16  Experimental  ^Legislation
the  age,  again,  of  Free  Public  Libraries,  the
practicability  and  extreme  usefulness  of  which
were  first  established  in  Salford  and  Manchester.
When  once  possessed  of  local  habitations,  such
institutions  will,  it  may  be  hoped,  have  long
careers;  but  bricks  and  mortar  are  usually  requisite ­
  to  give  perpetuity  to  a  social  experiment.
When  thus  perpetuated,  each  kind  of  institution
marks  its  own  age  with  almost  geologic  certainty.
From  the  times  of  the  Saxons  and  the  Normans
we  can  trace  a  series  of  strata  of  institutions  superposed ­
  in  order  of  time.  The  ancient  Colleges  of
Oxford  and  Cambridge,  the  mediaeval  Guilds
surviving  in  the  City  Companies,  the  Grammar
Schools  of  the  Elizabethan  age,  the  Almshouses
of  the  Stuart  period,  the  Commercial  Institutions
of  Queen  Anne’s  reign,  and  so  on  down  to  the
Free  Libraries  and  Recreation  Palaces  of  the
present  day.  Even  styles  of  architecture  are
evolved  by  successful  innovation—that  is,  experiment ­
  followed  by  imitation,  and  this  was  never
more  apparent  than  in  the  imitation  which  has
followed  upon  Sir  Joseph  Paxton’s  grand  experiment ­
  at  the  Exhibition  of  1851.*
Now,  my  contention  is  that  legislators  ought,
in  many  branches  of  legislation,  to  adopt  confessedly ­
  this  tentative  procedure,  which  is  the
*  I  do  not  remember  to  have  seen  the  importance  of  this  imitative
tendency  in  social  affairs  described  by  any  writer,  except  the  French
Engineer  and  Economist,  Dupuit,  who  fully  describes  it  in  one  of  his
remarkable  memoirs,  printed  in  the  “  Annales  des  Ponts  et  Chaussees.”