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  Hubert 
  Anson 
  Newton. 
  

  

  We 
  mention 
  this 
  paper 
  first, 
  because 
  it 
  seems 
  to 
  represent 
  

   the 
  culmination 
  of 
  a 
  line 
  of 
  activity 
  into 
  which 
  Professor 
  New- 
  

   ton 
  had 
  entered 
  much 
  earlier. 
  We 
  must 
  go 
  back 
  to 
  consider 
  

   other 
  papers 
  which 
  he 
  had 
  published 
  in 
  the 
  mean 
  time. 
  

  

  His 
  first 
  papers 
  on 
  this 
  subject, 
  1860-62,* 
  were 
  principally 
  

   devoted 
  to 
  the 
  determination 
  of 
  the 
  paths 
  and 
  velocities 
  of 
  

   certain 
  brilliant 
  meteors 
  or 
  fireballs, 
  which 
  had 
  attracted 
  the 
  

   attention 
  of 
  observers 
  in 
  different 
  localities. 
  Three 
  of 
  these 
  

   appeared 
  to 
  have 
  velocities 
  much 
  greater 
  than 
  is 
  possible 
  for 
  

   permanent 
  members 
  of 
  the 
  solar 
  system. 
  To 
  another 
  a 
  partic- 
  

   ular 
  interest 
  attached 
  as 
  belonging 
  to 
  the 
  August 
  shower, 
  

   although 
  exceptional 
  in 
  size. 
  For 
  this 
  he 
  calculated 
  the 
  

   elements 
  of 
  the 
  orbit 
  which 
  would 
  give 
  the 
  observed 
  path 
  and 
  

   velocity. 
  But 
  the 
  determination 
  of 
  the 
  velocity 
  in 
  such 
  cases, 
  

   which 
  depends 
  upon 
  the 
  estimation 
  by 
  the 
  observers 
  of 
  the 
  

   time 
  of 
  flight, 
  is 
  necessarily 
  very 
  uncertain, 
  and 
  at 
  best 
  affords 
  

   only 
  a 
  lower 
  limit 
  for 
  the 
  value 
  of 
  the 
  original 
  velocity 
  of 
  the 
  

   body 
  before 
  it 
  encountered 
  the 
  resistance 
  of 
  the 
  earth's 
  atmo- 
  

   sphere. 
  This 
  would 
  seem 
  to 
  constitute 
  an 
  insuperable 
  difficulty 
  

   in 
  the 
  determination 
  of 
  the 
  orbits 
  of 
  meteoroids, 
  to 
  use 
  the 
  

   term 
  which 
  Professor 
  Newton 
  applied 
  to 
  these 
  bodies, 
  before 
  

   they 
  enter 
  the 
  earth's 
  atmosphere 
  to 
  appear 
  for 
  a 
  moment 
  as 
  

   luminous 
  meteors. 
  Yet 
  it 
  has 
  been 
  completely 
  overcome 
  in 
  

   the 
  case 
  of 
  the 
  November 
  meteors 
  or 
  Leonids, 
  as 
  they 
  are 
  

   called 
  from 
  the 
  constellation 
  from 
  which 
  they 
  appear 
  to 
  radi- 
  

   ate. 
  This 
  achievement 
  constitutes 
  one 
  of 
  the 
  most 
  interesting 
  

   chapters 
  in 
  the 
  history 
  of 
  meteoric 
  science, 
  and 
  gives 
  the 
  sub- 
  

   ject 
  an 
  honorable 
  place 
  among 
  the 
  exact 
  sciences. 
  

  

  In 
  the 
  first 
  place, 
  by 
  a 
  careful 
  study 
  of 
  the 
  records, 
  Professor 
  

   Newton 
  showed 
  that 
  the 
  connection 
  of 
  early 
  showers 
  with 
  

   those 
  of 
  1799 
  and 
  1833 
  had 
  been 
  masked 
  by 
  a 
  progressive 
  

   change 
  in 
  the 
  time 
  of 
  the 
  year 
  in 
  which 
  the 
  shower 
  occurs. 
  

   This 
  change 
  had 
  amounted 
  to 
  a 
  full 
  month 
  between 
  A. 
  D. 
  902, 
  

   when 
  the 
  shower 
  occurred 
  on 
  October 
  13, 
  and 
  1833, 
  when 
  it 
  

   occurred 
  on 
  November 
  13. 
  It 
  is 
  in 
  part 
  due 
  to 
  the 
  precession 
  

   of 
  the 
  equinoxes, 
  and 
  in 
  part 
  to 
  the 
  motion 
  of 
  the 
  node 
  where 
  

   the 
  earth's 
  orbit 
  meets 
  that 
  of 
  the 
  meteoroids. 
  This 
  motion 
  

   must 
  be 
  attributed 
  to 
  the 
  perturbations 
  of 
  the 
  orbits 
  of 
  the 
  

   meteoroids 
  which 
  are 
  produced 
  by 
  the 
  attractions 
  of 
  the 
  planets, 
  

   and 
  being 
  in 
  the 
  direction 
  opposite 
  to 
  that 
  of 
  the 
  equinoxes, 
  

   Professor 
  Newton 
  inferred 
  that 
  the 
  motion 
  of 
  the 
  meteoroids 
  

   must 
  be 
  retrograde. 
  

  

  The 
  showers 
  do 
  not, 
  however, 
  occur 
  whenever 
  the 
  earth 
  

   passes 
  the 
  node, 
  but 
  only 
  when 
  the 
  passage 
  occurs 
  within 
  a 
  year 
  

   or 
  two 
  before 
  or 
  after 
  the 
  termination 
  of 
  a 
  cycle 
  of 
  33.25 
  years. 
  

   This 
  number 
  is 
  obtained 
  by 
  dividing 
  the 
  interval 
  between 
  the 
  

  

  *This 
  Journal, 
  II, 
  xxx, 
  p. 
  186; 
  xxxii, 
  p. 
  448 
  ; 
  and 
  xxxiii, 
  p. 
  338. 
  

  

  