﻿652 
  Messrs. 
  E. 
  Bellini 
  and 
  A. 
  Tosi 
  on 
  a 
  

  

  the 
  thermo-galvanometer. 
  The 
  results 
  were 
  always 
  in 
  practical 
  

   agreement 
  with 
  the 
  theory. 
  

  

  The 
  simultaneous 
  excitation 
  o£ 
  the 
  two 
  systems 
  was 
  effected 
  

   by 
  adding, 
  internal 
  to 
  the 
  primary 
  of 
  the 
  transmitting 
  

   radiogoniometer, 
  a 
  winding, 
  fixed 
  in 
  position 
  relatively 
  to 
  

   the 
  primary 
  and 
  inductively 
  excited 
  by 
  it. 
  To 
  this 
  winding- 
  

   is 
  connected 
  the 
  vertical 
  antenna. 
  On 
  turning 
  the 
  movable 
  

   winding 
  o£ 
  the 
  apparatus 
  the 
  excitation 
  of 
  the 
  vertical 
  antenna 
  

   remains 
  constant 
  whilst 
  the 
  excitations 
  of 
  the 
  closed 
  circuits 
  

   forming 
  the 
  aerial 
  of 
  the 
  bilateral 
  system, 
  vary. 
  Consequently, 
  

   to 
  transmit 
  by 
  the 
  unilateral 
  system 
  in 
  a 
  given 
  direction, 
  one 
  

   has 
  merely 
  to 
  turn 
  the 
  movable 
  pointer 
  until 
  it 
  points 
  in 
  this 
  

   direction. 
  

  

  The 
  tests 
  of 
  the 
  unilateral 
  system 
  at 
  long 
  distance 
  were 
  

   made 
  between 
  the 
  stations 
  of 
  Dieppe 
  and 
  Havre, 
  and 
  have 
  

   confirmed 
  the 
  results 
  obtained 
  at 
  short 
  range 
  — 
  that 
  is 
  to 
  say, 
  

   on 
  placing 
  the 
  pointer 
  of 
  the 
  transmitting 
  radiogoniometer 
  

   in 
  the 
  direction 
  of 
  Havre, 
  reception 
  was 
  effected 
  ; 
  on 
  turning 
  

   the 
  pointer 
  to 
  180° 
  from 
  this 
  the 
  reception 
  ceased 
  entirely. 
  

  

  Reception. 
  — 
  The 
  same 
  principle 
  of 
  the 
  superposition 
  of 
  the 
  

   two 
  systems 
  has 
  been 
  applied 
  to 
  the 
  case 
  of 
  the 
  reception. 
  

   Considering 
  the 
  case 
  of 
  a 
  receiving 
  station 
  provided 
  with 
  an 
  

   aerial 
  composed 
  of 
  a 
  single 
  closed 
  oscillatory 
  circuit, 
  fixed 
  in 
  

   position, 
  and 
  of 
  a 
  vertical 
  antenna 
  symmetrically 
  placed 
  with 
  

   respect 
  to 
  the 
  closed 
  oscillatory 
  circuit, 
  let 
  it 
  be 
  supposed 
  

   that 
  any 
  transmitting 
  station 
  is 
  moving 
  along 
  a 
  circumference 
  

   of 
  which 
  the 
  receiving 
  station 
  is 
  the 
  centre 
  ; 
  it 
  is 
  evident 
  that 
  

   the 
  intensity 
  and 
  phase 
  of 
  the 
  oscillatory 
  current 
  in 
  the 
  vertical 
  

   antenna 
  of 
  the 
  receiving 
  station 
  will 
  remain 
  constant, 
  whilst 
  

   in 
  the 
  closed 
  oscillatory 
  circuit 
  they 
  will 
  vary 
  with 
  the 
  position 
  

   of 
  the 
  transmitting 
  station. 
  The 
  intensity 
  passes 
  through 
  two 
  

   maxima 
  and 
  two 
  minima, 
  and 
  its 
  phase 
  varies 
  by 
  180° 
  

   when 
  the 
  transmitting 
  station 
  passes 
  from 
  one 
  side 
  to 
  the 
  

   other 
  of 
  the 
  plane 
  perpendicular 
  to 
  the 
  closed 
  oscillatory 
  

   circuit. 
  Further, 
  although 
  a 
  closed 
  oscillatory 
  circuit 
  utilises 
  

   the 
  variation 
  of 
  magnetic 
  flux 
  across 
  the 
  surface 
  bounded 
  

   by 
  such 
  circuit, 
  the 
  E.M.F. 
  generated 
  in 
  it 
  will 
  be 
  in 
  

   quadrature 
  with 
  the 
  E.M.F. 
  generated 
  in 
  the 
  vertical 
  antenna, 
  

   and 
  the 
  same 
  phase-displacement 
  will 
  exist 
  between 
  the 
  

   currents 
  in 
  the 
  two 
  types 
  of 
  aerials 
  if 
  these 
  -latter 
  are 
  both 
  

   tuned 
  to 
  the 
  length 
  of 
  the 
  waves 
  received. 
  

  

  Let 
  it 
  be 
  supposed, 
  for 
  instance, 
  that 
  the 
  closed 
  oscillatory 
  

   circuit 
  is 
  oriented 
  in 
  a 
  certain 
  meridian 
  and 
  that 
  the 
  trans- 
  

   mitting 
  station 
  in 
  moving 
  about 
  arrives 
  in 
  the 
  plane 
  of 
  the 
  

   closed 
  oscillatory 
  circuit, 
  on 
  the 
  north 
  side. 
  In 
  such 
  a 
  

   position, 
  by 
  bringing 
  the 
  actions 
  of 
  the 
  two 
  systems 
  on 
  the 
  

  

  