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  LXXXI. 
  Notices 
  respecting 
  New 
  Boohs. 
  

  

  Vectorial 
  Mechanics. 
  By 
  L. 
  Sileeestein", 
  Ph.D., 
  Lecturer 
  in 
  

   Natural 
  Philosophy 
  at 
  the 
  University 
  of 
  Rome. 
  Pp. 
  viii 
  + 
  

   197. 
  London: 
  Macmillan 
  & 
  Co. 
  Price 
  7s. 
  Qd. 
  net. 
  

  

  r 
  PHE 
  use 
  of 
  vector 
  notation, 
  though 
  long 
  delayed, 
  is 
  now 
  grad- 
  

   -*- 
  ually 
  extending. 
  The 
  large 
  amount 
  of 
  work 
  done 
  in 
  connexion 
  

   with 
  the 
  electromagnetic 
  field 
  — 
  a 
  region 
  of 
  investigation 
  which 
  

   brings 
  out 
  very 
  clearly 
  the 
  utility 
  of 
  this 
  notation 
  — 
  has 
  contributed 
  

   mainly 
  to 
  this 
  advance. 
  The 
  particular 
  form 
  which 
  has 
  been 
  most 
  

   adopted 
  is 
  based 
  on 
  that 
  put 
  forward 
  by 
  Oliver 
  Heaviside, 
  and 
  it 
  

   is 
  to 
  Heaviside's 
  excellent 
  book 
  (' 
  Electromagnetic 
  Theory,' 
  1893) 
  

   that 
  one 
  has 
  been 
  accustomed 
  to 
  turn. 
  The 
  great 
  simplification 
  in 
  

   theoretical 
  investigations 
  which 
  the 
  notation 
  introduces 
  is 
  respon- 
  

   sible 
  for 
  its 
  growing 
  employment 
  ; 
  a 
  somewhat 
  lethargic 
  

   unwillingness 
  to 
  trouble 
  about 
  an 
  unfamiliar 
  thing 
  is 
  responsible, 
  

   at 
  any 
  rate 
  in 
  part, 
  for 
  its 
  neglect. 
  There 
  is, 
  however, 
  the 
  

   additional 
  reason 
  that 
  results 
  obtained 
  with 
  remarkable 
  simplicity 
  

   by 
  this 
  method 
  require 
  to 
  be 
  extended 
  into 
  the 
  more 
  familiar 
  

   notation 
  when 
  the 
  question 
  of 
  numerical 
  calculation 
  arises. 
  The 
  

   practical 
  man 
  has 
  therefore 
  been 
  averse 
  from 
  having 
  anything 
  to 
  

   do 
  with 
  it 
  ; 
  but 
  as 
  the 
  practical 
  man 
  is 
  seldom 
  concerned 
  with 
  

   the 
  theoretical 
  proof 
  of 
  principles, 
  his 
  objections 
  can 
  have 
  little 
  

   final 
  weight. 
  

  

  The 
  present 
  volume 
  has 
  for 
  its 
  object 
  the 
  presentation 
  of 
  

   the 
  chief 
  principles 
  and 
  theories 
  of 
  theoretical 
  mechanics 
  in 
  the 
  

   language 
  of 
  vectors. 
  By 
  choosing 
  this 
  branch- 
  of 
  science 
  instead 
  

   of 
  the 
  more 
  recondite 
  science 
  of 
  electromagnetism 
  as 
  a 
  basis 
  for 
  

   exposition, 
  it 
  is 
  reasonably 
  hoped 
  to 
  encourage 
  the 
  diffusion 
  of 
  

   the 
  use 
  of 
  vectorial 
  methods. 
  The 
  main 
  object 
  is 
  kept 
  in 
  view 
  

   throughout. 
  Discussions 
  of 
  the 
  philosophical 
  aspect 
  of 
  mecha- 
  

   nical 
  quantities 
  are 
  consequently 
  excluded. 
  But, 
  starting 
  from 
  

   D'Alembert's 
  principle, 
  the 
  book 
  is 
  a 
  continuous 
  treatise 
  on 
  

   mechanics 
  in 
  vectorial 
  language. 
  This 
  is 
  preceded 
  in 
  Chapter 
  I, 
  

   by 
  an 
  exposition 
  of 
  the 
  notation 
  and 
  of 
  the 
  general 
  properties 
  of 
  

   vectors 
  and 
  the 
  operations 
  to 
  be 
  performed 
  on 
  them. 
  The 
  

   mechanics 
  includes 
  the 
  properties 
  of 
  the 
  motion 
  of 
  rigid 
  bodies, 
  of 
  

   the 
  motions 
  and 
  strains 
  of 
  deformable 
  solids, 
  and 
  hydromechaTiics. 
  

   A 
  series 
  of 
  problems 
  (with 
  hints 
  toward 
  solution) 
  is 
  arranged 
  at 
  the 
  

   end 
  in 
  the 
  order 
  in 
  which 
  the 
  questions 
  referred 
  to 
  occur 
  in 
  the 
  

   text. 
  An 
  appendix 
  contains 
  the 
  Cartesian 
  equivalents 
  of 
  vector 
  

   formulae. 
  

  

  This 
  is 
  no 
  perfunctory 
  exposition 
  of 
  the 
  subject 
  of 
  vectors. 
  

   Dr. 
  Silberstein 
  is 
  an 
  enthusiast 
  for 
  the 
  subject. 
  He 
  decries 
  the 
  

   hopeless 
  complication 
  often 
  introduced 
  into 
  problems 
  by 
  Cartesian 
  

   methods 
  — 
  " 
  a 
  complication 
  which 
  does 
  not 
  arise 
  from 
  the 
  intrinsic 
  

   peculiarities 
  of 
  the 
  phenomena 
  in 
  question, 
  but 
  is 
  wholly 
  artificial, 
  

  

  