T A 
 
 424 
 Xs 
 
 Issued June 12, 1911. 
 
 U. S. DEPARTMENT OF AGRICULTURE, 
 
 FOREST SERVICE— BULLETIN 84. 
 
 HENRY S. GRAVES, Forester. 
 
 PRESERVATIVE TREATMENT OF POLES. 
 
 COMPILED BY 
 
 WILLIAM H. KEMPFER, 
 
 FOREST ASSISTANT. 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING OFFICE. 
 
 1911. 
 
 • r l^l 
 
Glass 'A 4^ 
 
 Book 
 
/; 
 
 Issued June 12, 10 11. 
 
 U. S. DEPARTMENT OF AGRICULTURE, 
 
 FOREST SERVICE— BULLETIN 84 
 
 HENRY S. GRAVES, Forester. 
 
 PRESERVATIVE TREATMENT OF POLES. 
 
 COMPILED BY 
 
 WILLIAM H. KEMPFER, 
 
 FOREST ASSISTANT, 
 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING OFFICE, 
 
 1911. 
 

 ^ 
 
 LETTER OF TRANSMITTAL. 
 
 U. S. Department of Agriculture, 
 
 Forest Service, 
 Washington, D. C, October 15, 1910. 
 Sir: I have the honor to transmit herewith a manuscript entitled 
 "Preservative Treatment of Poles," compiled by William H. Kempfer, 
 Forest Assistant, and to recommend its publication as Bulletin 84 of 
 the Forest Service. This bulletin is compiled in part from previous 
 publications of the Forest Service, namely, Circulars 103, "Seasoning 
 of Telephone and Telegraph Poles," by Henry Grinnell; No. 104, 
 "Brush and Tank Pole Treatments," by Carl G. Crawford; No. 136, 
 "Seasoning and Preservative Treatment of Arborvitse Poles," by 
 C. Stowell Smith; and No. 147, "Progress in Chestnut Pole Preser- 
 vation," by Howard F. Weiss. It presents, in addition, results of 
 more recent experiments, especially those of O. T. Swan, Forest 
 Assistant, who is also the author of the design for open-tank pole- 
 treating plants. The inspection report contained in the Appendix 
 was made by the compiler. 
 
 Respectfully, Henry S. Graves, 
 
 Forester. 
 Hon. James Wilson, 
 
 Secretary of Agriculture. 
 
 U)N 
 
CONTENTS. 
 
 Page. 
 
 Introduction 7 
 
 General principles of wood preservation 7 
 
 Forest Service investigations 8 
 
 Resume of projects : 9 
 
 Results of seasoning tests. . . : 10 
 
 Loss of weight 10 
 
 Rate of seasoning 11 
 
 Factors affecting seasoning 11 
 
 Checking 12 
 
 Shrinkage 13 
 
 Brush method of treating poles 13 
 
 Open-tank process of treating poles 14 
 
 Manner of application 15 
 
 Duration of treatment 15 
 
 Temperature of hot bath 16 
 
 Influence of rate of growth ; , . . 16 
 
 Influence of moisture '. . 16 
 
 Influence of season of cutting 17 
 
 Influence of soaking in water 17 
 
 Advantages and limitations of the open-tank process 17 
 
 Results of treatments, by species _ 18 
 
 Chestnut ." 18 
 
 Brush treatments 18 
 
 Tank treatments 19 
 
 Southern white cedar 20 
 
 Northern white cedar 20 
 
 Brush treatments 21 
 
 Tank treatments 21 
 
 Western red cedar 22 
 
 Brush treatments 22 
 
 Tank treatment with creosote 23 
 
 Tank treatment with zinc chlorid 25 
 
 Other treatments 26 
 
 Western yellow pine 26 
 
 Brush treatments 26 
 
 Tank treatments with creosote 27 
 
 Tank treatments with zinc chlorid 28 
 
 Tank treatment with creosote and zinc chlorid 28 
 
 Tank treatments with crude petroleum 28 
 
 Lodgepole pine 29 
 
 Loblolly pine 29 
 
 Cypress 30 
 
 3 
 
CONTENTS. 
 
 Page. 
 
 Design and operation of pole-treating plants 30 
 
 Experimental plants 30 
 
 Commercial plant for butt treatments 31 
 
 Cost of operation 32 
 
 Design of plant for treatment of the entire pole 33 
 
 Cost of pole treatments 34 
 
 Tank treatment with creosote 34 
 
 Tank treatment with zinc chlorid " 34 
 
 Tank treatment with crude petroleum 35 
 
 Brush treatment 35 
 
 Increased life afforded by preservative treatment 35 
 
 Financial saving 36 
 
 Relation of preservative treatments to pole specifications 38 
 
 Growth and form of poles 38 
 
 Summary 39 
 
 Appendix. 
 
 Report of inspection of experimental poles 41 
 
 Discussion of results .' 44 
 
 Southern white cedar poles 44 
 
 Chestnut poles 45 
 
 Irregularities in results 45 
 
 Height of decay above ground line 45 
 
 Deterioration shown by change of grades 46 
 
 Analysis of preservatives used in the treatment of poles set in the Augusta- 
 Savannah and Helena-Meldrin lines 46 
 
 Preservative sold as Avenarius Carbolineum 47 
 
 Preservative sold as S. P. F. Carbolineum 47 
 
 Preservative sold as Spirittine 47 
 
 Coal tar creosote 48 
 
 Preservative sold as Imperial Wood Preservative 48 
 
 Preservative sold as Creolin 48 
 
 Detailed tables and curves showing rate of seasoning of poles 49 
 
 Table 27. — Rate of seasoning of southern white cedar poles at Wilmington, 
 
 N. C 49 
 
 Table 28. — Rateof seasoning of chestnut poles at Pisgah, N. C 50 
 
 Table 29. — Rate of seasoning of chestnut poles at Dover, N.J 50 
 
 Table 30. — Rate of seasoning of chestnut poles at Thorndale, Pa 51 
 
 Table 31. — Rate of seasoning of chestnut poles at Parkton, Md 51 
 
 Table 32. — Rate of seasoning of northern white cedar poles at Escanaba, 
 
 Mich 52 
 
 Table 33. — Rate of seasoning of western red cedar poles at Los Angeles, 
 
 Cal 53 
 
 Table 34. — Rate of seasoning of western yellow pine poles at Northfork, 
 
 Madera County, Cal 54 
 
ILLUSTRATIONS. 
 
 Plate I. Fig. 1. — Treating southern white cedar by -brush method. Fig. 2. — 
 
 Treating chestnut poles by open-tank method 16 
 
 II. Fig. 1. — Untreated pole of southern white cedar. Fig. 2. — Creosoted 
 
 loblolly pine pole after eighteen years' service 24 
 
 III. Fig. 1 — Cross section of the butt of a treated western red cedar pole. 
 
 Fig. 2. — Cross section of the butt of a treated yellow pine pole 24 
 
 IV. Cross section of a small loblolly pine pole treated with creosote 28 
 
 TEXT FIGURES. 
 
 Fig. 1. Progress of decay in an untreated pole 12 
 
 2. An S iron driven in the butt of a pole _ 13 
 
 3. Open tank and gin pole used in experimental pole treatments 31 
 
 4. Plan of a commercial plant for the butt treatment of poles 32 
 
 5. Plan of a commercial plant where the entire pole is to be treated 32 
 
 6. Diagram showing condition of experimental poles 42 
 
 7. Rate of seasoning of southern white cedar poles, Wilmington, N. C. . . 49 
 
 8. Rate of seasoning of chestnut poles, Parkton, Md 52 
 
 9. Rate of seasoning of northern white cedar poles, Escanaba, Mich 52 
 
 10. Rate of seasoning of western red cedar poles, Los Angeles, Cal 53 
 
 11. Rate of seasoning of western yellow pine poles, Madera County, Cal. . . 55 
 
 5 
 
PRESERVATIVE TREATMENT OF POLES. 
 
 INTRODUCTION. 
 
 Users of poles in all parts of the country are alive to the necessity 
 of obtaining increased length of service from their poles. This 
 interest has been stimulated by the tendency toward advancing 
 prices of forest products and apprehension with regard to the future 
 supply. Realizing the need for more information along this line, the 
 Forest Service a number of years ago began investigations of meth- 
 ods for prolonging the life of poles, and during the past four years a 
 number of circulars a giving the progress of experiments have been 
 published. 
 
 This bulletin aims to sum up the results that have already been 
 published, and to present additional data and information, gained by 
 the more recent investigations. 
 
 GENERAL PRINCIPLES OF WOOD PRESERVATIONS 
 
 Except in very warm and moist climates, a pole which is placed on 
 skids and allowed to become air dry does not decay, because it does not 
 contain sufficient moisture to support the growth of fungi and wood- 
 boring insects, which are the causes of decay. However, if the pole is 
 set, that portion of it in contact with the soil will absorb moisture 
 until conditions favorable to decay are restored. To prevent decay 
 in timber exposed to the soil or moist air, the wood substance, which 
 
 a The Bureau of Entomology also has published results of investigations of damage 
 to forest products by insects, in which it is shown that injury to pole timber and the 
 commercial and utilized product by wood-boring insects contributes to direct deteri- 
 oration and subsequent decay, and that much of this loss can be prevented by proper 
 methods of management and treatment with preservatives. Attention is called to 
 the following publications: Insect Injuries to Forest Products, by A. D. Hopkins, 
 Bureau of Entomology, Yearbook, Department of Agriculture, 1904, pp. 381 to 398. 
 Bulletin 58, Part V, Some Insects Injurious to Forests, Insect Depredations in North 
 American Forests and Practical Methods of Prevention and Control , by A . D. Hopkins, 
 in charge of Forest Insect Investigations, December, 1909, pp. 64 to 67, 79 to 81, and 
 84. Bulletin 94, Part I, Damage to Chestnut Telephone and Telegraph Poles by 
 Wood-boring Insects, by Thos. E. Snyder, Agent and Expert, Bureau of Entomology. 
 
 The references to insects in this bulletin are based to a large extent on information 
 supplied by the Bureau of Entomology. 
 
 b For a more complete discussion of this subject, see Forest Service Bulletin 78, 
 "Wood Preservation in the United States." 
 
 7 
 
8 PRESERVATIVE TREATMENT OF POLES. 
 
 is the food of the decay-producing organisms, must be rendered inca- 
 pable of supporting fungous growth. In commercial timber- treating 
 practice this is accomplished by the injection of antiseptics. 
 
