﻿180 
  

  

  With 
  regard 
  to 
  these 
  tables, 
  it 
  must 
  be 
  remembered 
  that 
  

   the 
  success 
  or 
  want 
  of 
  it 
  is 
  only 
  by 
  comparison 
  with 
  previous 
  

   years, 
  nor 
  does 
  it 
  necessarily 
  mean 
  that 
  there 
  has 
  been 
  even 
  a 
  

   moderate 
  attachment, 
  but 
  only 
  that 
  one 
  year 
  was 
  better 
  than 
  

   another. 
  

  

  By 
  combining 
  the 
  1st 
  and 
  2d 
  classes 
  and 
  3d 
  and 
  4th 
  on 
  each 
  

   bed, 
  and 
  combining 
  such 
  beds 
  as 
  are 
  similarly 
  situated 
  and 
  

   contiguous, 
  I 
  have 
  arranged 
  the 
  following 
  table 
  for 
  compari- 
  

   son 
  with 
  the 
  similar 
  one 
  of 
  the 
  dredging 
  results 
  on 
  the 
  beds 
  

   in 
  the 
  Bay: 
  

  

  