70 
ME.  HOENEE  ON  THE  AELUVIAE  EAXD  OF  EGYPT. 
and  these  are  also  caused  by  irregularities  in  the  surface  of  the  ground.  These  eddies 
■ are  often  very  wide,  and  according  to  their  strength  and  velocity  scoop  out  the  ground, 
leaving  sediment  around  the  areas  thus  scooped  out.  Villages,  dykes,  plantations,  and 
even  solitary  trees,  together  with  the  sinuosities  of  the  valley,  alter  the  direction,  the 
extent,  and  the  velocities  of  these  inundation  eddies,  and  consequently  the  quantities 
and  areas  of  the  deposits  of  sediment.  Sometimes  also  the  muddy  water  of  the  Vile  is 
added  to  by  torrents  from  the  hills,  which  come  down  charged  with  clay  and  sand  from 
the  deserts.  Hence  some  patches  of  land  are  of  a dark  brown  argillaceous  nature,  others 
more  or  less  yellow,  and  more  or  less  sandy,  in  proportion  to  the  matter  suspended  in 
the  torrents,  and  according  as  their  flow  has  been  retarded.  After  the  retiring  of  the 
flood,  a series  of  lakes  are  found  at  different  levels,  produced  by  the  eddies,  and  they  are 
often  flUed  up  by  the  sand  bloAving  over  them  being  retained  by  the  water.  The 
removal  of  a plantation,  the  forming  of  a new  one  in  another  dii’ection,  a new  dyke,  a 
new  hamlet,  will  all  cause  disturbances  in  the  direction  of  the  eddies,  and  consequent 
alterations  in  the  nature  and  amount  of  the  sediment  deposited,  causing  also  patches  of 
land  adjoining  each  other  to  fluctuate  greatly  in  value  to  the  cultivator. 
The  lands  nearest  the  river  which  are  irrigated  by  water,  let  in  upon  them  dfr-ect  from 
it,  receive  a greater  amount  of  sediment,  for  the  river  water  during  the  inundation  has 
more  suspended  in  it  than  that  in  the  canals,  especially  those  at  a distance,  and  the  river 
water  must  necessarily  soon  deposit  the  coarser  and  heavier  matter.  Thus  the  strips  of 
land  along  the  dykes  that  skirt  the  river,  and  the  dykes  of  the  great  canals  being  ii'iigated 
by  water  holding  the  maximum  of  suspended  matter,  are  generally  higher  than  the  rest 
of  the  valley ; and,  from  the  same  cause,  the  strip  of  land  between  the  river’s  ordinary 
channel  and  its  embankment  is  higher  than  that  on  the  other  side  of  the  embankment. 
From  the  above  description  of  the  various  circumstances  which  affect  the  distribution 
of  the  Nile  sediment  over  the  land,  it  is  obvious  that  the  depth  of  the  annual  deposit  by 
the  inundation  must  be  very  different  in  different  parts  of  the  valley,  and  consequently 
the  same  lapse  of  time  may  he  represented  hy  different  depths  of  the  soil. 
The  underground  filtration  Water. 
On  examining  the  sections  of  the  pits,  it  will  be  seen  that  filtration  water  was  reached 
at  very  different  levels,  at  the  same  period  of  the  year,  even  in  the  case  of  those  sepa- 
rated only  by  a short  distance.  Thus,  in  Plate  II. — 
feet. 
In  Pit  K*,  on  4 th  August  1852,  it  was  reached  at 19 
In  Pit  No.  2,  45  yards  south,  on  the  same  day 16 
In  Pit  No.  3,  52  yards  north,  on  the  same  day 17 
In  Pit  No.  4,  260  yards  north,  on  29th  June 30 
In  Plate  III.— 
In  Pit  No.  I,  on  22nd  August  1852,  at I0‘9 
In  Pit  No.  2,  66  yards  east  of  No.  1,  on  the  same  day  ....  I5'9 
