180 
VARIETIES. 
Kind  of  Timber. 
No.  of 
sills 
operated 
upon. 
Average 
pounds 
gained 
per  sill. 
Average 
pounds 
gained 
percu.  ft. 
Average 
gallons 
per  sill. 
Average 
gallons 
per 
cubic  ft. 
IVTfiYimnrvi 
1TX  (X  A.  1  LU  U  IjLI 
gallons  per 
cubic  foot. 
White  oak, 
1038 
8-9 
3-1 
1-8 
0-62 
1-87 
Rock  oak, 
96 
11-5 
3-9 
2-38 
0-78 
1-87 
Red  oak, 
153 
10-0 
3-9 
2-04 
0-78 
1-70 
Black  oak, 
903 
9  6 
3*6 
1-87 
0-72 
2-64 
Chestnut, 
144 
6-1 
3-0 
1-20 
0-60 
1-87 
Hemlock, 
617 
75 
2-6 
1-51 
0-52 
1-87 
After  the  lapse  of  seven  days  the  increase  of  weight  in  the  oaks  appeared 
to  be  checked.  The  chestnut  and  hemlock  being  slower  in  absorption 
would  require  14  days  to  complete  their  saturation.  These  facts  ascer- 
tained by  preliminary  experiments,  account  for  the  discrepancy  in  the  above 
table  in  the  averages  of  these  classes  of  timber. 
The  writer  encountered  some  difficulty  in  estimating  the  exact  quantity 
(liquid  measure)  of  the  solution  absorbed,  as  the  amount  of  sap  displaced 
in  the  green  timebr  is  considerable,  and  consequently  the  estimate  of  the 
quantity  of  the  solution  absorbed  from  the  weight  gained  would  be  incor- 
rect. After  a  careful  investigation  it  was  found  that  the  increase  in  the 
measure  of  the  solution  received  by  the  sill,  averaged  70  per  cent,  over  and 
above  the  quantity  called  for  by  the  gain  in  weight  of  the  sill. 
This  increment  is  taken  into  the  calculation  of  the  gallon  columns  of  the 
table. 
In  order  to  ascertain  the  relative  extent  or  degree  of  absorption  of  the 
popular  solutions  by  the  different  classes  of  timber,  the  writer  caused  to  be 
divided  into  three  equal  parts,  a  rock  oak,  a  white  oak,  and  hemlock  sill, 
each  as  thus  divided  was  placed  vertically  in  separate  casks,  which  were 
filled  by  the  solutions. 
Cask  with  the  chloride  of  zinc  one  pound  to  10  gallons  of  water. 
"         blue  vitriol  one  pound  to  \2\  gallons  of  water. 
"        pyrolignite  of  iron  (density  1-101),  1  part  of  pyrolignite  to  6  of  water. 
After  the  duration  of  one  week 
The  white  oak  stick  in  the  cloride  of  zinc, 
'«  "       blue  vitriol, 
"  "       pyrolignite  of  iron, 
The  rock  stick  in  the  chloride  of  zinc, 
"  "       blue  vitriol, 
"  "       pyrolignite  of  iron, 
The  hemlock  stick  in  chloride  of  zinc, 
"  "    blue  vitriol, 
il  11    pyrolignite  of  iron, 
The  blue  vitriol  is  absorbed  more  readily  by  the  hemlock,  and  the  oaks 
prefer  the  pyrolignite. 
For  the  impregnation  of  the  heavy  timbers  used  upon  bridges  and  other 
structures,  a  large  wooden  cistern  4£  feet  in  diameter  in  the  clear,  and  27 
gained  in  weight    6*8  per  cenl 
n  n  tj.Q  << 
"  "  io-7  " 
it  it  ^.g  a 
<<  it  4.g  << 
"  "  5-6  " 
it  ll  ij.y  (« 
it  (i  1Q.1  ti 
ll  ll  *J.Q  tt 
