﻿[43] 
  WOEK 
  OF 
  STEAMER 
  ALBATROSS. 
  45 
  

  

  vessel 
  would 
  alternately 
  be 
  in 
  water 
  of 
  76° 
  and 
  of 
  63°, 
  and 
  frequent 
  

   observations, 
  under 
  favorable 
  circumstances, 
  day 
  aiid 
  night, 
  showed 
  

   that 
  when 
  in 
  the 
  warm 
  water 
  a 
  moderate 
  EKE. 
  set 
  was 
  experienced; 
  

   on 
  emerging 
  into 
  cooler 
  water 
  the 
  ship 
  was 
  immediately 
  set 
  to 
  the 
  

   southward, 
  the 
  wind 
  being 
  east 
  to 
  northeast, 
  and 
  on 
  reaching 
  warmer 
  

   water 
  again 
  the 
  same 
  easterly 
  current 
  was 
  found. 
  

  

  The 
  table 
  of 
  hydrographic 
  soundings 
  and 
  record 
  of 
  dredgings 
  and 
  

   trawlings 
  give 
  the 
  position 
  and 
  depth 
  of 
  all 
  soundings 
  taken 
  during 
  the 
  

   year. 
  The 
  numbers 
  above 
  2,000 
  indicate 
  dredging 
  stations. 
  

  

  The 
  ship 
  was 
  swung 
  for 
  deviations 
  in 
  different 
  latitudes 
  three 
  times 
  

   during 
  the 
  year. 
  At 
  Key 
  West, 
  Fla., 
  latitude 
  23° 
  30', 
  in 
  January 
  ; 
  iu 
  

   Narragansett 
  Bay, 
  latitude 
  41° 
  30', 
  in 
  June 
  ; 
  and 
  at 
  the 
  mouth 
  of 
  the 
  

   Potomac 
  River, 
  latitude 
  38°, 
  in 
  October. 
  In 
  each 
  case 
  the 
  ship 
  was 
  

   swung 
  on 
  even 
  keel 
  once 
  with 
  starboard 
  and 
  once 
  with 
  port 
  helm, 
  the 
  

   object 
  observed 
  being 
  the 
  sun. 
  From 
  the 
  mean 
  deviation 
  curves 
  thus 
  

   obtained, 
  the 
  accompanying 
  steering-cards 
  were 
  constructed, 
  in 
  which 
  

   the 
  points 
  of 
  the 
  inner 
  circle 
  represent 
  the 
  magnetic 
  courses 
  to 
  be 
  made, 
  

   the 
  radial 
  lines 
  from 
  them 
  showing 
  on 
  the 
  outer 
  circle 
  the 
  correspond- 
  

   ing 
  courses 
  to 
  be 
  steered 
  by 
  the 
  standard 
  compass. 
  

  

  The 
  deviations 
  are 
  nearly 
  the 
  same 
  now 
  as 
  in 
  the 
  spring 
  of 
  1883 
  for 
  

   the 
  same 
  latitude. 
  At 
  the 
  time 
  of 
  swinging 
  ship 
  in 
  the 
  Chesapeake 
  

   then, 
  there 
  were 
  three 
  spare 
  pieces 
  of 
  iron 
  railing 
  lashed 
  fore 
  and 
  aft 
  

   to 
  the 
  hand-rail 
  on 
  the 
  port 
  side 
  abreast 
  of 
  the 
  compass, 
  and 
  8 
  feet 
  from 
  

   it; 
  these 
  were 
  removed 
  shortly 
  afterwards, 
  and 
  the 
  change 
  in 
  the 
  mag- 
  

   netic 
  conditions 
  affected 
  the 
  compass 
  somewhat, 
  the 
  greatest 
  westerly 
  

   deviations 
  (on 
  the 
  ESE. 
  course) 
  becoming 
  \ 
  point 
  greater 
  than 
  the 
  

   greatest 
  easterly 
  deviation 
  on 
  the 
  west 
  course, 
  while 
  previously 
  they 
  had 
  

   been 
  practically 
  equal. 
  All 
  subsequent 
  swingings 
  were 
  performed 
  un- 
  

   der 
  the 
  same 
  circumstances, 
  mutually, 
  as 
  regards 
  movable 
  metal 
  masses. 
  

  

  There 
  has 
  been 
  observed 
  a 
  noticeable 
  illustration 
  of 
  the 
  well-known 
  

   reciprocally 
  inductive 
  influences 
  of 
  magnetic 
  needles 
  and 
  masses 
  of 
  

   iron 
  in 
  certain 
  positions 
  relative 
  to 
  each 
  other 
  and 
  to 
  the 
  magnetic 
  me- 
  

   ridian. 
  Immediately 
  abreast 
  of 
  the 
  center 
  of 
  the 
  standard 
  compass, 
  12 
  

   feet 
  7 
  inches 
  from 
  it 
  on 
  the 
  starboard 
  side, 
  is 
  the 
  forward 
  vertical 
  iron 
  

   davit 
  of 
  the 
  seine 
  boat. 
  When 
  swung 
  in, 
  the 
  head 
  of 
  this 
  curved 
  davit 
  

   is 
  7 
  feet 
  9 
  inches 
  laterally 
  and 
  4 
  feet 
  vertically 
  from 
  the 
  center 
  of 
  the 
  

   card 
  ; 
  when 
  rigged 
  out 
  it 
  is 
  17 
  feet 
  5 
  inches 
  off 
  later-ally 
  and 
  4 
  feet 
  

   vertically, 
  the 
  body 
  of 
  the 
  davit 
  remaining 
  stationary. 
  It 
  has 
  been 
  

   noticed 
  for 
  a 
  long 
  time 
  that 
  the 
  compass 
  is 
  markedly 
  affected 
  by 
  the 
  

   latter 
  position 
  of 
  the 
  davit, 
  but 
  it 
  is 
  usually 
  kept 
  rigged 
  in 
  when 
  at 
  sea, 
  

   in 
  the 
  same 
  position 
  as 
  when 
  the 
  ship 
  is 
  being 
  swung 
  on 
  even 
  beam. 
  

   There 
  has 
  been 
  neither 
  occasion 
  nor 
  opportunity 
  to 
  prepare 
  a 
  separate 
  

   curve 
  of 
  deviations 
  with 
  it 
  rigged 
  out. 
  Isolated 
  observations 
  show 
  that 
  

   the 
  greatest 
  disturbance 
  occurs 
  on 
  the 
  northerly 
  and 
  southerly 
  courses. 
  

   In 
  latitude 
  35° 
  to 
  40°, 
  swinging 
  the 
  davits 
  out 
  changes 
  the 
  deviation 
  

   about 
  one 
  point 
  to 
  the 
  westward 
  on 
  a 
  £T. 
  by 
  E. 
  course, 
  and 
  about 
  the 
  

  

  