88 
pose, if the necessary time arid money can be spared to thoroughly dry 
the timber after impregnating it with zinc chloride, and before injecting 
the oil. 
COST OF PRESERVATION. 
In order to make a fair comparison of the cost of treatment with the 
different antiseptics now in use, I will assume that the same kind of 
timber and the same form, viz, that of hard railroad ties, each contain- 
ing 3.5 cubic feet, is to be treated, and that the quantity of antiseptic 
solution used, and the strength of the solution, are to be in conformity 
with the best practice, as developed by experience in plants of given 
size. 
a. Creosoting. — Assuming that two injection cylinders are to be used, 
each 100 feet long and 6 feet in diameter, the total volume of each 
cylinder will be 2,800 cubic feet, and it will have a capacity of nearly 
1,400 cubic feet of timber (making allowance for volume of cars and 
interstices). The total plant required would cost, say, $80,000. If it 
takes twelve hours for a run, 5,600 cubic feet, or 1,600 ties (of 3.5 cubic 
feet each), can be treated per day; or, say, 500,000 ties, or 1,750,000 
cubic feet, can be treated in a year. 
Taking the interest on capital (including repairs and renewal) at 10 
per cent., the item of interest on plant will be $8,000, or 1.6 cents per tie. 
Assuming the proper quantity of dead oil at 7 pounds per cubic foot, 
or 24.5 pounds per tie, and the cost of the oil at 0.8 cents per pound, 
the cost of material will be 19.6 per tie. 
The cost of labor and fuel chargeable to treatment alone, judging 
from the accounts kept at Las Vegas, may be taken at about $15 per 
run, or, as 400 ties are treated at once, 3.75 cents per tie, or 1.07 cents 
per cubic foot of timber. The total cost of creosoting a tie would be, 
therefore : 
Per tie. 
Per cubic 1 
foot. 
Interest on capital.. 
Material 
Labor and fuel 
Cents. 
1.6 
19.6 
3. 75 
Cents. 
0.46 
5.6 
1.07 
Total 
25. 00 
7.1 
The cost of transporting the ties to and from the works would of 
course have to be added, and profit, if the work is done by contract.* 
I may mention, that the above price for the dead oil is smaller than 
has been generally assumed, this because lately I have been offered 
dead oil at ^ of a cent per pound. At that price the cost of creosoting 
would be only about 144 cents per tie. 
If piles or timber were to be creosoted and impregnated with 20 
pounds per cubic foot, it would take about sixty hours for a run, and the 
* See note of cost of creosoting in France on page 78. 
