198 



J. A. POLLOCK. 



The NATURE of the LARGE IONS in the AIR. 



By J. A. Pollock, d. sc, etc 

 Professor of Physics in the University of Sydney. 



[Bead before the Royal Society of N. S. Wales, October 1, 1909.~] 



In a previous paper 1 measures of the mobility of the large 

 ions in the air, for various values of the humidity, were 

 given without discussion as to the form of a possible 

 relationship between the two quantities. Further investi- 

 gation of the properties of these ions has yielded additional 

 results which are collected in Table I, all the observations 

 being reduced to the standard pressure on the assumption 

 mentioned in the former paper. 



Table I. 



>> 



<v a>:£ 



&fl >r& 



831 



> a 2 



«!«3 



l/fc 7 



'"7 6 



X 10 6 



Mean 



*7 6 

 X 10 6 



O 03 



a a> o 

 | %u 



K£ ft 



1908 

 April 7 



Sept. 14 



1909 

 June 4 



18 

 18 

 24 



Aug. 13 

 „ 16 



„ 18 



/ Lusby's \ 2 

 \observations. / 



20-9 



21-3 

 15-3 



16-4 



15-4 



18-2 



16-8 

 15 

 15-9 



235 



772 



770 

 763 



59 

 64 

 65 

 51 



761 



89-5 



761 



85-8 



J? 



757 





759 



768 



92-5 



1 6 V 



jj 





68-0 



2570- 

 2550- 

 2730- 

 2310- 



3350 + 



3140- 

 2980- 

 3120- 



3085 + 

 3360 + 

 3260 + 



389- 

 392- 

 366- 

 433- 



299 + 



318- 

 336- 

 321- 



324 + 

 298 + 

 307 + 



325 



310 + 



367 



3290 



4170 



32900 



6105 



2780 



1710 

 980 

 680 



650 



1120 



900 



1 Pollock, this Journal, p. 61. 2 Lusby, this Journal, p. 55. 