 It is not usually practicable even with the best methods of treat- 
 ment, except in the case of very porous woods, to impregnate the 
 wood throughout. The value of the treatment consists largely in creat- 
 ing an outer protective envelope around the untreated interior wood. 
 The thickness necessary for this envelope to give efficient protection 
 depends on the use to which the timber is to be put. In general, the 
 antiseptic should penetrate deep enough to prevent exposure of the 
 untreated wood by abrasion, checking, or other action. Since the 
 liability of the protective zone to destruction from mechanical 
 causes or by gradual volatilization of the oil is dependent on its 
 thickness, or, in other words, on the quantity of preservative ab- 
 sorbed and the depth of penetration, it is reasonable to assume that 
 within certain limits the added life of the timber due to treatment 
 with a given preservative will be in approximate ratio to the amount 
 of penetration and absorption of the preservative. 
 
 FOUEST SERVICE INVESTIGATIONS. 
 
 Knowledge of the results of creosote treatment is based largely on 
 treatments made by the pressure method, using from 8 to 12 pounds 
 or more of creosote to the cubic foot of timber. In spite of the 
 excellent results that have been obtained by such treatment, it has 
 been but little used by pole consumers, except in certain parts of the 
 South, where exceptionally rapid dec a}'' makes preservative treat- 
 ment imperative. The chief hindrances to a more general adoption 
 of creosote treatment for poles have been the high cost of the treat- 
 ment and the expense of transporting the timber to a distant point 
 for treating. The investigations of the Forest Service. have, there- 
 fore, been concerned mostly with cheaper and simpler methods, and 
 with treatments winch could be applied locally without the erection 
 of elaborate and expensive plants. Much attention has been given 
 to the seasoning of poles, since proper seasoning not only prepares 
 poles to receive the preservative treatment, but, under certain con- 
 ditions, may be in itself a means of increasing their durability. The 
 treating investigations proper have followed three general lines: 
 
 (1 ) Testing the efficiency of various wood preservatives and of 
 applications of varying amounts, 
 
 (2) The developing of a method for impregnating the portion of a 
 pole most subject to decay — the butt. 
 
 (3) Designing of inexpensive apparatus suited to the treatment of 
 poles in small quantities, or in such quantities as local needs may 
 require. 
 
KESTJME OF PEOJECTS. 9 
 
 In these investigations much assistance has been received from a 
 number of electrical companies, which have placed poles at the dis- 
 posal of the Forest Service for the tests and contributed funds toward 
 paying the cost of the investigations. The experimental poles, in 
 most instances, have been placed in service by the companies inter- 
 ested, and in such a manner that durability records may be obtained 
 from them. These records will prove a source of further information 
 on the efficiency of the treatments. 
 
 RESUME OF PROJECTS. 
 
 In 1902 field investigations were begun in cooperation with the 
 American Telephone and Telegraph Company. The project as finally 
 developed included chestnut, southern white cedar, and northern 
 white cedar a poles, experiments with the first being conducted in 
 North Carolina, New Jersey, Pennsylvania, and Maryland, with the 
 second in North Carolina, and with the third in Michigan. Another 
 project undertaken in cooperation with a number of pole-using com- 
 panies in California, 6 included a study of the treatment of western 
 yellow pine and western red cedar poles. Further sources of the 
 information were afforded by treatments of lodgepole pine poles at 
 a plant erected by the Forest Service on the Sopris National Forest 
 at Norrie, Colo., and of loblolly pine poles at a plant designed by the 
 Forest Service and erected by the North Louisiana Telephone Com- 
 pany at Winnfield, La. In addition to the tests in seasoning and 
 treating, a number of experimental pole lines have been set, in which 
 poles treated with various preservatives have been placed alongside 
 of untreated ones in order that their durability might be compared. 
 
 a This tree ( Thuja occidentalis) has in earlier publications of the Forest Service been 
 referred to under the common name of arborvitse. It is, however, usually known by 
 lumbermen and woodsmen generally as "white cedar." The name "white cedar" 
 has in Forest Service publications been used to designate Chamsecyparis thyoides, which 
 is also most widely known as "white cedar." This latter tree, though sometimes found 
 as far north as southern Maine, is of commercial importance chiefly south of Delaware 
 and New Jersey. Thuja occidentalis, common in the northern woods of New England, 
 New York, and the Lake States, occurs as far south as North Carolina and Tennessee, 
 but only in the mountains where the elevation is sufficiently great to permit northern 
 species to thrive. To distinguish these two species without doing violence to ordinary 
 usage, Thuja occidentalis, or "arborvitse," will in the present bulletin receive the name 
 of northern white cedar, and Chamsecyparis thyoides the name of southern white cedar. 
 The western species, Thuja plicata, formerly designated in Forest Service publications 
 as "giant arborvitse," and most commonly known in the West as red cedar, will be 
 called in the present bulletin western red cedar. 
 
 b The following companies contributed to the support of that project: Edison Elec- 
 tric Company, Home Telephone Company, Los Angeles Gas and Electric Company, 
 Los Angeles-Pacific Kailway Company, Pacific Electric Company, Pacific Gas and 
 Electric Company, Pacific Light and Power Company, and San Joaquin Light and 
 Power Company. 
 
 72742°— Bull. 84—11—2 
 
10 
 
 PRESERVATIVE TREATMENT OF POLES. 
 
 RESULTS OF SEASONING TESTS. 
 LOSS OF WEIGHT. 
 
 Table 1 shows in round numbers the weight lost by poles during 
 seasoning until approximately air-dry. After the weights shown in 
 this table have been reached, loss of moisture does not cease, but may 
 continue at a decreasing rate for many months. 
 
 Table 1. — Weight lost during seasoning of poles until approximately air-dry. 
 
 Species. 
 
 Dura- 
 tion of 
 season- 
 ing. 
 
 Green 
 
 weight 
 
 per cubic 
 
 foot. 
 
 "Seasoned 
 
 weight 
 
 per cubic 
 
 foot. 
 
 Green 
 
 weight 
 
 lost. 
 
 Total 
 weight 
 
 lost 
 per pole. 
 
 Nominal size of 
 poles. 
 
 Average 
 volume 
 of poles. 
 
 Diame- 
 ter. 
 
 Length. 
 
 
 Months. 
 4- 8 
 3- 8 
 6-12 
 3- 5 
 
 Pounds. 
 
 56 
 
 a 37 
 
 33 
 
 6 33 
 
 65 
 
 Pounds. 
 47 
 26 
 25 
 25 
 33 
 
 Per cent. 
 16 
 30 
 
 24 
 24 
 49 
 
 Pounds. 
 180 
 228 
 141 
 219 
 835 
 
 Inches. 
 7 
 7 
 7 
 8 
 8 
 
 Feet. 
 30 
 30 
 30 
 40 
 40 
 
 Cubicfeet. 
 20.00 
 
 Southern white cedar 
 
 Northern white cedar 
 
 20.76 
 17.62 
 27.34 
 
 Western yellow pine 
 
 3- 9 
 
 26.10 
 
 a Weight on arriving at Wilmington, N. C, after rafting down the river. 
 
 & Approximate weight on arriving at southern California ports after transportation by boat from Puget 
 Sound. Some of the shipments weighed more. 
 
 The limits of seasoning given in Table 1 are such as would be 
 feasible in commercial practice, and indicate the weight poles must 
 reach in order that the main bulk of the water which may be gotten 
 rid of by air seasoning shall be evaporated. This means a loss ordi- 
 narily of from 16 to 30 per cent of the original weight, amounting to 
 from 141 to 228 pounds per pole in these tests, and for western 
 yellow pine the enormous loss of 49 per cent, or 835 pounds per pole, 
 occurred. Table 2 illustrates the saving in transportation charges 
 possible through pole seasoning. 
 
 Table 2. — Saving in freight charges effected by seasoning of poles. a 
 
 Species. 
 
 Seasoned 
 poles re- 
 quired for 
 minimum 
 carload of 
 
 40,000 
 pounds. 
 
 Total de- 
 crease in 
 weight 
 due to 
 seasoning. 
 
 Saving in freight 
 on carload lots. 
 
 25-cent 
 rate. 
 
 15-cent 
 rate. 
 
 Chestnut 
 
 Southern white cedar 
 Northern white cedar 
 
 Western red cedar 
 
 Western yellow pine . 
 
 Number. 
 
 Pounds. 
 7,700 
 16, 900 
 12, 800 
 12,900 
 38,400 
 
 Dollars. 
 19.25 
 42.25 
 32.00 
 32.25 
 96.00 
 
 Dollars. 
 11.55 
 25.35 
 19.20 
 19.35 
 57.60 
 
 o Based on sizes and weights of poles given in Table 1. 
 
RESULTS OF SEASONING TESTS. 
 
 11 
 
 RATE OF SEASONING. 
 
 The rate at which wood seasons is dependent on many factors, most 
 important of which are climatic and seasonal conditions. Two poles 
 of the same species and in the same locality, but cut at different 
 times of the year, will require different periods of time to lose equal 
 amounts of moisture. Table 3 shows in detail the time required for 
 poles cut at different seasons of the year to reach the degree of dryness 
 given in Table 1 . 
 
 Table 3. — Time required for poles cut at different periods of the year to season to approxi- 
 mately air-dry weight. 
 
 
 Location of test. 
 
 Time required for seasoning. 
 
 Species. 
 
 Spring- 
 cut. 
 
 Summer- 
 cut. 
 
 Autumn- 
 cut. 
 
 Winter- 
 cut. 
 
 
 
 Months. 
 
 5 
 
 3 
 
 ■ 12 
 
 f a& 4 
 
 \ c (3) 
 
 S 
 
 Months. 
 4 • 
 3 
 9 
 a5 
 c(6) 
 3 
 
 Months. 
 8 
 8 
 7 
 i3 
 c(7) 
 9 
 
 Months. 
 7 
 
 
 
 5 
 
 
 
 6 
 
 
 Wilmington, Cal 
 
 a3 
 
 
 
 c(4) 
 6 
 
 
 
 
 a Period of seasoning computed from time poles arrived at Wilmington three to seven months after 
 cutting. 
 b Weight of spring-cut poles at termination of test, 28 pounds per cubic foot, 
 c Period in storage and in transit, during which time little seasoning took place. 
 
