VISCOSITY OF WATER BY THE EFFLUX METHOD. 125 
Corrected times of efflux (seconds ). 
Temp. C. Tube A. Tube C. Tube Di. Tube £. 
0: *2308°7  *2848-7 $3409°7 *2735°8 
0:5 2327:0 2809-2 2697°3 
5 2014-6 2416°1 2894°1 2314°6 
10 1739°7 2087°5 2501°3 2000-7 
15 1518-2 1830-2 2191-0 1751-4 
20 1337°0 1607°9 1923-0 1542-0 
25 1186°7 1427-6 1713-2 13718 
30 1061-2 1279-7 1531:°0 1227°1 
35 954-1 1148°5 1374°3 1101°8 
40 862°3 1041°3 1243°8 998-4 
45 782-2 947-4 1136°9 906°8 
It happens, somewhat curiously, that if we take the reciprocals 
of the efflux times their progression may be represented with 
considerable exactitude by a curve of the second degree. Simplicity 
_ of treatment, and a convenient comparison of the results obtained 
from each tube, may be simultaneously secured by expressing the 
fluidity for 0° C. as unity. We therefore divide the efflux times 
for 0° by those for the other temperatures, the quotients so obtained 
are entered in the following table. 
two he value for 0° C. marked + is the mean determined by 
... (a) and (b) the results differing, it happens, only 0-2 second. 
iia od (a) was extrapolation through the points determined by the 
efflux 8 sees oy, 15 and 20. The method (b) was:—the sum of the 
the ha sat 0° for tubes A, C and E divided by the similar sum for 
the OT between the limits 5° to 45° inclusive, was multiplied into 
this ext ciara ve the times for tube D,. In regard to the legitimacy of 
extrapolation see § 25 hereafter. 
2 ig ; 
Pm fluidity / has already been defined, § 3, as the reciprocal of the 
constary,, the Pelative fluidity f’ will therefore be 1/1 multiplied by some 
