Canon Moseley on the steady Flow of a Liquid. 353 



the direction D E C, as shown by the arrows in the tube and the 

 air-bubble. 



Fig. 1. 



In all streams there cannot but be a tendency in the water 

 to transfer itself from the sides, where the motion is slower and 

 the pressure greater (as shown by equation 19), to the centre, 

 where the motion is quicker and the pressure consequently less 

 — and also to rise from the bottom to the surface, carrying up 

 with it the mud. 



The velocity of the central filament in a horizontal pipe. 



The internal surface of the pipe resists the motion over it of 

 the film of liquid which is in contact with it ; that film resists 

 the motion over it of the next film ; that of the next, and so on 

 to the central filament. Let ACDca (fig. 2) represent a lon- 



Fio:. 2. 



DC 



-V 



t 



-zk 



gitudinal section, through the axis, <of the liquid flowing unr 

 Phil. Mag. S. 4. Vol. 42. No. 281. Nov. 1871. 2 A 



