﻿444 
  Mr. 
  Mallet 
  on 
  the 
  Mechanism 
  of 
  Stromboli. 
  [May 
  27, 
  

  

  had 
  ruptured, 
  aud 
  haemorrhage 
  had 
  taken 
  place 
  into 
  the 
  decidua 
  ; 
  in 
  one 
  case 
  

   only, 
  in 
  which 
  bleeding 
  had 
  not 
  begun, 
  had 
  a 
  Graafian 
  follicle 
  been 
  rup- 
  

   tured. 
  The 
  latter 
  statement 
  appears 
  opposed 
  to 
  the 
  conclusions 
  at 
  which 
  

   I 
  have 
  arrived 
  ; 
  but 
  this 
  is 
  only 
  apparent 
  ; 
  for 
  in 
  one 
  case 
  a 
  follicle 
  had 
  

   ruptured, 
  in 
  four 
  a 
  Graafian 
  follicle 
  had 
  matured 
  before 
  haemorrhage 
  began, 
  

   and 
  in 
  one 
  of 
  these 
  rupture 
  was 
  on 
  the 
  eve 
  of 
  takiug 
  place 
  ; 
  in 
  eighteen 
  

   a 
  follicle 
  had 
  ruptured, 
  and 
  haemorrhage 
  had 
  taken 
  place 
  into 
  the 
  decidua 
  

   menstrualis. 
  Put 
  in 
  this 
  form, 
  Reichert's 
  cases 
  are 
  not 
  opposed 
  to 
  the 
  

   conclusions 
  arrived 
  at 
  in 
  the 
  preceding 
  note 
  ; 
  and 
  as 
  his 
  cases 
  have 
  not 
  

   been 
  described, 
  it 
  is 
  not 
  possible 
  to 
  say 
  what 
  their 
  actual 
  bearing 
  may 
  be. 
  

   The 
  conclusion 
  arrived 
  at 
  by 
  E-eichert, 
  after 
  examination 
  of 
  the 
  23 
  speci- 
  

   mens, 
  however, 
  is 
  that 
  rupture 
  of 
  the 
  Graafian 
  follicle 
  takes 
  place 
  at 
  an 
  

   early 
  stage 
  of 
  the 
  menstrual 
  flow. 
  

  

  IV. 
  " 
  Note 
  on 
  Mr. 
  Mallet's 
  Paper 
  on 
  the 
  Mechanism 
  of 
  Strom- 
  

   boli"*. 
  By 
  Robert 
  Mallet, 
  F.R.S. 
  Received 
  May 
  21, 
  1875. 
  

  

  Since 
  the 
  appearance 
  of 
  my 
  paper 
  on 
  Stromboli 
  some 
  strictures 
  hostile 
  

   to 
  the 
  views 
  therein 
  contained 
  have 
  been 
  publishedt, 
  in 
  which 
  it 
  is 
  urged 
  

   that 
  the 
  elevation 
  of 
  the 
  fundus, 
  or 
  bottom 
  of 
  the 
  visible 
  crater, 
  which 
  

   I 
  have 
  assumed 
  at 
  300 
  to 
  400 
  feet 
  above 
  the 
  sea, 
  is 
  greatly 
  below 
  the 
  

   truth, 
  that 
  being, 
  it 
  is 
  affirmed, 
  at 
  least 
  2000 
  feet 
  above 
  the 
  sea-level. 
  It 
  is 
  

   added 
  that 
  " 
  Mr. 
  Mallet's 
  whole 
  theory 
  hangs 
  upon 
  the 
  proximity 
  of 
  the 
  

   bottom 
  of 
  the 
  crater 
  to 
  the 
  sea-level," 
  and 
  that 
  "Mr. 
  Mallet's 
  hypothesis 
  

   of 
  the 
  mechanism 
  of 
  Stromboli 
  is 
  based 
  entirely 
  on 
  these 
  grossly 
  inac- 
  

   curate 
  measurements." 
  It 
  is 
  unnecessary 
  that 
  I 
  should 
  occupy 
  the 
  time 
  

   of 
  the 
  Society 
  by 
  any 
  discussion 
  as 
  to 
  the 
  correctness 
  or 
  incorrectness 
  of 
  

   either 
  of 
  the 
  above 
  levels, 
  neither 
  of 
  which 
  are 
  more 
  than 
  loose 
  approxi- 
  

   mations 
  ; 
  but 
  I 
  beg 
  permission 
  to 
  point 
  out 
  that 
  the 
  theory 
  of 
  the 
  rhyth- 
  

   mical 
  action 
  of 
  Stromboli 
  which 
  I 
  have 
  proposed 
  does 
  not 
  rest 
  upon 
  the 
  

   proximity 
  of 
  the 
  fundus 
  to 
  the 
  sea-level, 
  and 
  stands 
  equally 
  valid 
  whether 
  

   the 
  height 
  of 
  the 
  tube 
  C 
  (see 
  diagram 
  no. 
  4, 
  p. 
  512, 
  Proc. 
  Roy. 
  Soc. 
  

   1874), 
  or, 
  what 
  is 
  the 
  same 
  thing, 
  the 
  difference 
  in 
  level 
  between 
  the 
  sea 
  

   and 
  the 
  bottom 
  of 
  the 
  crater, 
  be 
  300 
  to 
  400 
  feet 
  or 
  2000 
  feet. 
  That 
  

   tube, 
  whether 
  long 
  or 
  short, 
  is 
  never 
  filled, 
  according 
  to 
  my 
  views, 
  by 
  a 
  

   column 
  of 
  liquid 
  lava 
  or 
  water, 
  but 
  only 
  with 
  steam 
  more 
  or 
  less 
  dense 
  

   before 
  being 
  blown 
  off: 
  to 
  a 
  lower 
  pressure 
  ; 
  and 
  the 
  only 
  change 
  intro- 
  

   duced 
  by 
  lengthening 
  the 
  tube 
  C 
  is, 
  that 
  a 
  greater 
  volume 
  of 
  steam 
  is 
  

   required 
  to 
  fill 
  it 
  ; 
  so 
  that 
  the 
  tube 
  being 
  supposed 
  of 
  uniform 
  calibre, 
  the 
  

   volume 
  of 
  steam 
  required 
  to 
  produce 
  equal 
  tensions 
  in 
  the 
  shorter 
  or 
  

   longer 
  tube, 
  as 
  above 
  stated, 
  would 
  be 
  about 
  as 
  one 
  to 
  five 
  ; 
  and 
  no 
  diffi- 
  

   culty 
  can 
  suggest 
  itself 
  to 
  the 
  mind 
  of 
  any 
  physicist 
  as 
  to 
  the 
  adequacy 
  

   of 
  the 
  mechanism 
  that 
  I 
  have 
  suggested 
  for 
  such 
  supply. 
  

  

  * 
  Proc. 
  Eoy. 
  Soc. 
  1874, 
  vol. 
  xxii. 
  p. 
  496. 
  

   t 
  Geol. 
  Mag., 
  Dec. 
  1874 
  and 
  May 
  1875. 
  

  

  