446 
MESSRS, T. B. THORPE AND J. W. RODGER ON THE RELATIONS 
The results of the viscosity observations between 0° and 8°, by taking 
=z 0°-37 ^3 = 7°-41 — 3°-79 
>^^=•017570 7^3 = -014006 = -015687, 
may be represented by the formula 
58-7375 
~~ (58-112 + 0™ ’ 
which gives results in fair accord with the observed values. 
Mean temp. 
'/• 
Difference. 
Observed (mean). 
Calculated. 
o 
0-37 
-01757 
-01757 
•00000 
1-13 
-01710 
-01712 
+ -00002 
1-86 
-01670 
-01671 
+ -00001 
2-41 
-01640 
-01641 
+ -00001 
3-09 
-01608 
-01605 
- -00003 
3-84 
-01568 
-01566 
- -00002 
4-47 
-01535 
-01535 
•00000 
5-19 
-01500 
-01500 
•00000 
5-94 
-01464 
-01465 
+ -00001 
6-67 
-01433 
-01433 
•00000 
7-41 
-01401 
-01401 
•00000 
8-01 
-01377 
•01375 
- -00002 
The curve representing the change in viscosity was originally plotted on as large a 
scale as was consistent with the accuracy of the observations, but no indication was 
given by this curve that any anomalous change occurred in the viscosity at 
temperatures between 0 ° and 8 °. It must be borne in mind, however, that the 
anomalous change in the density of water amounts only to about 1 part in 10,000 ; 
hence, since the accuracy attained in these special observations of viscosity probably 
does not exceed 1 in 5,000, it mav be doubted whether any anomalous change in 
viscosity of the same order of magnitude as that observed in the case of the density 
would be detected by any of our present experimental methods. 
Measurements of the viscosity of water by the tube method have been made 
by the following observers ;— 
PoiSEUiLLE.‘ Mem. des Sav. Etrang.,’ 9, 433 (184(i) 
Graham .‘Phil. Trans.,’ 151, 373 (1861). 
Pellstab. ‘ Inaug. Uiss. Bonn.’ (1868). 
Sprung .‘-Pogg. Ann.’ L59, 1 (1876). 
Bosencranz (comm, by 0. E. Meyer) . ‘ Wied. Ann.,’ 2, 387 (1877). 
Grotrian .‘ Wied. Ann.,’ 8 , 536 (1879). 
