﻿Intelligence 
  and 
  Miscellaneous 
  Articles. 
  543 
  

  

  this, 
  for 
  frequent 
  casas 
  of 
  glacial 
  deposits 
  filling 
  the 
  bottoms 
  of 
  

   these 
  submerged 
  valleys 
  are 
  recorded. 
  

  

  The 
  fact 
  that 
  in 
  the 
  Solent 
  and 
  Thames 
  the 
  Glacial 
  deposits 
  

   border 
  the 
  sides 
  of 
  the 
  valleys, 
  and 
  do 
  not 
  occur 
  at 
  the 
  bottom 
  as 
  

   in 
  the 
  case 
  of 
  the 
  valleys 
  described 
  in 
  the 
  paper, 
  indicates 
  that 
  the 
  

   latter 
  are 
  older 
  than 
  the 
  former, 
  though 
  they 
  present 
  features 
  

   similar 
  to 
  those 
  of 
  some 
  of 
  the 
  valleys 
  of 
  the 
  North-east 
  and 
  North- 
  

   west 
  of 
  England. 
  

  

  2. 
  ' 
  Some 
  New 
  Carboniferous 
  Plants, 
  and 
  how 
  they 
  contributed 
  

   to 
  the 
  Formation 
  of 
  Coal-Seams.' 
  liy 
  W. 
  S. 
  Gresley, 
  Esq., 
  F.Gr.S. 
  

  

  The 
  author, 
  in 
  a 
  paper 
  published 
  in 
  abstract 
  in 
  the 
  Society's 
  

   Quarterly 
  Journal 
  for 
  May 
  1897 
  (vol. 
  liii. 
  p. 
  245), 
  argued 
  that 
  certain 
  

   brilliant 
  black 
  laminae 
  in 
  coal, 
  and 
  similar 
  materials 
  found 
  among 
  

   some 
  mechanical 
  sediments 
  of 
  the 
  Coal 
  Measures, 
  pointed 
  to 
  the 
  

   former 
  existence 
  of 
  an 
  aquatic 
  plant. 
  In 
  the 
  present 
  communication 
  

   he 
  describes 
  structures 
  in 
  the 
  pitch-coal 
  laminae 
  of 
  bituminous 
  coal 
  

   and 
  in 
  the 
  gloss}' 
  black 
  layers 
  of 
  anthracite 
  which 
  he 
  believes 
  to 
  

   be 
  indications 
  of 
  two 
  other 
  kinds 
  of 
  plants, 
  and 
  states 
  that 
  he 
  

   has 
  examined 
  structures 
  which 
  may 
  be 
  due 
  to 
  some 
  other 
  kinds 
  of 
  

   vegetation. 
  

  

  LX. 
  Intelligence 
  and 
  Miscellaneous 
  Articles. 
  

  

  LIQUID 
  HYDROGEN. 
  

   A 
  T 
  the 
  Meeting 
  of 
  the 
  Royal 
  Society 
  yesterday 
  afternoon 
  

   ■*-*- 
  Professor 
  Dewar 
  contributed 
  a 
  preliminary 
  note 
  on 
  the 
  

   liquefaction 
  of 
  hydrogen 
  and 
  helium. 
  

  

  Professor 
  Dewar 
  said 
  that 
  in 
  1895 
  he 
  described 
  apparatus 
  for 
  

   the 
  production 
  of 
  a 
  jet 
  of 
  hydrogen 
  containing 
  liquid, 
  and 
  showed 
  

   how 
  such 
  a 
  jet 
  could 
  be 
  used 
  to 
  cool 
  bodies 
  below 
  the 
  temperature 
  

   that 
  could 
  be 
  reached 
  with 
  liquid 
  air, 
  though 
  all 
  attempts 
  to 
  collect 
  

   the 
  liquid 
  hydrogen 
  failed. 
  So 
  far 
  no 
  investigator 
  had 
  improved 
  on 
  

   the 
  results 
  described 
  in 
  1895 
  ; 
  and 
  as 
  the 
  type 
  of 
  apparatus 
  em- 
  

   ployed 
  in 
  those 
  experiments 
  worked 
  well, 
  it 
  was 
  resolved 
  to 
  con- 
  

   struct 
  a 
  much 
  larger 
  liquid-air 
  plant, 
  and 
  to 
  combine 
  with 
  it 
  

   circuits 
  and 
  arrangements 
  for 
  the 
  liquefaction 
  of 
  hydrogen. 
  The 
  

   apparatus 
  took 
  a 
  year 
  to 
  build 
  up, 
  and 
  many 
  months 
  were 
  occupied 
  

   in 
  testing 
  and 
  in 
  making 
  preliminary 
  trials. 
  The 
  many 
  failures 
  

   and 
  defeats 
  need 
  not 
  be 
  detailed. 
  On 
  May 
  10 
  an 
  experiment 
  was 
  

   started 
  with 
  hydrogen 
  cooled 
  to 
  —205° 
  C., 
  and 
  escaping 
  conti- 
  

   nuously 
  under 
  a 
  pressure 
  of 
  180 
  atmospheres 
  from 
  the 
  nozzle 
  of 
  

   a 
  coil 
  of 
  pipe 
  at 
  the 
  rate 
  of 
  10 
  to 
  15 
  cubic 
  feet 
  a 
  minute, 
  in 
  a 
  

   vacuum 
  vessel 
  doubly 
  silvered, 
  aud 
  of 
  special 
  construction, 
  sur- 
  

   rounded 
  with 
  a 
  space 
  kept 
  below 
  —200° 
  C. 
  AVith 
  these 
  arrange- 
  

   ments 
  liquid 
  hydrogen 
  began 
  to 
  drop 
  from 
  this 
  vacuum 
  vessel 
  into 
  

   another, 
  doubly 
  isolated 
  by 
  being 
  enclosed 
  within 
  a 
  third, 
  and 
  in 
  

   five 
  minutes 
  20 
  cub. 
  centim. 
  of 
  liquid 
  were 
  collected. 
  The 
  hydrogen 
  

   jet 
  then 
  froze 
  up 
  from 
  the 
  solidification 
  of 
  air 
  in 
  the 
  pipes 
  of 
  the 
  

   apparatus. 
  The 
  yield 
  of 
  liquid 
  was 
  about 
  1 
  per 
  cent, 
  of 
  the 
  gas. 
  

   In 
  the 
  liquid 
  condition 
  the 
  hydrogen 
  was 
  clear 
  and 
  colourless, 
  

  

  