Our  Canaries 
6i 
sive  and  heated,  and  may  even  cause  a  feeling  of  sickness  if  the  deficiency  has 
been  very  great.  The  ingress  of  fresh  air  should  be  increased  until  the  air  is 
tolerably  pure  and  not  overheated  when  the  house  is  unlocked  for  the  first  time 
in  the  morning  after  being  closed  all  night. 
FRESH   AIR  WITHOUT  DRAUGHTS. 
To  attain  this  object  it  is  necessary  to  have  some  means  of  regulating 
the  ventilation  to  suit  the  varying  conditions  of  weather  prevailing  outside.  It 
will  be   obvious   to  all  that  during  the  hot 
•4^1.        I   summer  months  a  far  greater  amount  of  air  will 
^   be  necessary  to  keep  the  place  cool  and  fresh 
as  would  suffice  in  the  winter  time. 
It  is,  therefore,  important  to  have  the 
ventilating  orifices  fitted  with  sliding  shutters, 
which  can  be  pushed  to  and  fro  to  open  or 
close  the  aperture,  and  thus  increase  or 
decrease  the  supply  of  air  in  a  moment,  to 
suit  every  passing  need.  Much  as  we  insist 
upon  the  necessity  for  doing  this  part  of  the 
work  thoroughly,  we  must  also  impress  upon 
one  and  all  the  absolute  necessity  of  guarding 
against  cold  draughts  in  all  weathers.  Cold  of 
itself  will  very  rarely  do  any  harm  to  a  healthy 
bird,  but  it  must  be  generally  distributed  and 
not  dispensed  in  tiny  cutting  streams,  as  it 
were,  or  in  cold  currents  that  flow  over  the 
birds  when  they  are  at  rest,  and  chill  them  to 
the  marrow.  The  apertures  for  the  ingress 
and  egress  of  air  must  be  so  arranged  as  to 
prevent  as  far  as  possible  any  strong  current 
passing  direct  from  one  to  the  other ;  and 
again,  the  cages  or  perches  for  roosting  at  night  must  be  so  arranged  as  to 
be  out  of  the  path  of  any  such  current  if  it  should  be  temporarily  set  up  by  the 
direction  or  force  of  the  wind  outside. 
TOBIN'S    APPARATUS    FOR  IM 
PROVED  VENTILATION. 
A.  The  Wall. 
B.  Vsntilating  Pipe. 
TOBIN'S   SYSTEM   OF  VENTILATION. 
A  system  of  ventilation  by  means  of  pipes  passing  through  the  wall,  which 
worked  on  the  syphon  principle  and  insured  perfect  ventilation  with  absolute 
freedom  from  draughts,  was  dealt  with  some  years  ago  in  the  leading  Press 
of  this  country,  and  was  known  as  Tobin's  system  of  ventilation.  The  sketch 
given  here  shows  the  principal  features  of  the  system, 
