﻿10 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  [Nov. 
  4, 
  

  

  beds 
  of 
  fine-grained 
  sandstone. 
  Purple-coloured 
  veins 
  likewise 
  pass 
  

   through 
  the 
  latter, 
  and 
  fine 
  particles 
  of 
  hornblende 
  and 
  various- 
  

   coloured 
  grains 
  of 
  quartz 
  give 
  a 
  variegated 
  appearance 
  to 
  certain 
  

   cliff-sections. 
  

  

  Along 
  the 
  Nile 
  Valley, 
  north 
  of 
  the 
  First 
  Cataract, 
  where 
  the 
  

   rocks 
  come 
  close 
  to 
  the 
  river, 
  are 
  numerous 
  caves 
  and 
  caverns, 
  both 
  

   in 
  the 
  Sandstone 
  and 
  in 
  the 
  Nummulitic 
  Limestone 
  of 
  Lower 
  Egypt. 
  

   At 
  Gebel 
  Aboofaydee, 
  near 
  Siout 
  (280 
  miles 
  below 
  the 
  First 
  Cata- 
  

   ract), 
  I 
  noticed 
  water-worn 
  caves 
  60 
  to 
  70 
  feet 
  above 
  the 
  highest 
  

   Nile; 
  and 
  below 
  Ibrim, 
  in 
  Nubia, 
  on 
  the 
  right 
  bank, 
  under 
  the 
  

   old 
  stronghold 
  (supposed 
  to 
  be 
  the 
  Primis 
  Parva 
  of 
  the 
  Eomans), 
  

   are 
  numbers 
  of 
  cavities, 
  at 
  various 
  levels 
  above 
  the 
  surface 
  of 
  the 
  

   river, 
  and 
  at 
  heights 
  far 
  exceeding 
  the 
  reach 
  of 
  its 
  greatest 
  inun- 
  

   dations 
  in 
  the 
  present 
  day. 
  The 
  larger 
  caves 
  show 
  the 
  charac- 
  

   teristic 
  alternation 
  of 
  contraction 
  and 
  dilatation 
  of 
  water-worn 
  

   openings 
  ; 
  those 
  within 
  reach 
  of 
  the 
  river 
  contain 
  a 
  fine 
  clay, 
  formed 
  

   from 
  that 
  held 
  in 
  solution 
  by 
  the 
  river, 
  and 
  not 
  the 
  washings 
  of 
  

   currents. 
  This 
  mud 
  is 
  evidently 
  the 
  accumulations 
  of 
  years* 
  ; 
  it 
  is 
  

   much 
  sought 
  after 
  for 
  making 
  the 
  excellent 
  water-jugs 
  of 
  Egypt, 
  

   and 
  is 
  moreover 
  exceedingly 
  well 
  adapted 
  for 
  preserving 
  organic 
  

   remains, 
  which, 
  however, 
  from 
  the 
  nature 
  of 
  the 
  Nubian 
  climate, 
  

   are 
  never 
  likely 
  to 
  be 
  found 
  in 
  the 
  caverns 
  inland. 
  I 
  examined 
  

   several 
  Eox- 
  and 
  Hya3na-dens 
  among 
  the 
  Nubian 
  and 
  Egyptian 
  

   ravines, 
  and, 
  although 
  they 
  contained 
  abundance 
  of 
  bones 
  of 
  animals 
  

   recently 
  killed, 
  there 
  was 
  no 
  dripping 
  from 
  the 
  roofs 
  or 
  any 
  soil 
  to 
  

   cover 
  them 
  up, 
  as 
  would 
  have 
  been 
  the 
  case 
  in 
  countries 
  where 
  rain 
  

   falls 
  in 
  quantity 
  and 
  with 
  regularity. 
  

  

  4. 
  Relation 
  of 
  Temples 
  and 
  Caves 
  to 
  the 
  River-level. 
  — 
  We 
  were 
  

   enabled 
  to 
  record 
  undoubted 
  changes 
  in 
  the 
  direction 
  and 
  bed 
  of 
  the 
  

   river 
  at 
  several 
  points 
  by 
  means 
  of 
  the 
  temples 
  and 
  stela;, 
  and 
  by 
  

   an 
  examination 
  of 
  its 
  present 
  action. 
  Close 
  to 
  the 
  famous 
  rock-temple 
  

   of 
  Abu-Simbul 
  is 
  a 
  smaller 
  temple 
  where 
  the 
  Nile 
  at 
  its 
  height 
  

   washes 
  the 
  door- 
  sill. 
  Again, 
  in 
  the 
  little 
  square-shaped 
  excavation 
  

   on 
  the 
  face 
  of 
  the 
  rock, 
  a 
  stone-throw 
  further 
  northwards, 
  there 
  is 
  

   a 
  seated 
  figure, 
  said 
  to 
  be 
  of 
  the 
  same 
  period 
  as 
  the 
  last, 
  sometime 
  

   between 
  b.c 
  1322 
  and 
  1388, 
  on 
  the 
  legs 
  of 
  which, 
  about 
  midway 
  

   between 
  the 
  knees 
  and 
  ankles, 
  I 
  marked 
  the 
  limit 
  of 
  the 
  high 
  Nile 
  

   of 
  the 
  present 
  day 
  ; 
  moreover 
  the 
  deep 
  soundings 
  along 
  the 
  left 
  bank 
  

   close 
  by 
  these 
  two 
  records, 
  and 
  the 
  shallows 
  and 
  sand-deposits 
  going 
  

   on 
  on 
  opposite 
  banks, 
  show 
  very 
  clearly 
  that 
  the 
  current 
  continues 
  

   to 
  set 
  in 
  on 
  the 
  left 
  bank, 
  which 
  it 
  is 
  wearing 
  away 
  up 
  to 
  the 
  cliffs 
  

   in 
  which 
  the 
  above 
  memorials 
  are 
  constructed. 
  

  

  The 
  old 
  temple 
  at 
  Ombos 
  (22 
  miles 
  north 
  of 
  Assuan), 
  founded 
  in 
  

   the 
  reign 
  of 
  Ptolemy 
  Philometor 
  (about 
  b.c 
  200), 
  is 
  built 
  on 
  a 
  heap 
  

   of 
  alluvium 
  which 
  is 
  now 
  being 
  rapidly 
  undermined, 
  whilst 
  the 
  an- 
  

   cient 
  course 
  of 
  the 
  stream 
  is 
  clearly 
  traceable 
  on 
  the 
  left 
  bank, 
  where 
  

   sand-banks 
  and 
  shallows 
  are 
  now 
  being 
  formed. 
  

  

  At 
  Selsileh 
  the 
  river 
  has 
  evidently 
  changed 
  considerably 
  within 
  

  

  * 
  The 
  sedimentary 
  deposits, 
  when 
  dried, 
  split 
  up 
  into 
  lino 
  horizontal 
  laiuinas 
  

   o! 
  great 
  thinness. 
  See 
  Specimen 
  No. 
  8. 
  

  

  