 Poles cut during the spring and summer dry rapidly and, except 
 in the case of white cedar in the latitude of northern Michigan, 
 reach an approximately air-dry condition before the following winter. 
 White cedar poles cut during the spring and summer did not become 
 air-dry until the following year, and required more time than poles 
 cut during the autumn and winter to reach an equal degree of dry- 
 ness, the autumn-cut and winter-cut poles becoming dry by the fol- 
 lowing summer. However, during the early part of this experiment 
 the poles lay on skids in the woods, where seasoning was retarded by 
 lack of air circulation and sunshine, and by the swampy character 
 of the soil. In February all poles, consisting of monthly cuts from 
 April to December, inclusive, were removed to the Escanaba yard, 
 where conditions were much more favorable to rapid seasoning. 
 
 The irregularity in the results of the western red cedar tests was 
 caused by the long period the poles were in storage (in water) and in 
 transit, piled solidly on the decks of vessels, little seasoning taking 
 place during this period. 
 
 FACTORS AFFECTING SEASONING. 
 
 The effect of the climatic conditions of different seasons of the year 
 and of various regions in which the tests were made has already been 
 brought out in Table 3, and is more fully shown in the detailed season- 
 
12 
 
 PRESERVATIVE TREATMENT OF POLES. 
 
 ing tables and curves in the Appendix. Besides climatic and seasonal 
 conditions, many other factors affect the rate of drying out of poles, 
 among which are the following: 
 
 (1) Method of piling. — In the tests the poles were spread out in 
 single layers on skids, in which form seasoning is most rapid. Season- 
 ing will be much retarded if the poles are stacked in solid piles, and 
 if that form of pile is used in a warm, moist climate, decay or injury 
 by wood-boring insects is likely to follow should the poles be held for 
 any considerable period. 
 
 (2) Exposure. — Seasoning is hastened by having the poles exposed 
 to a free circulation of air. An open place free from underbrush or 
 other rank growth should be chosen for the skidways. Shade does not 
 
 seem to retard the loss of 
 moisture, provided the circu- 
 lation of air is not impeded. 
 (3) Soaking. — Poles that 
 were soaked from two to four 
 weeks in water dried out very 
 rapidly and in a compara- 
 tively short time reached 
 the same degree of dryness 
 as other poles cut at the 
 same time and not soaked. 
 Thereafter the seasoning of 
 both proceeded at practi- 
 cally the same rate. 
 
 CHECKING. 
 
 Fig. 1.— The shaded areas show progress of decay in an While rapid Seasoning 
 
 untreated pole. Seasoning checks, by increasing the k : f noss ibla to realize 
 
 amount of surface exposed, may hasten decay. maKes ll pObSlDie LO ie<mze 
 
 the benefits of reduced trans- 
 portation costs most quickly, it may be harmful in its effect on the 
 timber itself. Poles seasoned rapidly check more than those seasoned 
 slowly. Timber which seasons slowly and evenly forms numerous 
 small checks, which close again when the wood absorbs moisture 
 and which apparently have no detrimental effect. If, however, the 
 poles season rapidly, wide and deep checks may be formed, which 
 do not again close, and which not only decrease the strength of the 
 timber, but materially hasten decay through the entrance of insects 
 and fungi. Figure 1 shows the detrimental effect of checks that 
 expose a very large surface to decay; they increase the rate of dete- 
 rioration. Splits, windshake, and other defects of this character have 
 a similar influence on the durability of the poles when the defects 
 occur near the ground line. 
 
BRUSH METHOD. 
 
 13 
 
 Some species of wood, notably chestnut, have a tendency to 
 form large checks or splits ; in some cases the split opened a foot wide 
 and extended 9 feet upward on the pole. By the use of S irons at 
 the first indication of a tendency to such checking, serious damage 
 may be avoided. These may be made of strap iron one-eighth inch 
 by 1 inch, bent in the form of a letter S, from 3 to 6 inches long, 
 and driven into the butt of the pole as shown in figure 2. 
 
 SHRINKAGE. 
 
 Hundreds of careful measurements show that the amount of 
 shrinkage which takes place during the seasoning of poles is very 
 slight, though this is contrary to the opinion of pole producers and 
 consumers. The "amount of shrinkage in seasoning from green to air- 
 dry condition averaged from 
 0.3 to 0.5 per cent on the 
 circumference at the ground 
 line (6 feet from the butt), 
 and from 0.6 to almost 1 
 per cent at the top. On 
 the sizes of poles more com- 
 monly used this is equiva- 
 lnet to about 0.1 or 0.2 of 
 an inch in the circumference 
 of the butt and from 0.15 
 to 0.25 of an inch on the top. 
 
 BRUSH METHOD OF TREAT- 
 ING POLES. 
 
 Fig. 2. — An S iron driven into butt of pole to prevent the 
 opening of seasoning checks. 
 
 A very simple method of 
 using a preservative consists 
 in applying it to the surface 
 of the wood with a brush. There " are several patented or pro- 
 prietary preservatives intended for use in this manner. While the 
 experiments show good results from surface applications of anti- 
 septic oils, this form of treatment does not present a complete solution 
 of the question of pole preservation. 
 
 A brush method of treatment has the advantage of very low cost, 
 owing to the small amount of preservative used and to the fact that 
 no special treating apparatus is required. It is especially useful 
 where the number of poles is small, or the region remote, so that the 
 erection of even the most simple form of treating plant would not be 
 justified. In the experiments, a penetration of from one-eighth to 
 one-fourth inch was obtained in seasoned timber. Table 4 shows the 
 amounts of preservative absorbed in a number of tests. The absorp- 
 tion was ascertained by weighing the vessel containing the preserva- 
 
14 
 
 PRESERVATIVE TREATMENT OF POLES. 
 
 tive before and after each treatment, the difference in weight being 
 taken as the amount absorbed by the pole. In all cases the pre- 
 servative was applied hot. a 
 Table 4. — Average absorption of creosote resulting from the brush method of treatment. 
 
 Species. 
 
 Locality. 
 
 Absorption per pole. 
 
 Length 
 of pole. 
 
 Length 
 treated. 
 
 Number 
 of poles 
 averaged. 
 
 1 coat. 
 
 2 coats. 
 
 
 
 Pounds. 
 2.6 
 
 Pounds. 
 4.7 
 4.9 
 4.4 
 6.5 
 
 3.6 
 
 Feet. 
 30 
 30 
 30 
 40 
 
 40 
 
 Feet. 
 a6 
 a6 
 a6 
 68 
 
 67 
 
 92 
 
 
 
 50 
 
 
 
 3.0 
 
 98 
 
 
 Los Angeles and Wilming- 
 ton, Cal. 
 Pollasky, Cal 
 
 75 
 
 Western yellow pine . . . 
 
 2.4 
 
 32 
 
 
 
 a Between 2-foot and 8-foot points on butt. 
 
 b From butt to height indicated. 
 
 Much care should be exercised to fill or coat all season checks with 
 the preservative, for unless this is done the treatment is likely to 
 prove ineffective, because decay will get a foothold in these checks. 
 Only poles which are thoroughly seasoned should be treated and the 
 preservative should not be applied when the surface of the wood is 
 wet, as after a rain, or when very cold. In most cases, better results 
 will be obtained by heating the preservative before applying. Bits 
 of bark adhering to the poles should be carefully removed. While 
 this is necessary in all treatments, it is especially important in brush 
 treatments. Even if the treatment is apparently well done, decay 
 may get a start in the untreated portion underneath the protecting 
 layer of treated wood. 
 
 OPEN-TANK PROCESS OF TREATING POLES. 
 
 The open-tank process of timber treating, the principle of which 
 has been described in another publication, 6 consists in subjecting the 
 timber to successive baths of hot and cold preservatives. In this 
 way atmospheric pressure is used to accomplish to a large extent 
 what is more commonly accomplished by artificial pressure. The 
 open-tank or nonpressure method, like the brush method already 
 described, has the advantage that the preservative may be applied 
 to the butt of the pole only, and this avoids the expense of applying 
 it to the portion above ground, which in many cases is sufficiently 
 durable without treatment. The efficiency of the method as regards 
 the first object of treatment, the impregnation of the wood, is shown 
 in Table. 5. These figures represent typical results obtained in the 
 treatments. 
 
 a As a rough approximation of the quantity of preservative required for pole treat- 
 ments, 1 gallon may be allowed for each 25 square feet of surface to be covered, when 
 two coats are applied. 
 
 & Forest Service Bulletin 78, "Wood Preservation in the United States," by W. F. 
 Sherfesee. 
 
OPEN-TANK PROCESS. 
 
 15 
 
 Table 5. — Average absorption and penetration of creosote obtained in the butt treatment 
 of poles by the open-tank method. 
 
 Species. 
 
 Absorp- 
 tion per 
 pole. 
 
 Penetra- 
 tion. 
 
 Species. 
 
 Absorp- 
 tion per 
 pole. 
 
 Penetra- 
 tion. 
 
 
 Pounds. 
 21.5 
 48.4 
 39.5 
 
 Inches. 
 0.3 
 .5 
 .8 
 
 Western yellow pine 
 
 Pounds. 
 81.4 
 34.0 
 
 Inches. 
 3.1 
 
 
 1.0 
 
 Western red cedar 
 
 
 
 MANNER OF APPLICATION. 
 
 In the open-tank process the impregnation is accomplished by 
 subjecting the timber to a change in temperature, by means of a hot 
 followed by a cooler bath. Any one of three general methods may 
 be followed to accomplish this result: (1) After the timber has been 
 held in the hot preservative for the required length of time, the heat- 
 ing may cease and without other change the whole be allowed to cool; 
 (2) the timber may be transferred from the hot liquid to another tank 
 containing cooler preservative; (3) the preservative may be changed, 
 the hot being drawn off and colder preservative run into the treating 
 tank. The three methods of procedure indicate in a general way the 
 different types of apparatus which may be used in the treatments. 
 
 DURATION OF TREATMENT. 
 
 Many of the experimental treatments were made with long treating 
 periods in order to determine the maximum amount of penetration 
 .or absorption possible, and in some cases further tests showed that 
 very much shorter periods of treatment gave as good or nearly as 
 good results as the long treatments. While it is desirable, in com- 
 mercial practice, to give the treatment in the shortest time possible, 
 the fact should not be overlooked that the open-tank process of 
 treatment is an impregnation process, and differs radically from a 
 mere dipping process, or a coating of the surface with preservatives. 
 It is therefore not advisable to reduce the length of the treatment to 
 such an extent as to risk impairing its efficiency. 
 
