138 THE ROYAL SOCIETY OF CANADA 



the strip of glass as well as on the tube. For the salt solution all the 

 ripples had the same advance, but in the case of water the inner 

 ripple of the small tube was shorter than the others. 



A battery of tubes of various diameters was fitted up so that the 

 ripple in each- tube was under the same conditions. The diameters 

 of the tubes varied from • 6 to 3 cm. For the strong salt solution the 

 advance of the ripple was the same in each case but for water there was 

 a slight variation. 



From the graphs on Figs. 4 and 6, it is shown that the advance of 

 the ripple decreases with an increase of velocity. For the faster velo- 

 cities, the ripple is more distant and a better definition of it was 

 obtained on the photographic plate; hence, it appears that the ripple 

 has a greater thickness, or tends to heap up for the faster velocities. 

 It is further shown in Fig. 6 that the advance of the ripple varies as 

 the specific gravity of the solution varies. 



From the graph in Fig. 5, it is shown that the time given to the 

 tube to drain, effects the advance of the ripple, such that it increases 

 as the time to drain is increased, but the relation between the two 

 has not yet been arrived at, but it seems likely that the advance of 

 the ripple depends on the thickness of liquid clinging to the walls of 

 the tube. 



The work is still in progress and it is hoped that, with the intro- 

 duction of more refined methods of measurement, the knowledge of 

 the conditions attending this ripple will be greatly advanced. 



This work was carried out under the direction of Dr. John Satterly. 



