﻿426 
  PROCEEDINGS 
  OF 
  THE 
  CALIFORNIA 
  

  

  A 
  Device 
  for 
  the 
  Solution 
  of 
  the 
  Problem 
  of 
  Lengthening 
  the 
  

   Pendulum 
  of 
  an 
  Astronomical 
  Clock 
  without 
  Stopping 
  or 
  

   Disturbing 
  its 
  Vibrations. 
  

  

  BY 
  T. 
  J. 
  LOWRY. 
  

  

  The 
  mechanism 
  of 
  the 
  astronomical 
  clock, 
  which 
  has 
  so 
  greatly 
  contributed 
  

   to 
  the 
  accuracy 
  as 
  well 
  of 
  astronomical 
  observations 
  as 
  of 
  the 
  determinations 
  

   of 
  longitudes, 
  has 
  been 
  carried 
  to 
  a 
  degree 
  of 
  wonderfully 
  delicate 
  perfection. 
  

   Its 
  correction 
  for 
  varying 
  temperatures 
  has 
  been 
  so 
  complete, 
  and 
  its 
  rate 
  so 
  

   uniform, 
  that 
  the 
  astronomer 
  has 
  hitherto 
  thought 
  best 
  to 
  let 
  it 
  run 
  without 
  

   disturbing 
  it 
  by 
  attempting 
  to 
  adjust 
  the 
  length 
  of 
  the 
  pendulum, 
  even 
  though 
  

   it 
  was 
  uniformly 
  gaining 
  or 
  losing 
  on 
  the 
  time 
  it 
  was 
  desired 
  to 
  keep. 
  Yet 
  the 
  

   very 
  great 
  inconvenience, 
  to 
  the 
  practical 
  astronomer 
  in 
  the 
  observatory, 
  of 
  

   having 
  his 
  clock 
  show 
  a 
  different 
  face 
  time 
  from 
  that 
  given 
  by 
  the 
  ephemeris, 
  

   and 
  the 
  still 
  greater 
  reluctance 
  to 
  stopping 
  his 
  clock 
  when 
  once 
  set 
  going, 
  have 
  

   awakened 
  the 
  ingenuities 
  of 
  astronomers 
  and 
  artists 
  to 
  devise 
  a 
  means 
  of 
  

   lengthening 
  and 
  shortening 
  the 
  pendulum 
  without 
  disturbing 
  its 
  vibrations. 
  

   And 
  success 
  had 
  half 
  crowned 
  their 
  efforts 
  — 
  by 
  fixing 
  a 
  small 
  funnel 
  on 
  the 
  

   face 
  of 
  the 
  pendulum 
  and 
  dropping 
  small 
  shot 
  into 
  it 
  they 
  succeeded 
  well 
  in 
  

   shifting 
  the 
  center 
  of 
  gravity 
  up 
  towards 
  the 
  point 
  of 
  suspension, 
  and 
  thus 
  

   shortened 
  the 
  pendulum 
  without 
  stopping 
  or 
  essentially 
  disturbing 
  its 
  vibra- 
  

   tions. 
  But 
  when 
  they 
  attempted 
  to 
  lengthen 
  the 
  pendulum, 
  by 
  extracting 
  shot 
  

   from 
  the 
  funnel, 
  without 
  disturbing 
  its 
  vibrations, 
  they 
  were 
  baffled 
  in 
  their 
  

   every 
  effort. 
  To 
  drop 
  the 
  shot 
  into 
  the 
  funnel 
  was 
  easy 
  enough, 
  but 
  to 
  get 
  

   them 
  out 
  — 
  that 
  was 
  the 
  question. 
  With 
  a 
  pair 
  of 
  ordinary 
  tweezers 
  and 
  vari- 
  

   ous 
  other 
  mechanical 
  devices 
  they 
  attempted 
  to 
  lift 
  out 
  the 
  shot, 
  but 
  these 
  all 
  

   disturbed 
  the 
  vibrations 
  of 
  the 
  pendulum, 
  and 
  hence 
  were 
  inadequate. 
  Seeing 
  

   this 
  difficulty, 
  it 
  occurred 
  to 
  me 
  that 
  if 
  instead 
  of 
  using 
  the 
  small 
  lead 
  shots 
  

   we 
  used 
  iron 
  shots 
  we 
  could 
  pick 
  them 
  up 
  with 
  a 
  magnet 
  : 
  in 
  fact, 
  they 
  will 
  

   pick 
  themselves 
  up 
  and 
  jump 
  to 
  the 
  magnet 
  if 
  it 
  be 
  held 
  in 
  close 
  proximity 
  to 
  

   them. 
  Of 
  course, 
  the 
  magnet 
  should 
  be 
  of 
  small 
  diameter 
  and 
  not 
  very 
  power- 
  

   ful, 
  so 
  as 
  to 
  avoid 
  picking 
  all 
  the 
  shot 
  out 
  at 
  once, 
  or 
  essentially 
  disturbing 
  the 
  

   vibration 
  of 
  the 
  pendulum 
  by 
  its 
  attraction. 
  Thus, 
  we 
  see, 
  gravity 
  aids 
  us 
  ia 
  

   shortening 
  the 
  vibrating 
  pendulum, 
  and 
  magnetism 
  assists 
  us 
  in 
  lengthening 
  it. 
  

  

  This, 
  I 
  believe, 
  will 
  be 
  found 
  a 
  solution 
  of 
  this 
  problem, 
  as 
  effectual 
  as 
  it 
  is 
  

  

  The 
  Nominating 
  Committee 
  appointed 
  by 
  the 
  Council 
  and 
  Trust- 
  

   ees 
  in 
  joint 
  meeting, 
  reported 
  as 
  follows 
  : 
  

  

  The 
  Nominating 
  Committee 
  appointed 
  by 
  the 
  Council 
  and 
  Trustees 
  of 
  the 
  

   California 
  Academy 
  of 
  Sciences, 
  to 
  prepare 
  a 
  ticket 
  for 
  officers 
  to 
  act 
  during 
  the 
  

   ensuing 
  year, 
  respectfully 
  present 
  to 
  the 
  members 
  of 
  the 
  Academy 
  the 
  

   following 
  names 
  : 
  

  

  