﻿280 
  

  

  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1922. 
  

  

  together 
  to 
  tell 
  whether 
  the 
  angle 
  of 
  direction 
  found 
  means 
  to 
  right 
  

   or 
  to 
  left 
  of 
  the 
  vessel. 
  That 
  can 
  be 
  told 
  from 
  the 
  relative 
  loudness 
  

   on 
  the 
  two 
  sides. 
  

  

  The 
  receivers 
  themselves 
  have 
  membranes 
  like 
  a 
  drum 
  or 
  a 
  tele- 
  

   phone, 
  and 
  microphones 
  attached 
  which 
  are 
  connected 
  through 
  the 
  

  

  I 
  Rotary 
  Converter. 
  

  

  .CoNSTAXTSpttoSHtn. 
  

  

  TRANSFORMER* 
  

  

  vwivvv 
  

   Rcgui-atin9 
  Rheostat. 
  

  

  E=j 
  

  

  Synchronizing 
  Fork. 
  

  

  UIOV 
  - 
  IOOW.Lt 
  * 
  

  

  — 
  TT 
  

  

  mwmmm 
  

  

  L 
  C 
  * 
  TEL. 
  

  

  I2SV. 
  D.C 
  

  

  53 
  

  

  t=s 
  

  

  SENOtNO 
  KcY 
  

   on 
  OaCILLATtR 
  

  

  Panel. 
  

  

  Fig. 
  3. 
  — 
  Wiring 
  diagram 
  of 
  depth 
  finder. 
  

  

  electrical 
  compensators 
  for 
  retarding 
  the 
  sounds, 
  so 
  that 
  they 
  join 
  

   to 
  operate 
  the 
  telephones 
  on 
  the 
  observer's 
  head. 
  Their 
  arrangement 
  

   and 
  connections 
  are 
  shown 
  in 
  figures 
  2 
  and 
  3. 
  

  

  Such 
  hydrophones 
  can 
  hear 
  the 
  propellers 
  of 
  their 
  own 
  ship 
  or 
  the 
  

   sounds 
  of 
  a 
  sound-signalling 
  apparatus 
  located 
  at 
  the 
  stern. 
  Pro- 
  

   peller 
  sounds 
  are 
  of 
  low 
  pitch, 
  and 
  so 
  are 
  other 
  water 
  noises 
  like 
  the 
  

  

  