VARIETIES. 
181 
feet  deep,  was  constructed  of  3-inch  seasoned  white  pine  plank,  tightly 
caulked  in  the  seams,  and  bound  with  iron  hoops  ;  two  courses  of  3-inch 
plank  were  laid  transversely  and  firmly  secured  at  the  bottom  of  the  cis- 
tern. 
This,  when  finished  by  the  carpenters,  we  sunk  into  the  ground  until  the 
top  edge  stood  three  feet  ab>ve  the  surface.  A  hoisting  crane  is  used  in 
lifting  the  timber ;  the  sticks  being  placed  in  a  vertical  position  in  the  cis- 
tern, which  should  always  be  kept  filled  to  its  top  edge  with  the  solution — in 
this  way,  a  pressure  of  a  column  27  feet  in  height  is  maintained  at  the  butt 
end  of  the  timber. 
The  following  table  shows  the  quantity  of  solution  introduced  into  a 
cubic  foot  of  the  different  woods — the  solution  consisting  of  one  part  of  py- 
rolignite  of  iron  and  six  parts  water  : 
Kind  of  timber. 
Number  of 
cubic  feet. 
Average  absorption 
per  cubic  foot. 
Maximum  absorption 
per  cubic  foot. 
White  oak, 
Rock  oak, 
Red  oak, 
Black  oak, 
White  pine, 
542 
833 
39 
67 
166 
0-53  gallon. 
0-71  <; 
093  « 
0-  85  " 
1-  10  « 
2-72  gallons. 
2-04  " 
1-87  " 
1-  45  " 
2-  04  " 
Timber  freshly  cut  will  receive  the  solutions  more  readily  than  when  dry 
— some  pieces  of  white  oak  which  had  been  cut  three  months,  absorbed  per 
cubic  foot  76  per  cent,  more  than  the  same  description  and  sizes  of  timber 
which  had  been  twelve  months  felled. 
It  was  also  observed  that  in  pushing  some  freshly  cut  beams  with  a  sud- 
den downward  force  into  the  cistern,  the  sap  would  appear  on  the  top  of 
the  beam  often  in  quantities  to  fill  a  wineglass. 
These  facts  confirm  the  opinions  of  Boucherie,  and  show  that  the  drying 
and  seasoning  of  timber  to  prepare  it  for  impregnation  is  an  unnecessary 
waste  of  labor. 
The  expense  of  impregnating  railway  timber  with  the  process  advocated 
by  the  writer  is  but  trifling. 
The  labor  required  is  involved  only  in  lifting  and  carrying  the  timber, 
and  to  this  must  be  added  the  cost  of  the  solutions  absorbed.  A  statement 
of  the  cost  of  preserving  sills  with  the  usual  antiseptics  is  here  given. 
Chloride  of  Zinc. 
In  proportions  used  by  Brunei,  viz  :  one  pound  to  10  gallons  of  water — cost  ' 
of  chloride  of  zinc  9  cents  per  pound. 
Labor  at  tank,  lifting  and  carrying  the  sills,  1-0  cent 
Solutiou  absorbed,  2  gallons,  1-8 
Cost  per  sill,  2.8  cents. 
Blue  Vitriol. 
In  the  proportions  adopted  by  Boucherie,  viz:  one  pound  to  12|  gallons  of 
water,  cost  of  blue  vitriol  14  cents  per  pound. 
Labor  at  tank,  &c,  1-0  cent. 
Solution  absorbed,  2-24 
Cost  per  sill, 
3-24 