 The time necessary to secure any desired penetration or absorption 
 will vary with the species, the moisture condition of the timber, and 
 many other factors, and must be determined by actual test in each 
 case. Some species have a comparatively narrow sapwood, and a 
 heartwood which it is difficult or impossible to penetrate; with such 
 species it is useless to prolong the treatment after the sapwood has 
 been penetrated. Other species, among which are loblolly and 
 western yellow pines, have wide sapwood and treat very easily, and 
 with these it is necessary to regulate the treating period so as to 
 avoid an unnecessarily large absorption of the preservative. 
 
16 PRESERVATIVE TREATMENT OP POLES. 
 
 Except in the case of very dry and porous woods, the absorption 
 takes place mostly during the cooling process. The function of the 
 hot bath is to prepare the wood for treatment. The drier the wood, 
 the shorter the period of the hot bath needed. A long period in the 
 cold bath, allowing the preservative to cool to atmospheric tempera- 
 ture, gives a saturated absorption. Shortening the cold bath and 
 removing the timber while the preservative is still fairly hot gives a 
 relatively deep penetration as compared with the quantity of pre- 
 servative absorbed. This consideration is of especial value in treating 
 porous wood. 
 
 TEMPERATURE OF HOT BATH. 
 
 In most of the experiments the hot bath was given at a tempera- 
 ture slightly above the boiling point of water, that is, from 215° to 
 230° F. There are a number of advantages in using a high tem- 
 perature, and it is especially necessary if timber is not thoroughly 
 air-dry. However, a number of successful treatments were made 
 with temperatures of 200° and less. Further tests should be made 
 to determine the lowest efficient hot-bath temperature for the treat- 
 ment of seasoned poles. In order that volatilization of creosote may 
 be reduced to a minimum, it is desirable that the hot bath be given 
 at as low a temperature as possible without impairing the efficiency 
 of the treatment. 
 
 INFLUENCE OF RATE OF GROWTH. 
 
 Among trees of the same species, those having wide annual rings 
 commonly have wider sapwood than those whose growth has been 
 less rapid, and since in many species it is only the sapwood that is 
 penetrated, it follows that the pole of rapid growth will absorb more 
 preservative than the one of slow growth. Chestnut poles showing 
 a maximum growth of 2 rings to the inch absorbed the preservative 
 to a depth of 0.75 of an inch, while others having 15 annual rings 
 to the inch received a penetration of only 0.2 of an inch. The pene- 
 tration in the case of northern white cedar poles averaged 0.6 of an 
 inch for poles with less than 20 rings to the inch and 0.4 of an inch 
 for those having more than 40 rings to the inch. 
 
 It is probable that the variation in wood structure due to difference 
 in rate of growth, aside from the relative amounts of heartwood and 
 sapwood, affects the absorption and penetration of preservative, but 
 there is no conclusive evidence on this point. 
 
 INFLUENCE OF MOISTURE. 
 
 In general, the drier the wood the more readily it may be treated. 
 Poles thoroughly air-seasoned require less time for treatment than 
 those only partially seasoned. The treatment of green timber is 
 
Bui. 84, Forest Service, U. S. Dept. of Agriculture. 
 
 Plate I. 
 
 Fig. 1.— Treating White Cedar by Brush Method. 
 
 Fig. 2.— Treating Chestnut Poles by Open-Tank Method. 
 
ADVANTAGES AND LIMITATIONS. 17 
 
 unsatisfactory because of the small absorption and irregular penetra- 
 tion of the preservative. Another important reason why unseasoned 
 poles should not be treated is that such poles are likely to check in 
 drying, and thus expose untreated wood to decay. 
 
 INFLUENCE OF SEASON OF CUTTING. 
 
 In the experiments with western yellow pine, poles cut in different 
 seasons of the year differed greatly in the ease with which they 
 absorbed the preservative, the summer-cut poles absorbing less than 
 those cut at any other season. This difference in absorptive qualities 
 may have been due to rate of seasoning and rate and conditions of 
 growth, rather than to inherent differences in the wood due to the 
 time of cutting. It is known that absorption may be retarded by 
 "case hardening" that may result from too rapid drying. Tests on 
 chestnut show that poles having the same moisture content, although 
 they were cut at different periods of the year, absorb the same quan- 
 tities of preservative. 
 
 INFLUENCE OF SOAKING IN WATER. 
 
 Chestnut poles which had been soaked in water two weeks and 
 then seasoned did not absorb any more creosote than poles that had 
 not been soaked. . Soaking in water is rarely justified as a means of 
 making wood more permeable to preservatives. 
 
 ADVANTAGES AND LIMITATIONS OF THE OPEN-TANK PROCESS. 
 
 The tests made by the Forest Service indicate that the sap^vood 
 of a great variety of species, including nearly all of our common 
 native woods, when seasoned can be successfully impregnated by the 
 open-tank process. The heartwood of many species offers consider- 
 able resistance to impregnation and can not be so well treated without 
 pressure. However, with the exception of a few species having an 
 unusually narrow sapwood, it is believed that the thorough treat- 
 ment of the sapwood portion of round timber will afford good pro- 
 tection to the entire stick. Since poles are almost always used in 
 the round, the open-tank process is especially well adapted to the 
 treatment of this class of timber. The apparatus required is com- 
 paratively simple and inexpensive, especially where but few poles 
 are to be handled, and if desired can be made portable. 
 
 The open-tank process is not adapted to the treatment of woods 
 which are difficult to impregnate, nor to unseasoned or partially 
 seasoned wood, and as regards economy of operation has not justified 
 itself in plants designed for the treatment of the entire pole. The 
 large amount of oil lost by volatilization from open tanks and the 
 difficulty of accurately gaging and regulating the amount absorbed 
 are other disadvantages. 
 
 72742°— Bull. 84—11 3 
 
18 PKESERVATIVE TREATMENT OP POLES. 
 
 RESULTS OF TREATMENTS, BY SPECIES. 
 CHESTNUT. 
 
 Chestnut is widely distributed throughout the entire Appalachian 
 mountain region and is extensively cut for poles, ranking next to the 
 cedars in the quantity used. The reported number of chestnut poles 
 purchased in 1909 was 608,000.° Chestnut is durable, and the esti- 
 mated average length of life of an untreated pole is from 10 to 12 
 years. The sapwood is very narrow, usually from about one-eighth 
 to three-eighths of an inch wide. The heartwood of chestnut, like 
 that of many other species, is difficult to impregnate with preserva- 
 tives, and the penetration secured in the treatment is comparatively 
 small. This fact, however, does not constitute a valid reason for not 
 giving the wood such treatment as is possible. While the absorp- 
 tion of the small amount of preservative and the small penetration 
 can not be expected to prolong the life of the timber to the same 
 extent as would a greater absorption and depth of penetration, the 
 increased life secured will undoubtedly more than pay for the cost of 
 the treatment. 
 
 A large number of tests were made in the seasoning of chestnut 
 poles, and the rate of seasoning was determined for a number of 
 localities. Poles cut near Parkton, Md., and having an average green 
 weight of 56 pounds per cubic foot, reached a weight of 47 pounds in 
 from 4 to 8 months, depending upon the time of cutting. The fall 
 and winter cut poles of the same lot, at the end of 12 and 9 months, 
 respectively, had reached a weight of 45 pounds, and winter-cut 
 poles at Thorndale, Pa., weighing 53 pounds per cubic foot to begin 
 with, dropped to 42 pounds in 11 months, remaining practically sta- 
 tionary in weight at that point. 
 
 Brush Treatments. — Brush treatments were made in each of the 
 tests with chestnut poles. As an example of the results obtained 
 and because these poles will be referred to again in this bulletin, 6 the 
 treatments made at Pisgah, N. C, are given in detail in Table 7. The 
 poles were treated for a distance of 6 feet, beginning 2 feet from the 
 butt. 
 
 a Bureau of the Census: " Poles Purchased, 1909." 
 
 b Appendix, "Report on Inspection of Experimental Poles. ■ ' 
 
EESULTS OF TREATMENTS. 
 
 19 
 
 Table 7. — Amount of preservative absorbed in the brush treatment of chestnut poles at 
 
 Pisgah, N. C. 
 
 Preservative sold as — 
 
 Number 
 of coats. 
 
 Absorption per pole. 
 
 Average. 
 
 Maximum. 
 
 Minimum. 
 
 
 2 
 1 
 2 
 1 
 3 
 2 
 3 
 1 
 2 
 2 
 1 
 
 Pounds. 
 4.1 
 3.7 
 4.2 
 3.2 
 6.7 
 7.0 
 6.5 
 5.1 
 5.4 
 6.4 
 7.0 
 
 Pounds. 
 5.1 
 4.6 
 5.5 
 3.9 
 9.0 
 10.6 
 8.3 
 5.5 
 7.0 
 8.4 
 
 Pounds. 
 2.9 
 
 
 2.4 
 
 
 3.1 
 
 
 2.5 
 
 
 4.9 
 
 
 4.3 
 
 
 3.8 
 
 
 4.6 
 
 
 3.8 
 
 
 4.5 
 
 Tar 
 
 
 
 
 
 The thin sapwood of chestnut has a tendency to scale off after the 
 pole has been exposed for some time to the weather. An inspection 
 of brush-treated chestnut poles shows that in certain cases the failure 
 of the treatment was due to this cause. Possibly better results would 
 be secured from brush treatments if the sapwood were shaved off for 
 a few feet above and below the ground line, so that the preservative 
 would be applied to the more firm heartwood. 
 
 Tank Treatments. — Table 8 shows the results of the treatment of 
 chestnut poles at Parkton, Md., with creosote, by the open-tank proc- 
 ess. Treatments at Dover, N. J., and Thorndale, Pa., gave somewhat 
 similar results. 
 
 Table 8. — Absorption and penetration of creosote in the open-tank treatment of chestnut 
 
 poles, Parkton, Md. 
 
 Treatment. 
 
 Number 
 
 of rings 
 
 in outer 
 
 inch. 
 
 Average 
 penetra- 
 tion. 
 
 Average 
 absorp- 
 tion. 
 
 Basis 
 poles. 
 
 Hot oil. 
 
 Cooling 
 oil. 
 
 Cold 
 
 oil. 
 
 Tempera- 
 ture of 
 hot oil. 
 
