﻿110 
  Agassiz- 
  — 
  Explorations 
  of 
  the 
  "Albatross." 
  

  

  at 
  least 
  40 
  to 
  50 
  feet 
  lower 
  than 
  the 
  rim 
  of 
  either 
  face 
  of 
  the 
  

   island. 
  The 
  sink 
  occupies 
  a 
  little 
  more 
  than 
  one-third 
  the 
  

   length 
  of 
  the 
  island. 
  It 
  is 
  deeper 
  at 
  its 
  southern 
  extremity, 
  

   where 
  it 
  is 
  said 
  to 
  be 
  75 
  to 
  100 
  feet 
  below 
  the 
  rim 
  of 
  the 
  

   adjoining 
  cliffs. 
  

  

  It 
  is 
  difficult 
  to 
  determine 
  if 
  this 
  sink 
  is 
  the 
  remnant 
  of 
  the 
  

   former 
  lagoon 
  of 
  the 
  island, 
  or 
  of 
  a 
  sound 
  formed 
  during 
  its 
  

   elevation 
  ; 
  or 
  if 
  it 
  has 
  been 
  formed 
  by 
  the 
  action 
  of 
  rain 
  and 
  

   atmospheric 
  agencies. 
  The 
  amount 
  of 
  denudation 
  and 
  erosion 
  

   to 
  which 
  this 
  island 
  has 
  been 
  subjected 
  is 
  very 
  great, 
  as 
  is 
  

   clearly 
  indicated 
  by 
  the 
  small 
  canons, 
  pinnacles, 
  and 
  walls 
  of 
  

   limestone, 
  as 
  well 
  as 
  by 
  the 
  crevasses 
  which 
  occur 
  in 
  the 
  sur- 
  

   face 
  of 
  the 
  basin 
  in 
  all 
  directions. 
  The 
  extent 
  to 
  which 
  this 
  

   action 
  has 
  penetrated 
  into 
  the 
  mass 
  of 
  the 
  island 
  is 
  also 
  plainly 
  

   shown 
  by 
  the 
  great 
  number 
  of 
  caverns 
  which 
  crop 
  out 
  at 
  all 
  

   levels 
  along 
  the 
  sea 
  face 
  of 
  the 
  cliffs, 
  some 
  of 
  which 
  are 
  of 
  

   great 
  height, 
  and 
  extend 
  as 
  long 
  galleries 
  into 
  the 
  interior 
  of 
  

   the 
  island. 
  It 
  is, 
  of 
  course, 
  difficult, 
  in 
  the 
  face 
  of 
  this 
  exten- 
  

   sive 
  denudation 
  and 
  erosion, 
  to 
  state 
  positively 
  what 
  may 
  be 
  

   part 
  of 
  the 
  ancient 
  lagoon, 
  or 
  sound, 
  and 
  what 
  has 
  been 
  carried 
  

   away 
  by 
  atmospheric 
  and 
  other 
  agencies 
  since 
  the 
  elevation 
  of 
  

   the 
  island. 
  At 
  the 
  south 
  end 
  of 
  the 
  island, 
  which 
  is 
  lower 
  

   than 
  the 
  northern 
  part, 
  there 
  are 
  only 
  two 
  distinct 
  terraces, 
  

   while 
  at 
  the 
  northern 
  end 
  four 
  terraces 
  can 
  be 
  traced. 
  The 
  

   southern 
  extremity, 
  however, 
  is 
  still 
  higher 
  than 
  the 
  deepest 
  

   part 
  of 
  the 
  central 
  sink 
  of 
  the 
  island. 
  

  

  From 
  Makatea, 
  we 
  visited 
  Niau, 
  Apataki, 
  Tikei, 
  Fakarava, 
  

   Anaa, 
  Tahanea, 
  Raroia, 
  Takume, 
  Makemo, 
  Tekokota, 
  Hikueru, 
  

   Marokau, 
  Hao, 
  Aki-Aki, 
  Nukutavake, 
  going 
  as 
  far 
  east 
  as 
  

   Pinaki, 
  when 
  we 
  turned 
  westward 
  again, 
  to 
  Nukutipipi. 
  

  

  On 
  arriving 
  at 
  Pinaki 
  we 
  decided 
  to 
  give 
  up 
  the 
  exploration 
  

   of 
  the 
  eastern 
  extremity 
  of 
  the 
  Paumotus, 
  and 
  not 
  to 
  make 
  

   our 
  contemplated 
  visit 
  to 
  the 
  Gambier 
  Islands, 
  our 
  time 
  hav- 
  

   ing 
  been 
  greatly 
  curtailed 
  by 
  delays 
  at 
  Fakarava 
  and 
  Makemo, 
  

   from 
  bad 
  weather 
  and 
  the 
  non-arrival 
  of 
  our 
  coal 
  supply. 
  We 
  

   therefore 
  reluctantly 
  turned 
  westward 
  again 
  and 
  made 
  for 
  the 
  

   Gloucester 
  Islands. 
  These, 
  as 
  well 
  as 
  Hereheretue, 
  proved 
  

   most 
  interesting 
  ; 
  they 
  formed, 
  as 
  it 
  were, 
  an 
  epitome 
  of 
  what 
  

   we 
  had 
  seen 
  on 
  a 
  gigantic 
  scale 
  in 
  the 
  larger 
  atolls 
  of 
  the 
  

   western 
  and 
  central 
  Paumotus. 
  We 
  could 
  see 
  at 
  a 
  glance 
  in 
  

   such 
  small 
  atolls 
  as 
  Nukutipipi 
  and 
  Anu-Anurunga 
  the 
  con- 
  

   nection 
  between 
  structural 
  features 
  which, 
  in 
  an 
  atoll 
  of 
  40 
  

   miles 
  in 
  length 
  and 
  from 
  10 
  to 
  15 
  miles 
  in 
  width, 
  it 
  was 
  often 
  

   difficult 
  to 
  determine, 
  

  

  We 
  anchored 
  in 
  Fakarava 
  and 
  Makemo 
  Lagoons, 
  spending 
  a 
  

   number 
  of 
  days 
  in 
  both 
  these 
  atolls. 
  We 
  usually 
  timed 
  our 
  

   visits 
  to 
  the 
  islands 
  where 
  we 
  could 
  not 
  anchor 
  so 
  as 
  to 
  spend 
  

  

  