 



The total luminous flux from a source of unit spherical candlepower is 4n- lumens. 



1 lux (lx.) 1 footcandle (ft.-c.) 



= 1 lumen incident per = 1 lumen incident per 



square meter square foot 



= 0.0001 ph. = 10.76 lx. 

 = 0.09290 ft.-c. 



(continued) 



SMITHSONIAN METEOROLOGICAL TABLES 



