﻿374 
  MISS 
  E. 
  ASTON 
  : 
  ANALYSES 
  OF 
  WATER 
  [Aug. 
  1897,, 
  

  

  III. 
  Water 
  Analyses. 
  

   By 
  Miss 
  E. 
  Aston, 
  B.Sc. 
  

  

  The 
  water 
  was 
  collected 
  from 
  wells 
  in 
  the 
  Nubian 
  Desert 
  in* 
  

   December 
  1894 
  by 
  Capt. 
  H. 
  G. 
  Lyons, 
  B.E., 
  who 
  has 
  sent 
  with 
  each 
  

   specimen 
  the 
  following 
  description 
  : 
  — 
  

  

  1. 
  Murrat 
  Wells. 
  

  

  Water-surface 
  10 
  feet 
  from 
  the 
  ground 
  ; 
  depth 
  2 
  feet 
  6 
  inches. 
  If 
  

   the 
  water 
  is 
  all 
  used 
  up 
  by 
  a 
  caravan, 
  the 
  well 
  refills 
  in 
  a 
  few 
  hours,, 
  

   trickling 
  in 
  at 
  the 
  sides. 
  Last 
  fall 
  of 
  rain 
  in 
  November 
  1891, 
  except 
  

   for 
  two 
  or 
  three 
  showers. 
  No 
  vegetation 
  within 
  half 
  a 
  mile 
  of 
  the 
  

   wells, 
  which 
  are 
  sunk 
  in 
  the 
  sand-and-gravel 
  detritus 
  filling 
  the 
  

   valley. 
  The 
  supply 
  of 
  water 
  is 
  said 
  by 
  the 
  Arabs 
  to 
  be 
  unlimited.. 
  

   Wells 
  from 
  1 
  to 
  8 
  in 
  number, 
  open 
  at 
  various 
  times. 
  

  

  2. 
  Bir 
  Tilat 
  Abda. 
  

  

  Called 
  by 
  the 
  Arabs 
  a 
  ' 
  bitter 
  ' 
  well. 
  Water 
  20 
  feet 
  from 
  the 
  

   surface 
  ; 
  well 
  sunk 
  in 
  sand-and-gravel 
  detritus. 
  Considerable 
  vege- 
  

   tation 
  around 
  it. 
  Last 
  rain 
  in 
  November 
  1891. 
  

  

  3. 
  Bir 
  Ab 
  Araga. 
  

  

  Water 
  20 
  feet 
  from 
  the 
  surface. 
  A 
  moderate 
  number 
  of 
  trees 
  and 
  

   shrubs 
  in 
  the 
  vicinity. 
  Last 
  rain 
  fell 
  in 
  November 
  1891. 
  J 
  ^Used 
  by 
  

   the 
  Arabs 
  who 
  live 
  in 
  the 
  neighbourhood. 
  

  

  The 
  tables 
  (p. 
  375) 
  give 
  the 
  analyses 
  of 
  the 
  waters. 
  In 
  the 
  

   first 
  table 
  the 
  figures 
  are 
  the 
  actual 
  amounts 
  of 
  the 
  substances 
  

   found 
  ; 
  the 
  second 
  table 
  gives 
  the 
  approximate 
  constitution. 
  The 
  

   wells 
  are 
  numbered 
  as 
  above 
  : 
  — 
  1 
  = 
  Murrat, 
  2 
  = 
  Bir 
  Tilat 
  Abda, 
  

   3 
  = 
  Bir 
  Ab 
  Araga. 
  

  

  Quantities 
  are 
  tabulated 
  in 
  grains 
  per 
  gallon. 
  The 
  'total 
  solid 
  

   matter 
  ' 
  was 
  found 
  by 
  direct 
  evaporation. 
  The 
  ammonia 
  is 
  expressed, 
  

   in 
  the 
  usual 
  manner, 
  in 
  parts 
  per 
  million. 
  

  

  PLATE 
  XXVI. 
  

  

  Geological 
  sketch-map 
  of 
  a 
  portion 
  of 
  the 
  Nubian 
  Desert 
  south-east 
  

   of 
  Korosko, 
  on 
  the 
  scale 
  of 
  16 
  miles 
  to 
  1 
  inch. 
  

  

  Discussion. 
  

  

  Prof. 
  Hull 
  was 
  glad 
  to 
  find 
  that 
  Capt. 
  Lyons 
  was 
  continuing 
  

   his 
  geological 
  observations 
  up 
  the 
  Valley 
  of 
  the 
  Nile. 
  He 
  presumed 
  

   that 
  those 
  described 
  were 
  the 
  result 
  of 
  a 
  reconnaissance 
  made 
  in 
  

   advance 
  of 
  the 
  Geological 
  Survey 
  of 
  Egypt, 
  and 
  they 
  seemed 
  to 
  show 
  

   that 
  the 
  relations 
  of 
  the 
  various 
  formations 
  above 
  the 
  First 
  Cataract 
  

   were 
  similar 
  to 
  those 
  about 
  Assuan. 
  The 
  old 
  Archaean 
  meta- 
  

   morphic 
  rocks 
  were 
  found 
  peering 
  up 
  through 
  the 
  nearly 
  horizontal 
  

  

  