334 



Mr. H. S. Allen on the Motion of 



Table II. 

 Air-bubbles in Water. 



No. of 





Kadi us 



Observation. 



Temp. 



in cm. 





°0. 





14. 



86 



•00471 * 



16. 



8-5 



■00570 



9. 



8-4 



•00632 



8. 



8-4 



•00719 



11. 



8-5 



•0097 



13. 



8-6 



•0106 



15. 



85 



•0109 1 



10. 



8-5 



•0141 



12. 



8-6 



■0144 * 



7. 



8-4 



•0155 



1. 



7-6 



•0170 



5. 



8-4 



•0187 



17. 



8-4 



•0190 



4. 



83 



•0201 



6. 



84 



•0206 



18. 



8-4 



■0224 



3. 



7-9 



•0241 



2. 



7-8 



•0305 



Velocity in cm. /sec. 



Calculated 8°-4C. 

 Observed. 



•387 

 •511 

 •585 

 •626 

 1-26 

 1-40 

 1-45 

 2-03 

 2-18 

 2-36 

 2-67 

 313 

 3-20 

 3-39 

 3-35 

 3-89 

 423 

 554 



Parabolic Linear 

 Formula. Formuk 



•345 



•505 

 •620 

 •802 

 1-46 

 1-75 



•16 

 •37 

 •50 

 ■68 

 1-22 

 1-41 

 146 

 213 

 2-21 

 242 

 273 

 3-09 

 3-15 

 3-38 

 347 

 3-85 

 419 

 5-49 



Although considerable time was spent in the endeavour to 

 penetrate further into the region of non-sinuous flow the 

 small value of the critical radius in the case of water made it 

 difficult to obtain results that were entirely satisfactory. It 

 was therefore decided to employ a more viscous liquid for 

 which the critical radius would have a greater value. For 

 this purpose aniline was selected. Its coefficient of viscosity, 

 as determined by Wijkander f at 12° C, is "06023 (about five 

 times that of water at the same temperature) and its specific 

 gravity (%) is 1/038. The critical radius calculated from 

 these values is "0255 centim. 



The experiments were carried out in the same manner as in 

 the case of water. The numerical results are given in 

 Table III. 



* Group of three equal bubbles. 



t ,, two „ ,, 



t Wied. Beibl. vii. p. 11 (1879). 