 Hours. 
 10 
 8 
 6 
 4 
 6 
 4 
 
 Hours. 
 14 
 14 
 14 
 14 
 
 Hours, 
 
 "F. 
 228 
 223 
 225 
 225 
 229 
 231 
 
 10 
 10 
 8 
 8 
 9 
 7 
 
 Inch. 
 0.30 
 .29 
 .34 
 .33 
 .34 
 .38 
 
 Pounds. 
 20.7 
 21.3 
 23.6 
 20.9 
 21.3 
 20.6 
 
 Number. 
 16 
 8 
 24 
 24 
 24 
 16 
 
 
 
 
 2 
 2 
 
 
 
 It appears from this table that four hours in hot oil gives nearly 
 as good a treatment as a longer period and that by changing the 
 poles to the tank containing cold oil as good results are obtained 
 in two hours as by leaving the poles in cooling oil overnight. The 
 penetration in all cases was small, averaging from 0.3 to 0.4 of an 
 inch. No tests were made with shorter periods of treatment, but 
 it is probable that for practical purposes an efficient treatment can 
 be given well-seasoned chestnut poles in a somewhat shorter period 
 
20 
 
 PEESEEVATIVE TBEATMENT OF POLES. 
 
 than six hours. Poles with wide annual rings and wide sap wood 
 absorbed more oil and showed a deeper penetration than those having 
 a slower growth and narrower sapwood.. 
 
 SOTJTHEEN WHITE CEDAR. 
 
 The white cedar of the South, or "juniper," as it commonly called 
 by telephone men, is used locally to a considerable extent for poles. 
 The woods known under the general name of "cedar" comprise a 
 number of distinct species and differ in their durability, the white 
 cedar of the southern swamps being somewhat less durable than 
 the cedar of the Lake States. 
 
 Pole-using companies reported 44,000 a southern white cedar poles 
 purchased in 1909. The average life is assumed to be from ten to 
 thirteen years, but in unfavorable situations a large proportion of the 
 poles fail in a shorter period. The sapwood, which is usually from 
 one-half to 1 inch wide, decays very quickly. The poles used in the 
 southern white cedar experiments were cut in the swamps of North 
 Carolina and rafted about 90 miles down the Cape Fear River to 
 Wilmington, where they were placed on skidways and seasoned until 
 they reached a weight of from 25 to 26 pounds per cubic foot. South- 
 ern white cedar received brush treatments alone, and a number of 
 different preservatives were used. As in the case of chestnut, a 
 6-foot space was treated, between the 2-foot and 8-foot points at 
 the base of the pole. The results are summarized in Table 9. 
 
 Table 9. — Amount of preservative absorbed in the brush treatment of southern white 
 cedar a at Wilmington, N. C. 
 
 Preservative sold as — 
 
 Number 
 of coats. 
 
 Absorption per pole. 
 
 Average. Maximum. Minimum 
 
 Avenarius Carbolineum 
 
 S. P. F. Carbolineum 
 
 Do 
 
 Spirittine 
 
 Creosote 
 
 Do 
 
 Imperial Wood Preservative 
 
 Creolin ■ 
 
 Tar 
 
 Pounds. 
 3.6 
 3.7 
 1.6 
 
 4.7 
 4.9 
 7.1 
 4.4 
 6.0 
 7.0 
 
 Pounds. 
 4.7 
 5.3 
 1.6 
 5.5 
 6.4 
 8.0 
 5.3 
 7.4 
 
 Pounds. 
 2.6 
 2.8 
 1.6 
 4.1 
 3.3 
 5.6 
 3.4 
 4.5 
 
 a These poles were included in the experimental line set near Savannah, Ga., a report on the inspection 
 of which is given in the Appendix. 
 
 NORTHERN WHITE CEDAR. 
 
 This species is very commonly used for poles throughout the cen- 
 tral and eastern portion of the United States, and, together with 
 smaller quantities of chestnut and oak, is the main source of supply 
 
 a Bureau of the Census: " Poles Purchased, 1909." 
 
KESULTS OF TREATMENTS. 
 
 21 
 
 for these regions. Of the three and three-fourths million poles pur- 
 chased in 1909 by telephone, telegraph, electric power, and steam 
 railway companies, two and four-tenths millions, or about two-thirds, 
 were cedar. a While the statistics do not separate the northern 
 white cedar from other timbers known commercially as cedar, it is 
 certain that by far the greater number are of this species, the principal 
 source of supply of which is in the States bordering the Great Lakes. 
 It makes a very desirable pole, since it lasts from twelve to fifteen 
 years untreated. Northern white cedar is a high-priced pole timber, 
 however, and it will undoubtedly pay to apply preservative treatment 
 to increase the durability of the poles and thus decrease the annual 
 service charge. The treating experiments included brush treatments 
 with creosote and with carbolineum, and open-tank treatment with 
 creosote. The poles were seasoned until approximately air-dry and 
 weighed 22^ pounds per cubic foot at the time of treatment. 
 
 Brush Treatments. — The preservative was applied to the butts 
 between the 2-foot and 8-foot points. 
 
 Table 10. 
 
 -Amount of 'preservative absorbed in the brush treatment of northern white 
 Cedar poles, Escanaba, Mich. 
 
 Preservative sold as — 
 
 Number 
 of poles 
 averaged. 
 
 Absorption. 
 
 First 
 coat. 
 
 Second 
 coat. 
 
 Total. 
 
 Carbolineum 
 
 Creosote 
 
 98 
 98 
 
 Pounds. 
 
 . 2.4 
 
 3.0 
 
 Pounds. 
 1.5 
 1.4 
 
 Pounds. 
 3.9 
 4.4 
 
 The penetration of the preservative in these treatments did not 
 average more than one-sixteenth of an inch. The work was done 
 during the winter, and, although the preservative was heated to 
 between 200° and 220° F., the low temperature of the timber and 
 atmosphere caused it to thicken on the surface of the wood. Under 
 more favorable conditions the penetration should be deeper. 
 
 Tank Treatments. — Creosote tank treatments were made by 
 heating the poles in the oil and maintaining the temperature at 
 approximately 220° F. for from three to twelve hours and allowing 
 them to cool in the oil overnight. A summary of the results is 
 given in Table 1 1 . 
 
 a Bureau of the Census: " Poles Purchased, 1909." 
 
22 
 
 PEESERVATIVE TREATMENT OF POLES. 
 
 Table 11. — Amount of preservative absorbed in the open-tank treatment of northern 
 white cedar poles, Escanaba, Mich. 
 
 Number 
 of poles 
 averaged. 
 
 Duration of treatment. 
 
 Absorp- 
 tion per 
 pole.. 
 
 Hot oil. 
 
 Cooling oil. 
 
 34 
 75 
 43 
 
 Hours. 
 
 3 to 5 
 
 6 
 
 7 to 12 
 
 Hours. 
 
 Overnight 
 
 do 
 
 do 
 
 Pounds. 
 42 
 49 
 50 
 
 
 There was considerable irregularity in the results on different 
 poles in the same treatment, but the general tendency is well shown 
 by grouping the treatments and thus averaging a greater number of 
 poles, as in Table 11. Little practical advantage seems to be gained 
 by prolonging the hot bath above three or four hours, although the 
 absorption averages somewhat higher. The average penetration 
 obtained in the treatment was approximately 0.5 inch, varying 
 from 0.2 to 1 inch. The sapwood of the poles varied from 0.5 to 
 1.0 inch in thickness. 
 
 A very large proportion of northern white cedar poles have un- 
 sound butts, 60 per cent of the experimental poles having defects 
 more than 1 inch in diameter. In these tests, poles with sound 
 butts absorbed, on an average, 11.1 pounds less than those with 
 unsound butts. 
 
 The treatments on northern white cedar were made with one 
 tank only, which prevented a change from hot to cold oil. Tests 
 with other species indicate that by a change of baths the results 
 obtained by cooling overnight could have been accomplished in a 
 few hours. 
 
 WESTERN RED CEDAR. 
 
 The light and durable western red cedar is much used for poles 
 on the Pacific coast and throughout the Northwest. Also, it com- 
 petes to a certain extent with northern white cedar in the East, its 
 form and size making it especially desirable for the larger classes 
 of poles. The principal points of production are northern Idaho 
 and western Washington. The relative durability of western red 
 and northern white cedar under similar conditions is not known, 
 and the testimony by pole users on this point is somewhat contra- 
 dictory. Experiments with western red cedar poles from the Puget 
 Sound region were made at Wilmington and Los Angeles, Cal. 
 
 Brush Treatments. — Brush treatments of creosote and car- 
 bolineum were made, the preservative being applied to the butts 
 of 40-foot poles to a height of 8 feet. The absorptions are shown 
 in Table 12. 
 
RESULTS OF TREATMENTS. 
 
 23 
 
 Table 12. 
 
 -Amount of preservative absorbed in the brush treatments of western red cedar 
 (40-foot poles). 
 
 CREOSOTE. 
 
 Number 
 
 poles 
 averaged. 
 
 Season cut. 
 
 Summer . 
 
 Fall 
 
 Winter. . 
 Spring... 
 
 Weight 
 per cubic 
 
 Absorption per 
 
 pole. 
 
 
 
 
 foot of 
 poles, a 
 
 First 
 coat. 
 
 Second 
 coat. 
 
 Total. 
 
 Pounds. 
 
 Pounds. 
 
 Pounds. 
 
 Pounds. 
 
 22 
 
 00 
 
 00 
 
 12.4 
 
 23 
 
 00 
 
 0) 
 
 8.7 
 
 24 
 
 2.3 
 
 1.5 
 
 3.8 
 
 28 
 
 2.0 
 
 1.5 
 
 3.5 
 
 SOLD AS CARBOLINEUM. 
 
 12 
 10 
 10 
 29 
 
 
 22 
 23 
 24 
 28 
 
 0) 
 
 0) 
 2.6 
 2.7 
 
 0) 
 
 0) 
 2.1 
 2.0 
 
 10.3 
 5.6 
 4.7 
 4.6 
 
 Fall 
 
 
 
 
 a Indicates stage of seasoning. 
 
 b First and second coats not recorded separately. 
 
