49 WESTERN YELLOW PINE IN -ARIZONA AND NEW MEXICO. 
TABLE 22.—Comparative results of preservative treatment of western 
‘ yellow pine. 












Esti- Esti- Annual 
Pues mated | mated | Esti- | ,nnual | Saving 
Species. Character of treatment. and & cost of | costof | mated east due to 
ee sie treat- | polesin | life. : treat- 
Ber DoS Sement: place. ment.1 
Years 
\ESUS aT NEL UG Wy |) WIStRee WE0 = eo Se ocbeccd)ecee cceene|ceeccocece $8. 00 O29 4555 28 See 
pine 
IDO aa oe eae Brush treatment.....-| 5 $0. 25 8.25 6 1, 63 $1.31 
DG. eae Open-tank treatment... 60 1.90 9.90 20 79 205 
Redicedargeeess.2: ey amen Siem Ie De eee ae bauriateatarea| Sem eeee ori 9. 50 10 R23)|5 3 eee 
DOR nse se ees Brush treatment. ...-- Gg 30 9. 80 13 1.04 .19 
Doss ree ee Open-tank treatment. . 40 1.35 10. 85 20 - 87 .36 
(1+R)2Xz 
1 Annual saving computed from formula a=p (4R)a—y- @= annual saving; b=amount of initial 
expenditure; c=rate of interest expressed decimaily. 
A study of Table 22 leaves no reasonable doubt as to the economy 
of the preservative treatment of western yellow pine poles when only 
the one species is considered. In the comparison with red cedar, 
moreover, it is seen that under the conditions assumed the greater 
economy will result from the use of pine poles treated with creosote 
by the open-tank method. 7 
Crossties may be considered in a hke way. The average cost of all 
western yellow pine ties purchased by the steam railroads in 1908 
was 51 cents per tie. An allowance of 10 cents for placement, 55 
cents for treatment with 24 gallons of creosote, and 13 cents for treat- 
ment with one-half pound of zine chloride per cubic foot, gives the 
following cost for the tie in place in the track: 
Dintreated: 2 be a 22.0 ee eee SE eo oes Sea ee $0.61 
CEO SOC ea I Te gS 1.16 
FT CCW OT UGS ee as a ee gs oe RS 74 
Assuming a life of 8 years for the untreated tie, and figuring in- 
terest at 5 per cent, it is seen that only 7 years’ service of the creosoted 
tie will effect an annual saving of 2 cents per tie, while but 4 years’ 
service of the tie treated with zinc chloride is necessary to effect 
economy. 
Whether or not greater economy will result from the use of other 
species can only be determined for each specific case. Under certain 
conditions untreated redwood ties might be more desirable; in others 
creosoted Douglas fir. Again, conditions may arise where a red 
cedar tie will be more desirable than one of western yellow pine. 
Wherever it is decided to use western yellow pine, however, the ad- 
vantages of a properly applied preservative treatment can not be — 
disputed. 
eld 


