94 
for preserving- works. Capacity of plant. Cost of plant. Cost of op- 
erating. 
I may be permitted to quote from the recent and very instructive re- 
port on the preservation of timber, made in 1885, by a committee of the 
American Society of Engineers, after a careful and protracted examina- 
tion of the subject : 
"In view of the differing cost of the various antiseptics used, and of the price of 
timher in this country, where it is still much cheaper than in Europe, we helievethat 
the method to he selected for preserving wood, if any, depends almost wholly upon its 
proposed subsequent exposure. 
" If the timber is to be exposed, in sea water, to the attacks of the Teredo navalis and 
Limnoria terebrans, there is but one antiseptic which can be used with our present 
knowledge. This is creosote or 1 dead oil,' and the amount of it necessary depends 
upon the activity of the Teredo, or rather upon the length of time during the year 
when the temperature of the water renders them active. 
"In our northern harbors, probably 10 to 12 pounds of creosote to the cubic foot of 
timber are sufficient, but in southern seas it is probably necessary to inject from 14 
to 20 pounds per cubic foot. 
"Whether it will pay to do this depends upon so many local circumstances in each 
case that this cannot well be discussed here. If the timber is to be exposed in a very 
wet situation, creosoting is also the best process to use. It will cost from $10 to $20 
per 1,000 feet, b. m v or 35 to 60 cents per tie. 
"The selection of the oil, as well as the quantity, is of importance. It was for- 
merly believed that the antiseptic properties of dead oil arose from the presence of car- 
bolic and cresylic acid, but a very able paper by Mr. S. B. Boulton, the leading au- 
thority on creosoting in England, read before the British Institution of Civil Engi- 
neers in 1884, seems to establish the fact that the preserving properties of dead oil, 
aside from the mechanical effect in keeping out moisture, are chiefly due to 'acri- 
dine,' or one of the alkaloids or bases now known to exist in creosote oils. 
" If the exposure is to be that of a railroad tie, creosoting is doubtless the most 
perfect process to use; but in view of the expense, it may be preferable to use a 
cheaper process, dependent somewhat upon the location, as away from the seaboard 
creosote is not available, and transportation is expensive." 
" Sleepers of Baltic Fir, unprepared, 9 feet long and 10 x 5 inches, generally cost, in 
England, about 90 cents each, unloaded, grooved, and piled; and creosoting adds 
about 24 cents to this. So that the sleeper costs about $1.14 ready to go into the 
track, and is there laid with a chair under the double-headed rail, so that the latter 
does not cut into the wood. These sleepers, therefore, last 18 to 20 years, while in 
this country they would probably be cut into by our foot-rail in from 12 to 16 years ; 
and, moreover, as the first cost of our ties, of corresponding timber, say hemlock or 
mountain pine, is only from 25 to 35 cents, we cannot afford to spend an equal sum in 
preserving them ; and creosoting is notoriously more expensive here than in England. 
"With our present knowledge, and as a result of this investigation, we believe 
that Burnettizing is the advisable process to use for ties at present in this country. 
This, if w r ell done (and it is nearly useless to do it otherwise), will cost 20 to 25 cents 
per tie, and a discussion of the economical results to be expected therefrom will be 
found in Appendix No. 17. 
" Good results may be accomplished with sulphate of copper, but not only does this 
salt render wood brittle (more so, it is believed, than chloride of zinc), but as the 
copper attacks iron vessels, its use necessitates preserving cylinders of copper, and 
requires an expensive plant. 
" The great defect of all mineral salts is that they are easily soluble hi water, and 
so wash out in time, and leave the timber unprotected. Hence the many attempts to 
patent some method of retaining them in the wood. What these may be worth must 