 The absorption is relatively small when the preservative is applied 
 .to comparatively unseasoned poles that weigh as much as 28 pounds 
 per cubic foot and forms scarcely more than a coating on the surface. 
 The increase in absorption is very slight until the weight falls below 
 24 pounds, when it becomes rapid. At a weight of 22 pounds per 
 cubic foot the absorption is two or three times as great as when the 
 poles are in only a slightly greener stage. The penetration on the 
 best seasoned poles averaged about one-eighth of an inch. Where 
 the surface of the pole had become roughened by weathering, the 
 penetration reached a maximum of one-half inch. 
 
 Tank Treatment with Creosote. — In order to determine the 
 maximum amount of creosote that could be injected, a number of 
 treatments were made, keeping the poles in hot oil for periods ranging 
 from one to six hours, at a temperature of between 220° and 230° F., 
 and allowing them to cool overnight. For these treatments, summer 
 and autumn cut poles were used, seasoned until they weighed, respec- 
 tively, from 22 to 23^ and from 24 to 25 pounds per cubic foot. The 
 absorption and penetration obtained are shown in Table 13. 
 
24 
 
 PRESERVATIVE TREATMENT OP POLES. 
 
 Table 13. — Absorption and penetration of creosote in the open-tank treatment of western 
 red cedar poles' at Wilmington, Cal. 
 
 Dura- 
 tion of 
 hot 
 bath. 
 
 Summer cut. 
 
 Autumn-cut. 
 
 35-foot poles, o- 
 
 40-foot poles, a 
 
 40-foot poles, a 
 
 Poles 
 aver- 
 aged. 
 
 Absorp- 
 tion. 
 
 Pene- 
 tration. 
 
 Poles 
 aver- 
 aged. 
 
 Absorp- 
 tion. 
 
 Pene- 
 tration. 
 
 Poles 
 aver- 
 aged. 
 
 Absorp- 
 tion. 
 
 Pene- 
 tration. 
 
 Hours. 
 1 
 2 
 3 
 4 
 5 
 6 
 
 Number. 
 24 
 
 Pounds. 
 36.5 
 
 Inches. 
 0.68 
 
 Number. 
 
 Pounds. 
 
 Inches. 
 
 Number. 
 
 Pounds. 
 
 Inches. 
 
 23 
 
 45.5 
 
 0.90 
 
 12 
 
 33.0 
 
 0.60 
 
 33 
 13 
 
 34.0 
 43.0 
 
 .77 
 .90 
 
 12 
 
 24 
 
 46.0 
 46.5 
 
 .98 
 1.00 
 
 23 
 24 
 
 48.0 
 43.0 
 
 .65 
 .62 
 
 14 
 
 31.0 
 
 .SO 
 
 
 
 
 
 
 ^35-foot poles were treated to a height of approximately 6.5 feet and 40-foot poles approximately 7 feet. 
 The average volume of the butt of a 40-foot pole is 6.5 cubic feet. 
 
 These treatments represent complete or practically complete pene-. 
 tration of the sapwood. Little or no penetration was obtained in the 
 heartwood. The shorter periods of heating (with the long cooling 
 periods) give nearly as good results as longer periods of heating. The 
 effect of duration of treatment is more fully brought out in Table 14. 
 
 Table 14. — Effect of duration of treatment on the absorption and penetration of creosote in 
 the treatment of toestern red cedar poles. a 
 
 Duration 
 of hot 
 bath. 
 
 One hour cold bath. 
 
 Two hours cold bath. 
 
 Fifteen hours cooling. 
 
 Poles 
 aver- 
 aged. 
 
 Absorp- 
 tion per 
 pole. 
 
 Pene- 
 tration. 
 
 Poles 
 aver- 
 aged. 
 
 Absorp- 
 tion per 
 pole. 
 
 Pene- 
 tration. 
 
 Poles 
 aver- 
 aged. 
 
 Absorp- 
 tion per 
 pole. 
 
 Pene- 
 tration. 
 
 Hours. 
 1 
 2 
 3 
 4 
 
 Number. 
 
 Pounds. 
 
 Inches. 
 
 Number. 
 
 Pounds. 
 
 Inches. 
 
 Number. 
 
 10 
 
 6 
 
 4 
 
 5 
 
 Pounds. 
 27.0 
 37.7 
 41.0 
 32.5 
 
 Inches. 
 
 0.58 
 
 .65 
 
 .60 
 
 .47 
 
 7 
 5 
 6 
 
 25.6 
 18.5 
 26.0 
 
 0.48 
 .38 
 
 .46 
 
 6 
 
 19.5 
 
 0.35 
 
 6 
 
 23.8 
 
 .01 
 
 a Autumn-cut 40-foot poles seasoned to 23 pounds per cubic foot. 
 
 It is seen from Table 14 that good treatments may be given in 
 three hours ( two hours hot and one hour cold) , but that the results do 
 not average quite as high as in some of the longer treatments. The 
 six-hour treatments (four hours in hot oil and two in cold) seem to 
 give as good penetration as cooling overnight, and to accomplish this 
 with the absorption of a smaller quantity of oil. Because of the irreg- 
 ularities in these results, the best period of treatment is not definitely 
 determined, but it is believed that for very dry poles the short treat- 
 ment will prove satisfactory, while if the timber is not so well seasoned 
 it will be necessary to prolong the treatment. The effect of the degree 
 of seasoning is illustrated in Table 15. 
 
Plate 
 
Bui. 84, Forest Service, U. S. Dept. of Agriculture. 
 
 Plate III 
 
 Fig. 1 .—Cross-Section of Western Red Cedar Pole Butt, 10 
 Inches in Diameter, Showing Penetration of Creosote; Open- 
 Tank Treatment. 
 
 Fig. 2.— Cross-Section of Western Yellow Pine Pole Butt, 
 14 Inches in Diameter, Showing Penetration of Creo- 
 sote; Open-Tank Treatment. 
 
RESULTS OF TREATMENTS. 
 
 25 
 
 Table 15. — Effect of degree of seasoning on absorption and penetration of creosote in the 
 treatment of western red cedar poles. a 
 
 Time of cutting. 
 
 Weight per 
 cubic foot 
 
 before 
 treating. 
 
 Absorption 
 per pole. 
 
 Penetra- 
 tion. 
 
 Poles 
 averaged. 
 
 
 Pounds. 
 22-23J 
 24-25 
 28 
 
 Pounds. 
 45.2 
 43.0 
 28.4 
 
 Inches. 
 0.93 
 .63 
 .37 
 
 Number. 
 71 
 
 Fall 
 
 59 
 
 
 26 
 
 
 
 a Treatment consists of immersion from two to seven hours in hot oil and cooling overnight. 
 
 While the poles used in obtaining these averages did not all have the 
 same period of treatment, the same range of treatments applies to 
 each of the several groups. Other treatments were made, the results 
 of which do not exactly coincide with those here given, but notwith- 
 standing the great variability in individual poles the table serves to 
 illustrate the relative absorptive power of the poles in different stages 
 of seasoning. 
 
 Tank Treatment with Zinc Chlorid. — A number of treatments 
 were made with zinc chlorid solution, mostly in long runs, keeping the 
 bath at 212° F. for from four to seven hours and allowing the poles to 
 cool in it overnight. The absorptions obtained are summarized in 
 Table 16. 
 
 Table 16. — Absorption of zinc chlorid solution in the treatment of western red cedar poles. 
 
 Time of cutting. 
 
 Weight per 
 cubic foot 
 
 before 
 treating. 
 
 Poles 
 averaged. 
 
 Number. 
 8 
 
 20 
 90 
 
 Duration of treatment. 
 
 Average 
 absorp- 
 
 Hot bath. 
 
 Cooling. 
 
 tion per 
 pole. 
 
 
 Pounds. 
 22J 
 24" 
 28 
 
 Hours. 
 
 5 
 
 6 
 
 4-7 
 
 Hours. 
 
 Overnight 
 
 do 
 
 do 
 
 Pounds. 
 61.5 
 
 
 52 
 
 
 45 
 
 
 
 
 Table 16 illustrates the variation in amount of absorption of pre- 
 servative solution obtained with poles in several stages of seasoning. 
 A number of runs giving irregular results are not included in this 
 table. Fall-cut poles seasoned to 23 pounds per cubic foot absorbed 
 on an average only 30 pounds of solution per pole, and one lot of 
 winter-cut poles seasoned to 25 pounds per cubic foot absorbed only 
 21 pounds per pole, the poles all being given treatment of practically 
 the same duration. As a rule, however, the absorption of zinc chlorid 
 solution was slightly higher than that of creosote for the same period 
 of treatment and increases, other things being equal, as the moisture 
 content of the wood decreases. 
 
 In a few treatments, the poles, instead of being left overnight in the 
 cooling solution, were removed from the hot bath after from two to six 
 hours and transferred to cold solution, in which they were left stand- 
 72742°— Bull 84—11 4 
 
26 PRESERVATIVE TREATMENT OF POLES. 
 
 ing from one-half to two hours. This method resulted in an average 
 absorption of 28 pounds solution per pole. In the treatment of west- 
 ern red cedar poles with zinc chlorid the aim should be to secure a 
 complete saturation of the sapwood. The strength of the solution 
 need not exceed 5 per cent. 
 
 Other Treatments. — A few tests were made with crude petroleum, 
 but very little penetration was obtained. Poles seasoned until they 
 weigh 25 pounds or less per cubic foot may be given a combination 
 creosote and zinc chlorid treatment by heating them in a creosote 
 bath and then changing and allowing them to cool in the zinc chlorid, 
 but poles first treated with zinc chlorid solution will take very little 
 creosote if dipped into the oil while they are in a saturated condition. 
 However, such poles may be allowed to dry out and may then be 
 dipped into a tank of heavy oil, or receive a brush treatment. A treat- 
 ment of this character ought to prevent to a large extent the leaching 
 out of the zinc chlorid. 
 
 WESTERN YELLOW PINE. 
 
 Western yellow pine is used for poles to a limited extent in certain 
 parts of the Southwest, where the high cost of more durable pole tim- 
 bers makes it necessary to find a cheaper substitute. The life of this 
 timber, untreated, is very short. In the upper part of the San Joaquin 
 Valley of California, where a study of this species was made, untreated 
 pine poles last only two or three years; but since the wood when not 
 exposed to the soil is fairly durable, it is believed that a butt treatment 
 with a good wood preservative will result in a pole that will give good 
 service. A butt-treated pine pole costs considerably less than an 
 untreated cedar pole in this locality. Fortunately, western yellow 
 pine is a timber which takes treatment very readily, and no difficulty 
 is encountered in securing any desired absorption if the poles are 
 seasoned. 
 
