﻿34 
  EaMns 
  — 
  Analyses 
  of 
  Astrophyllite 
  and 
  Tscheffkinite. 
  

  

  From 
  these 
  121 
  theoretical 
  diameters 
  for 
  each 
  scale 
  a 
  consec- 
  

   utive 
  series 
  to 
  be 
  chosen 
  for 
  each 
  stop. 
  He 
  finds 
  in 
  practice 
  

   that 
  for 
  a 
  large 
  number 
  of 
  stops 
  the 
  first 
  ratio 
  is 
  suitable 
  ; 
  for 
  

   an 
  ordinary 
  Principal 
  c' 
  should 
  have 
  the 
  diameter 
  of 
  No. 
  62 
  ; 
  

   for 
  a 
  Wide 
  Principal, 
  No. 
  58 
  is 
  suitable. 
  But 
  for 
  many 
  stops 
  

   this 
  ratio 
  is 
  not 
  satisfactory 
  ; 
  the 
  tone 
  must 
  be 
  fuller 
  in 
  the 
  

   upper 
  parts 
  ; 
  for 
  a 
  given 
  list 
  of 
  stops 
  the 
  ratio 
  1 
  : 
  2*67 
  is 
  better 
  ; 
  

   the 
  diameter 
  of 
  c' 
  ranges 
  between 
  No. 
  55 
  for 
  the 
  Wide 
  Princi- 
  

   pal 
  Bass, 
  and 
  No. 
  77 
  for 
  the 
  Yiola 
  d'Amour. 
  For 
  the 
  Pedal 
  

   stops 
  and 
  some 
  others 
  he 
  advises 
  the 
  ratio 
  1:25, 
  

  

  This 
  is 
  a 
  very 
  brief 
  summary 
  of 
  the 
  portions 
  of 
  Topfer's 
  

   voluminous 
  work 
  that 
  relate 
  to 
  the 
  physical 
  side 
  of 
  organ 
  

   building. 
  It 
  does 
  not 
  appear 
  that 
  the 
  questions 
  involved 
  have 
  

   been 
  thought 
  out 
  from 
  the 
  standpoint 
  of 
  the 
  physicist, 
  or 
  that 
  

   the 
  author's 
  views 
  are 
  entirely 
  consistent. 
  Mr. 
  Bosanquet 
  

   credits 
  to 
  Topfer 
  the 
  law 
  that 
  the 
  quantities 
  of 
  wind 
  belong- 
  

   ing 
  to 
  the 
  same 
  stop 
  vary 
  as 
  the 
  lengths 
  of 
  the 
  pipes. 
  I 
  have 
  

   not 
  been 
  able 
  to 
  find 
  any 
  statement 
  to 
  this 
  effect 
  more 
  definite 
  

   than 
  the 
  one 
  already 
  quoted 
  from 
  p. 
  153-4, 
  that 
  the 
  quantities 
  

   of 
  wind 
  used 
  are 
  nearly 
  as 
  1 
  : 
  2 
  for 
  the 
  8ve, 
  sometimes 
  more, 
  

   sometimes 
  less 
  ; 
  but 
  on 
  p. 
  200 
  he 
  gives 
  the 
  theoretical 
  quanti- 
  

   ties 
  for 
  the 
  successive 
  C's 
  through 
  9 
  octaves, 
  and 
  the 
  ratio 
  for 
  

   the 
  8ve 
  I 
  find 
  to 
  be 
  1 
  : 
  1*99. 
  But 
  on 
  the 
  other 
  hand 
  he 
  states 
  

   positively, 
  as 
  already 
  quoted, 
  that 
  the 
  quantity 
  of 
  wind 
  must 
  

   be 
  as 
  1 
  : 
  y/S 
  for 
  the 
  8ve; 
  that 
  is, 
  as 
  the 
  sections 
  of 
  the 
  pipes 
  

   in 
  his 
  first 
  " 
  normal 
  scale." 
  In 
  other 
  words, 
  his 
  most 
  definite 
  

   statement 
  makes 
  the 
  quantities 
  for 
  the 
  8ve 
  as 
  1:^/8; 
  his 
  

   alleged 
  law 
  and 
  Mr. 
  Bosanquet's 
  experiments 
  give 
  the 
  ratio 
  

   1:^/8, 
  and 
  my 
  experiments 
  give 
  the 
  ratio 
  1:^/8; 
  these 
  

   ratios 
  are 
  as 
  1 
  : 
  {V 
  64, 
  {V16, 
  {VS. 
  While 
  it 
  is 
  unsafe 
  to 
  dogma- 
  

   tize 
  on 
  a 
  matter 
  that 
  must 
  vary 
  according 
  to 
  the 
  circumstances 
  

   of 
  the 
  case, 
  the 
  character 
  of 
  the 
  stop, 
  the 
  location 
  of 
  the 
  pipes, 
  

   the 
  size 
  of 
  the 
  hall 
  where 
  they 
  are 
  to 
  sound, 
  the 
  judgment 
  of 
  

   the 
  finisher, 
  etc., 
  etc., 
  I 
  have 
  no 
  hesitation 
  in 
  expressing 
  my 
  

   belief 
  that 
  the 
  last 
  ratio, 
  or 
  one 
  still 
  nearer 
  unity, 
  will 
  usually 
  

   be 
  found 
  nearer 
  the 
  truth 
  than 
  either 
  of 
  the 
  others. 
  

  

  Feb., 
  1891. 
  

  

  Art. 
  IY. 
  — 
  New 
  Analyses 
  of 
  Astrophyllite 
  and 
  Tscheff- 
  

   kinite 
  ; 
  by 
  L. 
  G. 
  Eakins. 
  

  

  I. 
  Astrophyllite. 
  

   Near 
  the 
  noted 
  cryolite 
  locality 
  at 
  St. 
  Peters 
  dome 
  in 
  the 
  

   Pike's 
  Peak 
  region 
  of 
  Colorado, 
  there 
  was 
  found 
  some 
  years 
  

   ago 
  an 
  unusually 
  fine 
  lot 
  of 
  astrophyllite, 
  and 
  in 
  such 
  a 
  pure 
  

  

  