486     Prof.  Wilson  and  Mr.  Gold  :  Electrical  Conductivity  of 
Gouy  spraver  K,  worked  by  compressed  air,  which  was 
supplied  by  a  rotary  blower  worked  by  a  J-H.P.  motor. 
The  compressed  air  entered  at  H,  and  the  salt  solution  at  N. 
Fio-.  1 
FF.  Flame. 
EE.  Electrodes. 
SS.  Glass  tubes. 
WAV.  Wood  block. 
TT.  Flame-tube. 
B.  Sprayer-bulb. 
K.  Sprayer. 
N.  Solution-tube  and  funnel. 
IIP!'.  Compressed-air  tubes. 
M.  Gas  tube. 
A  A.  Wide  indiarubber  tube.        DD'.  Solution-overflow  tubes. 
The  pressure  of  the  air-supply  was  indicated  by  a  water- 
manometer,  and  was  always  kept  at  the  same  value,  about 
80  cms.  of  water.  The  salt  solution  was  contained  in  a  large 
funnel,  and  its  level  always  kept  a  constant  height  above  the 
sprayer-nozzle.  The  amount  of  gas  entering  the  bulb  was 
measured  by  a  water-meter,  and  its  pressure  kept  constant  by 
means  of  a  regulator;  it  did  not  vary  appreciably. 
The  gas  and  air  supplies  were  so  adjusted  that  a  u  non- 
luminous  "  flame  having  a  sharply-defined  inner  cone  was 
obtained.  This  flame  was  very  steady  in  appearance,  and 
could  be  maintained  constant  for  any  length  of  time 
required. 
The  electrodes  used  in  most  of  the  experiments  consisted 
of  two  concentric  cylinders  made  of  thin  platinum,  of  the 
following  dimensions:  — 
Diameter  of  outside  cylinder  . 
Height 
Diameter  of  inside  cylinder    . 
Height         „  "    „ 
They  were  supported  symmetrically  about  the  axis  of  the 
flame  at  such  a  height  that  the  inner  cone  of  the  flame  just 
reached  up  to  the  level  of  the  lower  ends  of  the  cylinders. 
2*4  cms. 
5-0     „ 
1-2     „ 
