﻿428 
  Scientific 
  Intelligence. 
  

  

  set 
  at 
  varying 
  angles 
  and 
  making 
  it 
  possible 
  to 
  compute 
  the 
  

   work 
  expended 
  in 
  their 
  uniform 
  horizontal 
  flight. 
  Thus 
  it 
  is 
  

   proved 
  that 
  less 
  work 
  is 
  required 
  in 
  the 
  aerial 
  motion 
  of 
  heavy 
  

   inclined 
  planes 
  at 
  higher 
  speeds 
  than 
  at 
  lower 
  ones. 
  In 
  the 
  

   quantitative 
  experiments 
  connected 
  with 
  this 
  part 
  of 
  the 
  subject, 
  

   a 
  " 
  component 
  pressure 
  recorder 
  " 
  was 
  used 
  together 
  with 
  a 
  

   " 
  dynamometer-chronograph 
  " 
  to 
  record 
  the 
  speed, 
  the 
  resistance 
  

   to 
  forward 
  motion 
  at 
  the 
  instant 
  of 
  soaring 
  and 
  other 
  attendant 
  

   phenomena. 
  

  

  Reference 
  must 
  be 
  made 
  to 
  the 
  memoir 
  itself 
  for 
  the 
  details 
  of 
  

   the 
  methods 
  and 
  results 
  of 
  the 
  experiments 
  with 
  the 
  instruments, 
  

   alluded 
  to. 
  It 
  is 
  interesting, 
  however, 
  to 
  note 
  the 
  conclusion 
  

   reached, 
  that, 
  " 
  so 
  far 
  as 
  the 
  mere 
  power 
  to 
  sustain 
  heavy 
  bodies 
  

   in 
  the 
  air 
  by 
  mechanical 
  flight 
  goes, 
  such 
  mechanical 
  flight 
  is 
  

   possible 
  icith 
  engines 
  toe 
  now 
  2?ossess, 
  since 
  effective 
  steam 
  engines 
  

   have 
  lately 
  been 
  built 
  weighing 
  less 
  than 
  10 
  pounds 
  to 
  an 
  horse- 
  

   power, 
  and 
  the 
  experiments 
  show 
  that 
  if 
  we 
  multiply 
  the 
  small 
  

   planes 
  which 
  have 
  been 
  actually 
  used, 
  or 
  assume 
  a 
  larger 
  plane 
  

   to 
  have 
  approximately 
  the 
  properties 
  of 
  similar 
  small 
  ones, 
  one 
  

   horse 
  power 
  rightly 
  applied 
  can 
  sustain 
  over 
  200 
  pounds 
  in 
  the 
  

   air 
  at 
  a 
  horizontal 
  velocity 
  of 
  over 
  20 
  meters 
  per 
  second 
  (about 
  

   45 
  miles 
  per 
  hour) 
  and 
  still 
  more 
  at 
  still 
  higher 
  velocities." 
  The 
  

   author 
  adds 
  further 
  that 
  the 
  experiments 
  "afford 
  assurance 
  that 
  

   we 
  can 
  transport 
  (with 
  fuel 
  for 
  a 
  considerable 
  journey 
  and 
  at 
  

   speeds 
  high 
  enough 
  to 
  make 
  us 
  independent 
  of 
  ordinary 
  winds) 
  

   weights 
  many 
  times 
  greater 
  than 
  that 
  of 
  a 
  man." 
  He 
  goes 
  on 
  to 
  

   say 
  (we 
  quote 
  the 
  author's 
  words) 
  that 
  he 
  has 
  "not 
  asserted 
  

   without 
  qualification 
  that 
  mechanical 
  flight 
  is 
  practicably 
  possi- 
  

   ble 
  since 
  this 
  involves 
  questions 
  as 
  to 
  the 
  method 
  of 
  constructing 
  

   the 
  mechanism, 
  of 
  securing 
  its 
  safe 
  ascent 
  and 
  descent 
  and 
  also 
  

   of 
  securing 
  the 
  indispensable 
  condition 
  for 
  the 
  economic 
  use 
  of 
  

   the 
  power 
  I 
  have 
  shown 
  to 
  be 
  at 
  our 
  disposal, 
  the 
  condition, 
  I 
  

   mean, 
  of 
  our 
  ability 
  to 
  guide 
  it 
  the 
  desired 
  horizonal 
  direction 
  

   during 
  transport 
  — 
  questions 
  which 
  in 
  my 
  opinion 
  are 
  only 
  to 
  be 
  

   answered 
  by 
  experiment 
  and 
  which 
  belong 
  to 
  the 
  inchoate 
  art 
  or 
  

   science 
  of 
  aerodromics 
  on 
  which 
  I 
  do 
  not 
  enter. 
  I 
  wish, 
  how- 
  

   ever, 
  to 
  put 
  on 
  record 
  my 
  belief 
  that 
  the 
  time 
  has 
  come 
  for 
  these 
  

   questions 
  to 
  engage 
  the 
  serious 
  attention 
  not 
  only 
  of 
  engineers 
  

   but 
  of 
  all 
  interested 
  in 
  the 
  possibly 
  near 
  practical 
  solution 
  of 
  the 
  

   problem, 
  one 
  of 
  the 
  most 
  important 
  in 
  its 
  consequences 
  of 
  any 
  

   which 
  has 
  ever 
  presented 
  itself 
  in 
  mechanics 
  ; 
  for 
  this 
  solution 
  it 
  is 
  

   here 
  shown 
  cannot 
  longer 
  be 
  considered 
  beyond 
  our 
  capacity 
  to 
  

   reach." 
  

  

  11. 
  The 
  Chemical 
  Analysis 
  of 
  Iron. 
  — 
  A 
  complete 
  account 
  of 
  

   all 
  the 
  best 
  known 
  methods 
  for 
  the 
  analysis 
  of 
  iron, 
  steel, 
  pig- 
  

   iron, 
  iron-ore, 
  limestone, 
  slag, 
  clay, 
  sand, 
  coal, 
  coke 
  and 
  furnace 
  

   and 
  producer 
  gases 
  by 
  Andreav 
  Alexander 
  Blair. 
  Second 
  

   edition. 
  314 
  pp. 
  Philadelphia, 
  1891 
  (J. 
  B. 
  Lippincott 
  Com- 
  

   pany). 
  — 
  The 
  first 
  edition 
  of 
  this 
  valuable 
  and 
  attractive 
  work 
  

   was 
  noticed 
  in 
  volume 
  xxxvi 
  (p. 
  387) 
  of 
  this 
  Journal. 
  In 
  the 
  

  

  