﻿476 
  

  

  Prof. 
  S. 
  E. 
  Cook 
  on 
  

  

  The 
  last 
  column 
  of 
  this 
  table 
  indicates 
  that 
  for 
  a 
  given 
  

   medium 
  and 
  fluting 
  material 
  there 
  may 
  exist 
  a 
  direct 
  ratio 
  

   between 
  the 
  distance 
  apart 
  of 
  the 
  flutings 
  and 
  the 
  mean 
  free 
  

   path 
  of 
  the 
  molecule. 
  

  

  Brief 
  studies 
  on 
  flu 
  tings 
  are 
  here 
  presented 
  on 
  account 
  of 
  

   their 
  peculiar 
  interest 
  in 
  acoustic 
  attractions 
  and 
  repulsions. 
  

  

  . 
  5. 
  Flirtings 
  produced 
  by 
  a 
  direct 
  sound-ivave. 
  — 
  A 
  plane 
  glass 
  

   plate 
  was 
  substituted 
  for 
  the 
  Kundt 
  tube. 
  The 
  vibrating 
  

   cork 
  was 
  cut 
  by 
  a 
  horizontal 
  plane 
  and 
  the 
  plate 
  was 
  placed 
  

   about 
  one 
  millimetre 
  below. 
  When 
  the 
  bar 
  was 
  clamped 
  for 
  

   its 
  fourth 
  overtone 
  flutings 
  of 
  amorphous 
  silica 
  were 
  produced 
  

   on 
  the 
  plate. 
  These 
  flutings 
  were 
  elliptical 
  in 
  form, 
  having 
  

   for 
  their 
  common 
  axis 
  the 
  line 
  between 
  the 
  vibrating 
  cork 
  

   and 
  the 
  glass 
  plate 
  (fig. 
  1). 
  Flutings 
  were 
  also 
  produced 
  

  

  Ficr, 
  1. 
  

  

  when 
  the 
  bar 
  was 
  clamped 
  perpendicularly 
  and 
  the 
  glass 
  plate 
  

   placed 
  within 
  a 
  centimetre 
  of 
  the 
  cork. 
  These 
  flutings 
  were 
  

   concentric 
  circles 
  around 
  the 
  cork 
  (fig. 
  2). 
  

  

  6. 
  The 
  vibration 
  of 
  'laminae. 
  — 
  A 
  mica 
  disk 
  was 
  threaded 
  on 
  

   a 
  fine 
  wire 
  stretched 
  through 
  the 
  centre 
  of 
  the 
  Kundt 
  tube. 
  

   A 
  cork 
  was 
  fastened 
  to 
  one 
  prong 
  of 
  a 
  large 
  tuning-fork 
  — 
  

   frequency 
  32 
  per 
  second 
  — 
  and 
  placed 
  in 
  the 
  end 
  of 
  the 
  Kundt 
  

   tube. 
  The 
  cork 
  was 
  thus 
  made 
  to 
  vibrate 
  in 
  unison 
  with 
  the 
  

   prong 
  of 
  the 
  tuning-fork. 
  The 
  mica 
  disk, 
  though 
  in 
  no 
  way 
  

   connected 
  to 
  the 
  cork, 
  vibrated 
  in 
  unison 
  with 
  it. 
  The 
  

   amplitude 
  of 
  the 
  vibration 
  of 
  the 
  cork 
  w 
  T 
  as 
  from 
  one 
  to 
  two 
  

   centimetres. 
  That 
  of 
  the 
  mica 
  disk 
  was 
  less. 
  

  

  This 
  experiment 
  suggests 
  that 
  the 
  laminse 
  might 
  vibrate 
  in 
  

   unison 
  with 
  the 
  vibrating 
  bar. 
  In 
  order 
  to 
  examine 
  this, 
  a 
  

   glass 
  tube 
  was 
  split 
  longitudinally, 
  the 
  edges 
  were 
  ground 
  

   smooth, 
  and 
  the 
  opening 
  was 
  overlaid 
  with 
  cover-glasses 
  

  

  