508 



Mr. R. Hoskine-- on th 



Typical Observations with Tube IV. in Glischrometer. 



Temp. 



Manometer | 



Temp, of 



Time of 



Bulb 



phT 



1 

 T' 



Reading (h) 



Manometer , Flow (T)l 



being- 



(reduced to 



cms. 



° C. 



sees. 1 



emptied. 



50°) X 10-3. 



f 50-10 



*108'08 



26-7 



61-26 



R 



6-614 



•01632 



J 50-10 



108-10 



„ 



60-80 



L 



6-561 



•01645 



1 50-10 



108-09 



»> 



61-83 



R 



6-675 



•01617 ! 



(.50-10 



108-10 



j? 



61-21 



L 



6-607 



•01634 



f 50-04 

 1 50-01 



150-97 



26-7 



46-49 



R 



6-995 



•02151 



151-07 



J5 



46-30 



L 



6-967 



•02160 



| 50-00 

 1 50-00 



150-96 



5J 



46-50 



R 



6-990 



•02150 



150-96 



■a 



46-30 



L 



7-955 



02160 



f 50-00 



197-17 



260 



37-44 



R 



7-348 



•02671 



J 50-00 



197-07 



J} 



37-35 



L 



7-326 



•02671 ! 



1 50-00 



197'04 



„ 



37-54 



R 



7-359 



•02664 



[50-00 



196-98 



j> 



37-37 



L 



7-326 



02677 



f 50-10 

 J 50-10 



f20-92 



25-7 



28-25 



R 



8-023 



•03539 



20-96 



}J 



28-00 



L 



7-998 



■03571 ! 



1 50-10 

 [50-10 



20-92 



}) 



28-32 



R 



8-042 



•03531 



20-92 



ff 



28-10 



L 



7-980 



•03559 1 



f 50-10 



30-98 



25-7 



21-30 



R 



8 954 



•04698 



J 50-10 



30-99 





22-80 



L 



9-594 



•04386 



1 50-10 



31-00 



5) 



21-40 



R 



9010 



•04671 



[50-10 



31-00 





22-58 



L 



9-498 



•04429 



f 50-00 



40-47 



25-V 



20-78 



R 



11-378 



•04812 



j 50-00 

 1 50-00 



40-47 



,, 



21-33 



L 



11-682 



•04688 



40-47 



}> 



20-43 



R 



11-185 



•04895 



[50-00 



40-47 



>j 



21-05 



L 



11-530 



•04750 



* Water Manometer. 



f Mercury Manometer. 



The numbers in columns 6 and 7 were used to obtain the 

 curves given in figs. 2, 3, 4, & 5 (PL XIII.). It will be noticed 

 that for a considerable distance the lines are straight, indi- 

 cating constant values for c in equation (2), and therefore for 

 m for the particular capillary. This constancy is remarkable 

 when we consider the enormous speed with which the water 

 is forced through the tubes in many cases. The individual 

 observations show also that there is no variation in any par- 

 ticular case, and that the value of m in the general formula 

 can be relied upon, when determined in this way. There is, 

 therefore, no necessity to keep the kinetic energy correction 

 small in comparison with the first term in determining 

 viscosities by the efflux method, provided, of course, that the 

 time of flow and pressure can be measured with sufficient 

 accuracy. This will be shown later, where values have been 

 worked out. In certain curves it will also be noticed that at 

 a particular point, there is an abrupt change in the direction of 

 the line, indicating either a largely increased value for m, or a 

 change in the nature of the flow. This is most marked in both 

 the curves for Tube IY. and in one of the curves for Tube III. 



The following values for C and c in equation (2) were 



