﻿Hubert 
  Anson 
  Newton, 
  371 
  

  

  thinks 
  it 
  reasonable 
  to 
  attribute 
  a 
  large 
  part 
  of 
  the 
  want 
  of 
  

   parallelism 
  to 
  the 
  action 
  of 
  the 
  atmosphere 
  on 
  bodies 
  of 
  an 
  

   irregular 
  form, 
  such 
  as 
  we 
  have 
  every 
  reason 
  to 
  believe 
  that 
  

   the 
  meteoroids 
  have, 
  when 
  they 
  enter 
  our 
  atmosphere. 
  The 
  

   effect 
  of 
  the 
  heat 
  generated 
  will 
  be 
  to 
  round 
  off 
  the 
  edges 
  and 
  

   prominent 
  parts, 
  and 
  to 
  reduce 
  the 
  meteor 
  to 
  a 
  form 
  more 
  and 
  

   more 
  spherical. 
  It 
  is, 
  therefore, 
  quite 
  natural 
  that 
  the 
  greater 
  

   portion 
  of 
  the 
  curvature 
  of 
  the 
  paths 
  should 
  be 
  in 
  the 
  invisible 
  

   portion 
  and 
  thus 
  escape 
  our 
  notice. 
  It 
  is 
  only 
  in 
  exceptional 
  

   cases 
  that 
  the 
  visible 
  path 
  is. 
  notably 
  curved. 
  

  

  But 
  the 
  great 
  interest 
  of 
  the 
  paper 
  centers 
  in 
  his 
  discussion 
  

   of 
  the 
  relation 
  of 
  this 
  shower 
  to 
  preceding 
  showers, 
  and 
  to 
  the 
  

   orbit 
  of 
  Biela's 
  comet. 
  The 
  changes 
  in 
  the 
  date 
  of 
  the 
  shower 
  

   (from 
  Dec. 
  6 
  to 
  Nov. 
  27) 
  and 
  in 
  the 
  position 
  of 
  the 
  radiant 
  

   are 
  shown 
  to 
  be 
  related 
  to 
  the 
  great 
  perturbations 
  of 
  Biela's 
  

   comet 
  in 
  1791:, 
  1831, 
  and 
  1841-2. 
  The 
  showers 
  observed 
  by 
  

   Brandes, 
  Dec. 
  6th, 
  1798, 
  by 
  Herrick, 
  Dec. 
  7th, 
  1838, 
  and 
  by 
  

   Heis, 
  Dec. 
  8th 
  and 
  10th, 
  1847, 
  are 
  related 
  to 
  the 
  orbit 
  of 
  Biela's 
  

   comet 
  as 
  it 
  was 
  in 
  1772 
  ; 
  while 
  the 
  great 
  showers 
  of 
  1872 
  and 
  

   1885, 
  as 
  well 
  as 
  a 
  trifling 
  display 
  in 
  1867, 
  are 
  related 
  to 
  the 
  

   orbit 
  of 
  1852.* 
  

  

  Assuming, 
  then, 
  that 
  the 
  meteoroids 
  which 
  we 
  met 
  on 
  the 
  

   27th 
  of 
  November, 
  1872, 
  did 
  not 
  leave 
  the 
  immediate 
  neigh- 
  

   borhood 
  of 
  the 
  Biela 
  comet 
  before 
  1841-5, 
  we 
  seem 
  to 
  have 
  

   the 
  data 
  for 
  a 
  very 
  precise 
  determination 
  of 
  their 
  orbit 
  between 
  

   those 
  dates. 
  The 
  same 
  is 
  true 
  of 
  those 
  which 
  we 
  met 
  in 
  1885. 
  

   The 
  computation 
  of 
  these 
  orbits, 
  the 
  author 
  remarks, 
  may 
  

   possibly 
  give 
  evidence 
  for 
  or 
  against 
  the 
  existence 
  of 
  a 
  resisting 
  

   medium 
  in 
  the 
  solar 
  system. 
  

  

  In 
  his 
  last 
  public 
  utterance 
  on 
  the 
  subject 
  of 
  meteors, 
  which 
  

   was 
  on 
  the 
  occasion 
  of 
  the 
  recent 
  sesquicentennial 
  celebration 
  

   of 
  the 
  American 
  Philosophical 
  Society, 
  Professor 
  Newton 
  

   returns 
  to 
  the 
  Biela 
  meteoroids, 
  and 
  finds 
  in 
  the 
  scatter- 
  

   ing 
  which 
  they 
  show 
  in 
  the 
  plane 
  of 
  their 
  orbit 
  the 
  proof 
  of 
  

   a 
  disturbing 
  force 
  in 
  that 
  plane, 
  and 
  therefore 
  not 
  due 
  to 
  the 
  

   planets. 
  The 
  force 
  exerted 
  by 
  the 
  sun 
  appears 
  to 
  be 
  modi- 
  

   fied 
  somewhat 
  as 
  we 
  see 
  it 
  in 
  the 
  comet's 
  tails, 
  where 
  indeed 
  

   the 
  attraction 
  is 
  changed 
  into 
  a 
  repulsion. 
  Something 
  of 
  the 
  

   same 
  sort 
  on 
  a 
  smaller 
  scale 
  relatively 
  to 
  the 
  mass 
  of 
  the 
  bodies 
  

   appears 
  to 
  modify 
  the 
  sun's 
  action 
  on 
  the 
  meteoroids. 
  

  

  In 
  1888 
  Professor 
  Xewton 
  read 
  a 
  paper 
  before 
  the 
  National 
  

   Academy 
  " 
  Upon 
  the 
  relation 
  which 
  the 
  former 
  Orbits 
  of 
  

   those 
  Meteorites 
  that 
  are 
  in 
  our 
  collections, 
  and 
  that 
  were 
  seen 
  

  

  *It 
  is 
  a 
  curious 
  coincidence 
  that 
  the 
  original 
  discoverer 
  of 
  the 
  December 
  

   shower 
  as 
  a 
  periodic 
  phenomenon, 
  Mr. 
  Edward 
  C. 
  Herrick, 
  should 
  have 
  been 
  (with 
  

   a 
  companion, 
  Mr. 
  Francis 
  Bradley,) 
  the 
  first 
  to 
  observe 
  that 
  breaking 
  up 
  of 
  the 
  

   parent 
  body 
  which 
  was 
  destined 
  to 
  reinforce 
  the 
  meteoric 
  stream 
  in 
  so 
  remark- 
  

   able 
  a 
  manner. 
  See 
  this 
  Journal, 
  III, 
  xxxi, 
  pp. 
  85 
  and 
  88. 
  

  

  