 Seasoning tests were made at Northfork, Madera County, Cal., 
 where about 650 poles were cut, the cutting periods being distributed 
 throughout the year. The green weight of the poles averaged slightly 
 above 65 pounds per cubic foot, 40-foot poles averaging about 1,700 
 pounds. The treatments were made when the poles had lost from 50 
 to 55 per cent of their original weight, and weighed from 30 to 32 
 pounds per cubic foot. From three to ten months were required to 
 reach this degree of dryness. 
 
 Brush Treatments. — Brush treatments were made with carbo- 
 lineum and creosote, the preservative being applied to a height of 8 
 feet on the pole butts. 
 
RESULTS OF TREATMENTS. 
 
 27 
 
 Table 17. — Amount of preservative absolved in the brush treatment of western yellow 
 
 pine poles. 
 
 
 Poles av- 
 eraged. 
 
 Absorption. 
 
 Preservative sold as — 
 
 First 
 coat. 
 
 Second 
 coat. 
 
 Total 
 
 
 Number. 
 27 
 32 
 
 Pounds. 
 3.0 
 2.4 
 
 Pounds. 
 1.8 
 1.2 
 
 Pounds. 
 4.8 
 
 
 3.6 
 
 
 
 The penetration for creosote ranged from one-sixteenth to one- 
 fourth of an inch, averaging about one-eighth of an inch, and for car- 
 bolineum from one-sixteenth to one-half of an inch, with an average 
 of about three-sixteenths of an inch. 
 
 Tank Treatments with Creosote. — Tank treatments were made 
 both by allowing the poles to cool in the hot-bath tank, and by trans- 
 ferring them to a tank containing cooler oil. The results of a number 
 of treatments by the former method are given in Table 18. 
 
 Table 18. — Absorption and penetration of creosote in the open-tank treatment of 
 western yellow pine poles. 
 
 Poles 
 averaged. 
 
 Duration 
 of hot 
 bath. 
 
 Maxi- 
 mum 
 temper- 
 ature. 
 
 Duration 
 of cool- 
 ing 
 bath. 
 
 Final 
 heating 
 temper- 
 ature. 
 
 Absorp- 
 tion per 
 pole, a 
 
 Pene- 
 tration. 
 
 Number. 
 42 
 56 
 
 Hours. 
 3 
 3 
 
 °F. 
 170-200 
 170-200 
 
 Hours. 
 14 
 14 
 
 "F. 
 
 200 
 
 Pounds. 
 81.4 
 55.5 
 
 Inches. 
 3.1 
 3.3 
 
 a The average volume of the portion treated was 6.25 cubic feet. 
 
 As shown in Table 18, three hours in hot oil and cooling overnight 
 gave an average penetration of 3.1 inches, with an absorption of 81 
 pounds of creosote per pole, or 13 pounds per cubic foot. Reheating 
 after the same period of treatment resulted in approximately the 
 same penetration, with a final absorption, however, of only about 
 56 pounds per pole, or 9 pounds per cubic foot. A part of this 
 difference may be accounted for by volatilization, which, while the» 
 wood and oil are hot, is doubtless rapid enough to have some effect 
 during the interval between the removal of the pole from the tank 
 and the weighing. Nevertheless, there is a substantial saving in 
 creosote by removing the poles from the oil while hot (after cooling 
 10° or 20° from the maximum temperature), or by reheating the oil 
 as in the case described. By this method the wood cells and cavities 
 do not become supersaturated with .oil to the same extent as when 
 the treatment is completed with the creosote at a low temperature. 
 
 Very good results were also obtained by shorter treatment, both 
 by allowing the poles to stand in the tank at the completion of the hot 
 
28 PRESERVATIVE TREATMENT OP POLES. 
 
 bath until the temperature had fallen 20° or 30° F. or by transferring 
 them to a tank containing cooler oil for a short period. 
 
 Absorption is much influenced by rainfall and atmospheric condi- 
 tions. During hot, dry weather heating the poles for an hour in the 
 hot oil and dipping them a few minutes in the cold tank resulted in 
 an absorption of 6 pounds of creosote per cubic foot and a penetration 
 of 2 or 3 inches. At this time some of the poles absorbed a large 
 amount during the hot bath, without the cooling process. In the 
 cooler, rainier period before the dry weather set in, the hot bath 
 resulted in an absorption of only 6 or 8 pounds of oil per pole. 
 
 Tank Treatments with Zinc Chlorid. — Absorptions of zinc 
 chlorid solutions average somewhat higher than creosote for the 
 same periods of treatment. An average of about 18 pounds of 
 solution per cubic foot a was obtained by giving the poles a hot bath 
 of two or three hours, followed by cooling overnight. Standing the 
 poles in cold solution for fifteen hours resulted in an absorption of 
 nearly 10 pounds per cubic foot, and an absorption of 12 pounds to 
 the cubic foot was obtained by a three-hour treatment, consisting of 
 a hot bath followed by a change to cold solution. One-half a pound 
 of dry zinc chlorid per cubic foot of timber is the amount commonly 
 used in commercial practice for the treatment of crossties; that 
 amount is approximated by using a 3 per cent solution for an absorp- 
 tion of 16 to 18 pounds or a 4 per cent solution if the absorption is 12 
 or 14 pounds to the cubic foot. Solutions varying in strength from 3 to 
 10 per cent were used in the tests in order that the effect of various 
 quantities of zinc chlorid on the durability of the wood may be 
 determined by the durability of the poles in service in an experi- 
 mental line. 
 
 Tank Treatment with Creosote and Zinc Chlorid. — A treat- 
 ment of both creosote and zinc chlorid may be given by using the 
 former for the hot bath and the latter for the cold bath. The solution 
 penetrates readily through the creosoted wood, the result being a 
 pole with creosote in the exterior zone and zinc chlorid in the interior 
 portion. It is, however, difficult to control the relative amounts of 
 ' creosote and solution absorbed, and if the poles are quite dry more 
 than the desired amount of the former may be taken up during the 
 heating process. 
 
 Tank Treatments with Crude Petroleum. — Treatments with 
 a heavy grade of crude petroleum were made, but impregnation is 
 more difficult than with creosote. Two or three hours in hot oil, 
 followed by cooling overnight, resulted in an average absorption of 
 56 pounds per pole and a penetration of 2 inches. There is little 
 definite knowledge, however, of the value of crude petroleum as a 
 wood preservative. 
 
 ° The average volume of the portion treated was 6.25 cubic feet. 
 
Bui. 84, Forest Service, U. S. Dept. of Agriculture. 
 
 Plate IV. 
 
 Cross-Section of a Small Loblolly Pine Pole, Showing Penetration of Cre 
 
RESULTS OP TREATMENTS. 29 
 
 LODGEPOLE PINE. 
 
 Lodgepole pine grows at high altitudes in the Kocky Mountains, 
 and is extensively cut for lumber, ties, and mine timbers, and to a 
 limited extent for poles. Like the yellow pine, it decays quickly in 
 contact with the soil, but is durable when not so exposed. The tree 
 grows tall and straight, with very little taper, and makes a well- 
 shaped pole. In certain parts of the West, where there are large 
 bodies of fire-killed lodgepole that remain standing for many years, 
 sound and throughly seasoned, conditions for effective treatment 
 are excellent. If given a butt treatment, this dead timber makes a 
 durable pole, and in many localities the cost of the pine pole plus the 
 cost of the treatment is less than that of the Idaho cedar untreated. 
 The sap wood of lodgepole pine, which on pole-size timber may be an 
 inch or an inch and a quarter thick, is easily impregnated. In the 
 treatments made by the Forest Service four hours were required to 
 accomplish this result, hot and cold baths of about equal duration 
 being used. About 35 pounds of oil were absorbed in the butt treat- 
 ment of 30-foot poles. 
 
 LOBLOLLY PINE. 
 
 The pines are much used for poles in the South, but, with the excep- 
 tion of the resinous heart of long-leaf pine, are not durable unless 
 treated with preservatives. Loblolly pine because of its cheapness 
 and ease of impregnation is very desirable if preservative treatment 
 is contemplated. Moreover, its distribution, ease of reproduction, 
 and rapidity of growth insure a steady and cheap supply. 
 
 When this timber is used it is necessary to treat the entire pole 
 instead of only the butt, as in case of the species previously discussed, 
 especially in the warmer and more humid localities of the South. The 
 pressure method has ordinarily been used at commercial plants, but 
 good results are obtained in the treatment of loblolly and other sap 
 pines without pressure, or with very light pressure. A nonpressure 
 plant, designed by the Forest Service for the treatment of poles, was 
 recently erected at Winnfield, La. A penetration of 2 inches in sea- 
 soned poles may be obtained, with an absorption of from 8 to 12 
 pounds of creosote per cubic foot. These results were obtained by 
 treatments consisting of an initial hot bath, a short cold bath, and a 
 final heating. From four to five hours are required for the treat- 
 ment., which permits two runs per day, working one shift only. 
 Plate IV shows a cross section of a pole which had received a treat- 
 ment of 10 pounds per cubic foot and showed an average penetration 
 of If inches. 
 
30 PRESERVATIVE TREATMENT OF POLES. 
 
 CYPRESS. 
 
 Cypress is usually considered a durable wood, and the heartwood 
 is, in fact, one of the most durable of our native species. The sap- 
 wood, however, decays quickly, and this seriously weakens the pole. 
 The width of the sapwood on pole-size trees is from three-fourths of 
 an inch to lj inches. While no tests have been made by the Forest 
 Service, it is understood that the sapwood of cypress is easily impreg- 
 nated. The treatment should extend high enough to prevent rank 
 grass or bushes from coming in immediate contact with untreated 
 wood, as decay, if it once gets a foothold in the sapwood, seems to 
 have a tendency to extend upward on the pole. Cases have been 
 called to the attention of the Forest Service where the sapwood of 
 cypress poles deteriorated through the work of insects while the poles 
 were piled awaiting shipment. If the bark is completely removed 
 and the piles are open on skids over dry ground or raised out of reach 
 of the water in swamps, this trouble may usually be avoided. 
 
 DESIGN AND OPERATION OF POLE-TREATING PLANTS. 
 
 EXPERIMENTAL PLANTS. 
 
