VISCOSITY OF WATER BY THE EFFLUX METHOD. Par 
formula 
oe Mi B 207? 
(36) 
The application of this te to he case in hand gives a = 0-03395, The 
fluidity is therefore 
J’ =1+40-033957 + 0:0002357? (37) 
The values in the final column in the above table of fluidities are 
computed by this formula. With the exception of the values at 
0-5° and 40° they lie between the extremes of the observed values. 
The absolute values of the viscosity at 10° C. deduced from these — 
experiments are! 
Tube A 0013124 
» - C...0°013026 
» D, 0-013010 
» £ 0-013252 
This mean corresponds to the value 1°3628 in the relative fluidity: 
in order to make it agree with the result from the whole of the 
experiments it must be corrected so as to correspond with the 
value 1:3630 of the computed curve. Multiplying therefore by 
the factor 1-3628/1-3630 it becomes 0:013101, and this is the value 
Of 719 best representing the whole of these experiments. The 
mean of the thirty-two determininations at 10° C. in $9 gave 
0013107. Taking the mean of the two we have for the value of 
the viscosity at 0° OC. 
No = 1:3630 x 0-013104 =0-017861 
os and thus ir the general absolute value in C.G.S. units as deduced 
from the whole series of Poiseuille’s observations? we obtain 
Mean 0:013103 
n of a number. The mean of the four 
“ Sutaa oo. 581 of his memoir—a formula 
= 1836-724 (1 + 0-0336793 7 + 0° 9002200086 7?) HD*/L 
hy of remark that, accepting his results as pie vents the 
simple expressio 
q' = 1832'4 a + -0339 + -00022 7) HD*/L 
more exactly expresses them. 
It is aie 
relatively 
4 
4 
: 
‘4 
¢ 
‘a 
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