To  Make  Wood  A  Impost  Incombustible,
Well-seasoned  wood  is  steeped  for  24
hours  in  a  solution  of  water-glass  in
three  times  its  volume  of  water.  It  is
then  dried  in  the  air  for  a  few  days,  and
the  soaking  for  24  hours  in  the  same
solution  and  drying  repeated  several
times.  It  is  finally  thoroughly  dried
and  given  a  coat  of  a  mixture  of  1  part
of  fresh  cement  and  4  parts  of  the  above
solution  of  water-glass.  Not  too  much
of  this  last  mixture  must  be  prepared
at  one  time,  as  it  would  become  solid


and  therefore  useless.  The  first  coat  is
allowed  to  dry  for  24  hours.  The  wood
receives  then  a  second  but  somewhat
thicker  coat  of  cement  and  water-^lass,
and,  when  dry,  a  final  coat  of  ordinary
water-glass,  which  gives  a  smooth,  glassy
appearance  to  it.  Wood  treated  m  the
above  manner  will  not  ignite  even  in  a
strong  fire,  as  has  been  yiroved  by  ex-
periments on  a  large  scale.  This  treat-
ment protects  it  also  against  the  attacks
of  insects  and  rotting.
To  Dry  Damp  Walls.  The  old  plas-
ter is  first  removed  from  the  walls  and
the  joints.    Slabs  consisting  of:

Bosin 3  parts.
Tar 2     *'

Asphaltum 5      "

Quartz  sand 6     *'

are  then  prepared.  The  smooth  sur-
faces of  these  slabs  are  coated  with  a
lacquer  consisting  of:

Oil  of  turpentine 2  parts.
Shellac 1  part.
Spirit  of  wine 4  parts.
and  then  strewed  with  sharp  sand^  while
the  rough  surface  of  the  plates  is  fast-
ened to  the  w^all  with  a  mortar  consist-
ing of:

Sand 4  parts.
Hydraulic  lime 2      "

Portland  cement 1  part.
The  joints  are  filled  in  with  a  putty
consisting  of:

Bosin 6  parts.
Asphaltum 1  part.
Poufdered  lime 2  parts.
