﻿Notations 
  employed 
  in 
  Theories 
  of 
  Crystal- 
  structure. 
  207 
  

  

  The 
  work 
  of 
  drawing 
  up 
  the 
  tables 
  has 
  led 
  Hie 
  to 
  the 
  con- 
  

   clusion 
  that 
  the 
  number 
  of 
  possible 
  groups 
  of 
  movements 
  

   which 
  contain 
  3 
  independent 
  translations 
  which 
  are 
  not 
  

   infinitesimal, 
  is 
  really 
  230. 
  

  

  Notes. 
  — 
  Sohncke's 
  groups 
  9 
  and 
  13 
  are 
  identical, 
  as 
  

   Schoen 
  flies 
  pointed 
  out. 
  

  

  Fedorow 
  gives 
  * 
  44,?=rD\ 
  45 
  s 
  = 
  D*, 
  70a 
  = 
  jf> 
  71 
  a 
  = 
  J)\ 
  

  

  & 
  3 
  3' 
  3 
  3 
  T 
  

  

  TV 
  4 
  6 
  

  

  72« 
  = 
  D 
  73a 
  = 
  D 
  , 
  in 
  his 
  table 
  o£ 
  his 
  own 
  and 
  Schoen 
  flies' 
  

  

  results. 
  That 
  this 
  is 
  wrong 
  appears 
  from 
  his 
  own 
  words 
  on 
  

   p. 
  228 
  of 
  the 
  Zeitschr. 
  f. 
  Kryst. 
  u. 
  Min. 
  xxiv. 
  Similarly 
  he 
  has 
  

  

  wrongly 
  compared 
  55 
  6 
  = 
  D 
  OJ 
  , 
  56 
  s=D 
  OJ 
  , 
  45A=D^ 
  46 
  h 
  — 
  

  

  3d 
  3d 
  oft 
  

  

  K 
  i7s 
  =K> 
  48 
  *= 
  D 
  L> 
  «*-dL 
  43A 
  =<- 
  

  

  A 
  • 
  1 
  4 
  ^ 
  8 
  

  

  Again, 
  he 
  gives 
  in 
  the 
  same 
  place 
  44a 
  = 
  D 
  45a=D> 
  

  

  3 
  7 
  

  

  48a 
  = 
  D 
  4 
  , 
  49a 
  = 
  D 
  ; 
  which 
  is 
  incorrect 
  as 
  appears 
  from_ 
  

  

  p. 
  229 
  of 
  the 
  Zeitschr. 
  f. 
  Kryst. 
  u. 
  Min. 
  xxiv., 
  and 
  from 
  

   Table 
  V. 
  at 
  the 
  end 
  of 
  the 
  same 
  volume. 
  

  

  In 
  Barlow's 
  tablet 
  there 
  is 
  a 
  small 
  error; 
  there 
  he 
  says 
  

   that 
  58 
  B 
  1} 
  58 
  B 
  2 
  , 
  58 
  B 
  3 
  are 
  of 
  type 
  62 
  (3 
  of 
  Sohncke), 
  so 
  

   specialized 
  that 
  its 
  axes 
  lie 
  as 
  those 
  of 
  the 
  type 
  58 
  or 
  60' 
  

   (11 
  or 
  10 
  of 
  Sohncke) 
  ; 
  now 
  these 
  two 
  last 
  groups, 
  which 
  are' 
  

   V 
  9 
  and 
  V 
  8 
  of 
  Schoenflies, 
  belong 
  to 
  Schoenflies' 
  RaumgiUer 
  

   IY" 
  and 
  therefore 
  all 
  their 
  3 
  series 
  of 
  binary 
  axes 
  are 
  of 
  type 
  

   C 
  2 
  , 
  not 
  C* 
  (3 
  of 
  Sohncke). 
  For 
  " 
  62 
  (3 
  of 
  Sohncke) 
  '^should 
  

   be 
  read 
  " 
  64 
  (4 
  of 
  Sohncke)." 
  

  

  ~V~h 
  a 
  PP 
  ears 
  as 
  " 
  V 
  A 
  " 
  on 
  p. 
  51 
  of 
  the 
  Zeitschr./. 
  Kryst. 
  u.. 
  

   Min. 
  xx. 
  — 
  obviously 
  a 
  misprint. 
  The 
  corresponding 
  group 
  

   {58 
  a 
  2 
  ) 
  of 
  Barlow 
  is 
  not 
  given 
  quite 
  correctly 
  by 
  him. 
  He~ 
  

   gives 
  as 
  the 
  position 
  of 
  the 
  centre 
  " 
  On 
  a 
  line 
  midway 
  

   between 
  two 
  neighbouring 
  screw-axes 
  of 
  different 
  sorts 
  in 
  its 
  

   point 
  of 
  intersection 
  with 
  a 
  rotation-axis." 
  This 
  would 
  make 
  

   his 
  types 
  58 
  a\ 
  and 
  58 
  a 
  2 
  identical, 
  and 
  the 
  same 
  as 
  Schoenflies 
  5 
  

  

  Vj'" 
  ; 
  the 
  last 
  phrase 
  should 
  run 
  " 
  midway 
  between 
  its 
  points 
  

   of 
  intersection 
  with 
  a 
  rotation 
  axis." 
  

  

  * 
  Zeitschr. 
  Kryst. 
  Min. 
  xx. 
  (1892) 
  p. 
  56. 
  

   t 
  Ibid, 
  xxiii. 
  (1895) 
  p. 
  56. 
  

  

  