﻿Flutings 
  in 
  a 
  Sound-Ware. 
  479 
  

  

  diameter 
  rotated 
  as 
  a 
  single 
  body 
  until 
  their 
  line 
  of 
  centres 
  

   was 
  transverse 
  to 
  the 
  stream-lines. 
  

  

  The 
  roughness 
  and 
  shape 
  of 
  the 
  bottom 
  of 
  the 
  tube 
  inter- 
  

   fered 
  somewhat 
  with 
  the 
  best 
  observation. 
  To 
  overcome 
  

   this 
  difficulty 
  a 
  plane 
  piece 
  of 
  plate-glass 
  was 
  fringed 
  with 
  

   paper, 
  to 
  prevent 
  the 
  spheres 
  from 
  rolling 
  off, 
  and 
  placed 
  in 
  

   the 
  tube. 
  The 
  spheres 
  resting 
  on 
  the 
  surface 
  of 
  the 
  glass 
  

   readily 
  formed 
  flutings 
  across 
  its 
  plane 
  surface, 
  but 
  by 
  

   slightly 
  tilting 
  the 
  glass 
  surface 
  the 
  spheres 
  could 
  be 
  made 
  

   to 
  roll 
  from 
  side 
  to 
  side 
  where 
  flutings 
  would 
  be 
  formed 
  

   projecting 
  somewhat 
  up 
  the 
  incline. 
  With 
  this 
  arrangement 
  

   of 
  the 
  apparatus 
  the 
  following 
  observations 
  were 
  determined:— 
  

  

  2. 
  Observations 
  on 
  a 
  Plane 
  Surface. 
  

  

  (1) 
  Observations 
  (1) 
  and 
  (2) 
  of 
  the 
  previous 
  section 
  were 
  

   verified. 
  

  

  (2) 
  Two 
  spheres 
  with 
  line 
  of 
  centres 
  transverse 
  to 
  stream- 
  

   lines 
  were 
  attracted 
  and 
  then 
  repelled 
  to 
  a 
  distance 
  of 
  about 
  

   half 
  their 
  diameter, 
  and 
  remained 
  thus 
  while 
  moving 
  forward 
  

   and 
  back 
  on 
  the 
  glass. 
  

  

  (3) 
  Three 
  spheres 
  situated 
  as 
  in 
  (2) 
  acted 
  in 
  all 
  respects 
  

   like 
  two 
  spheres. 
  

  

  (4) 
  The 
  surface 
  of 
  the 
  glass 
  plate 
  was 
  inclined 
  at 
  an 
  angle 
  

   of 
  about 
  20° 
  to 
  the 
  horizontal. 
  One 
  sphere 
  was 
  resting 
  

   against 
  the 
  side 
  of 
  the 
  tube, 
  another 
  was 
  in 
  contact 
  with 
  it, 
  

   resting 
  on 
  the 
  inclined 
  plate. 
  Their 
  line 
  of 
  centres 
  was 
  

   transverse 
  to 
  the 
  stream-lines. 
  When 
  the 
  sound-wave 
  was 
  

   present 
  the 
  second 
  sphere 
  was 
  repelled 
  to 
  a 
  distance 
  of 
  about 
  

   half 
  its 
  diameter 
  up 
  the 
  incline 
  from 
  the 
  first, 
  and 
  maintained 
  

   that 
  position 
  during 
  the 
  duration 
  of 
  the 
  sound-wave, 
  then 
  

   returned 
  to 
  its 
  .original 
  position. 
  Three 
  spheres 
  in 
  line 
  acted 
  

   in 
  a 
  similar 
  manner. 
  

  

  (5) 
  Grlass 
  plate 
  as 
  in 
  (4). 
  First 
  sphere 
  fixed 
  to 
  upper 
  

   side 
  of 
  plane 
  surface. 
  The 
  two 
  spheres 
  in 
  relatively 
  the 
  same 
  

   position 
  as 
  in 
  (4). 
  When 
  the 
  sound-wave 
  ceased 
  the 
  second 
  

   sphere 
  would 
  start 
  to 
  roll 
  down 
  the 
  inclined 
  surface 
  from 
  the 
  

   first 
  sphere, 
  but 
  as 
  soon 
  as 
  the 
  sound-wave 
  was 
  again 
  started 
  

   this 
  sphere 
  was 
  attracted 
  up 
  the 
  inclined 
  plane 
  to 
  within 
  a 
  

   distance 
  of 
  about 
  half 
  its 
  diameter, 
  where 
  it 
  was 
  maintained 
  

   during 
  the 
  maintenance 
  of 
  the 
  sound-wave. 
  

  

  Although 
  the 
  sealing-wax 
  spheres 
  seemed 
  to 
  move 
  with 
  

   perfect 
  freedom 
  on 
  the 
  surface 
  of 
  the 
  plate-glass, 
  and 
  there 
  

   seemed 
  to 
  be 
  nothing 
  that 
  could 
  possibly 
  vitiate 
  the 
  results 
  

   obtained, 
  yet 
  the 
  question 
  of 
  possible 
  surface-conditions 
  arose, 
  

   and 
  it 
  was 
  decided 
  to 
  suspend 
  these 
  same 
  spheres 
  in 
  the 
  

   centre 
  of 
  the 
  tube. 
  

  

  2K2 
  

  

  