164 



TABLE 159. 



VISCOSITY OF GASES AND VAPORS- 

 The values of /A given in the table are io 6 times the coefficients of viscosity in C. G. S. units. 



* Gilchrist's value of the viscosity of air may be taken as the most accurate at present avail- 

 able. His value at 20.2 C is 1.812 x io~ 4 . The temperature variation given by Holman (Phil. 

 Mag. 1886) gives p = 1715.50 x io~ 7 (i + .oo275/ - .00000034/2). See Phys. Rev. i, 1913. 

 MilHkan (Ann. Phys. 41, 759, 1913) gives for the most accurate value f* t = 0.00018240 - 

 0.000000493(23-0 when (23>*>i2) whence ju 20 = 0.0001809 0.1%. For // he gives 

 0.0001711. 



fThe values here given were calculated from Koch's table (Wied. Ann. 19, p. 869, 1883) 

 by the formula /z = 489 [i 4- 746(/ 270)]. 



SMITHSONIAN TABLES. 



