408 
On  River  Conservancy, 
would  be  less  likely  to  grow  or  shoals  to  accumulate,  and 
provision  would  be  secured  for  flood-water  without  loss  of  pro- 
ductive land. 
Great  stress  was  laid  by  some  of  the  witnesses  who  gave 
evidence  before  the  Committee  of  the  House  of  Lords  on  River 
Conservancy  as  to  the  advantage  of  embanking  to  prevent 
floods,  as  against  deepening  the  channel ; but  it  is  submitted 
that  the  two  works  should  go  on  together.  By  dredging  out  and 
deepening  the  channel,  the  level  of  the  water  is  kept  lower,  and 
there  is  less  risk  consequently  of  flooding  from  a breach  of 
banks,  while  at  the  same  time  material  is  provided  for  the 
formation  of  the  protecting  banks. 
With  the  view  of  equalising  the  flow  of  the  upland  water  as 
much  as  practicable  throughout  the  year,  it  is  desirable  that,  while 
provision  is  made  for  getting  rid  of  the  rainfall  as  rapid ly 
as  possible  in  times  of  flood,  the  regulation  of  the  water- 
supply  should  be  aimed  at,  rather  than  the  mere  voidance  of 
the  water.  If  all  the  water  due  to  the  winter  rainfall  is  dis- 
charged at  once,  the  lands  drained  would  probably  suffer  far 
more  loss  from  droughts  in  summer  than  ever  the  floods  would 
have  occasioned. 
Water  is  required  not  only  for  the  growth  of  vegetation,  but 
for  drinking  and  other  purposes,  and  may  be  made  valuable  as 
a mechanical  aid  in  carrying  on  the  work  of  the  farm.  Water 
is  obtained  for  drinking  principally  from  wells  and  springs, 
which  are  fed  from  supplies  stored  up  in  the  pores  of  tlie 
material  composing  the  crust  of  the  earth  and  in  the  cavities 
of  rocks,  and  a certain  proportion  of  the  rainfall  must  be  allowed 
to  soak  into  the  ground  during  wet  weather  to  feed  them,  and 
to  maintain  a constant  stream  of  water  down  the  rivers  and  their 
tributaries  during  the  dry  season.  In  chalk  districts  and  where 
the  rocks  are  porous  and  absorbent,  the  greater  portion  of  the 
rainfall  is  taken  up  in  this  way,  and  the  absence  of  streams  in 
a chalk  district  is  thus  accounted  for.  In  lime  and  sandstone 
districts  this  condition  of  the  substrata  might  be  taken  advan- 
tage of  much  more  largely  than  it  is,  by  carrying  shafts  through 
the  upper  impervious  strata  to  the  lower  porous  rock,  and  thus 
causing  these  to  act  to  a certain  extent  as  flood  regulators,  and 
providing  more  abundant  and  constant  supplies  to  the  springs. 
There  are  also  many  valleys  where,  at  small  expense,  embank- 
ments could  be  thrown  up  and  reservoirs  formed,  which  could 
be  made  available  for  the  water  supply  of  villages  and  farm- 
steads, and  at  the  same  time  frequently  could  be  made  orna- 
mental adjuncts  to  parks  and  pleasure-grounds.  The  embank- 
ments for  such  reservoirs  need  not  necessarily  be  of  great  height, 
but,  where  a valley  is  long  and  continuous,  could  be  made  in 