 In the first experiments the tank was shallow with a sloping bottom, 
 and the poles were placed in it at such an angle that the butts were 
 submerged to a height of 7 or 8 feet. (See PI. I, fig. 2.) The tank 
 was substantially built of iron and was sunk nearly level with the sur- 
 face of the ground, a fire box being first excavated underneath. No 
 derrick is required for handling the poles when a tank of this character 
 is used. A team is employed for skidding the poles alongside the 
 tank, from where they may be rolled into- position across the tank and 
 the butt submerged by supporting the top at the required height. 
 While this type of plant makes a cheap outfit for treating a small 
 number of poles, it has many defects, among which are the large 
 amount of oil required to fill the tank in proportion to its treating 
 capacity and the large surface of oil exposed to evaporation. 
 
 The tank used in the experimental treatment of cedar poles at Wil- 
 mington, Cal., is shown in figure 3. This is an upright cylindrical 
 tank 7 feet in diameter and 8 feet deep, constructed of one-fourth- 
 inch iron. 
 
 A framework around the tank is used to support the poles in an 
 upright position, and a false bottom, studded with short blunt spikes, 
 prevents them from slipping. A derrick or ginpole operated by a 
 power hoist is used for lifting them into and out of the tank. At the 
 plant shown in the illustration an electric hoist furnished the power. 
 The heating was at first done with a petroleum burner underneath the 
 tank, but later a steam boiler was installed, and steam coils placed in 
 
RESULTS OF TREATMENTS. 
 
 31 
 
 the tank. Twenty 40-foot 
 poles could be placed in 
 the tank at one time, 
 but, as most of the treat- 
 ments were made by heat- 
 ing and cooling in the 
 same tank without change 
 of oil, the capacity was 
 limited to one run a day. 
 This type of plant may 
 be used for treating poles 
 commercially where but 
 comparatively few poles 
 are to be treated. A stor- 
 age tank with sufficient 
 capacity to store at least 
 one carload shipment of 
 creosote should be added, 
 and the capacity of the 
 plant may be increased 
 by the addition of a 
 steam pump for changing 
 the oil at the end of the 
 hot bath, thus reducing 
 the time required for the 
 treatment. The entire 
 cost of the plant with the 
 improvements suggested 
 would be about $1,000 or 
 $1,200. A plant of this 
 type, but of somewhat 
 larger capacity, was sub- 
 sequently built by the 
 Forest Service at Norrie, 
 Colo. 
 
 COMMERCIAL PLANT FOR 
 BUTT TREATMENTS. 
 
 A general plan of a pro- 
 posed plant for the butt 
 treatment of poles on a 
 large scale is shown in 
 figure 4. This plant com- 
 bines the best features 
 
 Fig. 3. — Open tank and ginpole used in experimental pole 
 treatments. 
 
32 PRESERVATIVE TREATMENT OF POLES. 
 
 of the experimental plants with additional labor-saving appliances 
 necessary for the economical operation of a commercial plant. This 
 plant is equipped with two treating tanks, each 7 by 9 feet and 9£ 
 feet deep, and with an estimated capacity of thirty 8-inch 40-foot 
 western yellow pine or red cedar poles. The daily capacity, fig- 
 ured on a basis of two charges for each tank, is 120 poles. Two 
 storage and measuring tanks are provided, holding about 12,000 
 gallons of oil each. These tanks are designed with a relatively small 
 diameter in proportion to their height, so as to allow more accurate 
 gauging of the amount of oil used in the treatments. The plant is 
 designed to be operated by changing the oil at the end of the hot 
 bath, and in order that the change may be made quickly a receiving 
 tank is provided. Hot oil from the treating tank is run into the 
 receiving tank and the treating tank is then refilled from the cooler 
 oil in the storage tanks. From the receiving tank the oil is returned 
 to the storage tanks by means of a steam pump. The connections 
 may be so made that one storage tank may be used exclusively for 
 hot oil and the other for cold. Also, the oil may be transferred 
 directly from one treating tank to the other. Such an arrangement 
 will save fuel and will reduce the time required for treatment. A few 
 coils of steam pipe should be placed in the storage and receiving 
 tanks for keeping the oil in liquid condition, while in the treating 
 tanks sufficient steam coil is required to heat the oil rapidly during 
 the treatments. A boiler of about 50 horsepower capacity will be 
 required for heating and power purposes. A plant of this type is 
 suitable for erection at a central yard, where from 5,000 to 30,000 or 
 more poles are handled yearly. The cost of the plant, erected, will 
 vary between $4,000 and $5,000, depending on the locality. 
 
 Cost of Operation. — Following is a detailed statement of the 
 estimated cost of pole treatment, based on a daily capacity of 120 
 poles and a total yearly output of 30,000 poles: 
 
 LABOR PER DAY. 
 
 1 yard foreman $4. 00 
 
 1 plant engineer 4. 00 
 
 1 stationary engineer 4. 00 
 
 2 firemen, at $2.50 5. 00 
 
 5 laborers, at $2 10. 00 
 
 Total : --- 27.00 
 
 Labor charge per pole $0. 225 
 
 FUEL PER DAY. 
 
 2 tons coal, at $4 $8. 00 
 
 Fuel charge per pole ■ 067 
 
72742°— Bull. 84—11. (To face page 32.) 
 
 Fig. i— Plan of a commercial plant for the butt treatment of 
 
U. S. DEPT. OF AGRICULTURE 
 FOREST SERVICE 
 
 GENERAL ARRANGEMENT OF LOW PRESSURE TREATING PLANT 
 
 PREPARED FOR PUBLICATION 
 
 72742°— Bull. 84—11. (To face page 32/ 
 
 Fig. 5.— Plan of a commercial plant where the entire pole is to be treated. 
 

RESULTS OF TREATMENTS. 33 
 
 MAINTENANCE PER YEAR. 
 
 Depreciation and repairs $500. 00 
 
 Interest on investment in plant and preservatives 400. 00 
 
 Total 900. 00 
 
 Maintenance charge for pole $0. 030 
 
 Seasoning charge per pole (interest on investment) 100 
 
 Total treating charge, exclusive of preservative ° . 422 
 
 The total cost of treatment, exclusive of preservative, based on a 
 liberal estimate for all charges, is thus seen to be $0,422 per pole. 
 In the discussions of cost of treatments this charge is called $0.45. 
 
 DESIGN OF PLANT FOR TREATMENT OF THE ENTIRE POLE. 
 
 The principles of the nonpressure process are the same whether 
 the entire pole or only the butt is treated, only the design of the plant 
 being changed When the entire pole is to be treated, in place of the 
 open upright tanks, a horizontal cylinder is used, into which trucks 
 bearing the timber are admitted through doors opening on the ends, 
 the doors being hermetically closed after the timber is admitted. This 
 cylinder is similar in appearance to those used at pressure plants, but 
 is constructed of lighter metal. The storage tank, receiving tank, 
 and pump are arranged in a manner similar to those in the butt- 
 treating plant. 
 
 It is recommended, however, that where a plant is erected for the 
 treatment of the entire pole, it be of the low-pressure type in pref- 
 erence to the nonpressure. A treating cylinder capable of withstand- 
 ing a maximum pressure of 70 pounds to the square inch may be 
 constructed at a cost little in excess of a nonpressure cylinder, and 
 the other apparatus is essentially the same, with the addition of a 
 pressure pump. In operating the low-pressure plant, the preliminary 
 hot bath is given as for a nonpressure treatment; at the completion 
 of the hot bath, the retort may be refilled with cooler preservatives 
 and pressure applied until the desired absorption has been obtained. 
 
 The general design of a low-pressure plant is shown in figure 5. 
 The treating cylinder in this plant is 50 feet long and is capable of 
 holding about eighty-five 25-foot poles. Two runs per day of ten 
 hours were made, giving a daily capacity of 170 poles, which may be 
 further increased by operating the plant twenty-four-hour days. The 
 treating charge at a plant of this type, exclusive of preservative, will 
 average about 2 cents per cubic foot of timber. A plant similar to 
 the one shown in the figure costs about $10,000. 
 
 a In this estimate no charge is included for unloading and loading poles from and to 
 railway cars, it being assumed that the plant is operated in connection with a storage 
 or distributing yard. 
 
34 
 
 PRESERVATIVE TREATMENT OP POLES. 
 
 COST OF POLE TREATMENTS. 
 
 The cost of the treating operations having been set forth, and the 
 amount of preservative applied having been given, it remains now 
 only to compute the cost of the preservatives and to add to this the 
 cost of application in order to get the total cost. 
 
 Tank Treatment with Creosote. — -The cost of creosote in car- 
 load lots (including transportation) may be placed at 10 cents per 
 gallon for points east of the Mississippi River and in the vicinity of 
 the Gulf ports west of the Mississippi. West of the Rocky Mountains 
 the cost may be placed at 20 cents per gallon. The cost of applying 
 the treatment will vary greatly in different regions, owing to the dif- 
 erence in wage scales, but for convenience the general average already 
 estimated will be used in all cases. 
 
 Table 19. — Examples of cost per pole of open-tank treatments with creosote (estimated). 
 
 BUTT TREATMENT ONLY. 
 
 Species. 
 
 Size of pole. 
 
 Amount of creo- 
 sote applied. 
 
 Cost of treatment. 
 
 Diameter. 
 
 Length. 
 
 Per cubic 
 foot. 
 
 Per pole. 
 
 Preser- 
 vative, a 
 
 Opera- 
 tions. 
 
 Total. 
 
 
 Inches. 
 7 
 7 
 8 
 8 
 8 
 7 
 
 Feet. 
 30 
 
 30 
 40 
 40 
 40 
 35 
 
 Pounds. 
 
 Pounds. 
 25 
 50 
 
 37.5 
 62.5 
 39 
 35 
 
 Dollars. 
 0.30 
 .60 
 .90 
 1.45 
 .90 
 .80 
 
 Dollar. 
 0.45 
 .45 
 .45 
 .45 
 .45 
 .45 
 
 Dollars. 
 0.75 
 
 
 
 1.05 
 
 Western yellow pine 
 
 Do 
 
 6 
 10 
 6 
 
 1.35 
 1.90 
 1.35 
 
 
 1.25 
 
 
 
 
 ENTIRE POLE TREATMENT. 
 
 Loblolly pine. 
 Do 
 
 5 
 
 25 
 
 10 
 
 80 
 
 .95 
 
 .15 
 
 6 
 
 35 
 
 10 
 
 180 
 
 2.10 
 
 .35 
 
 1.10 
 
 2.45 
 
 a A gallon of creosote is estimated to be 8J pounds. 
 
 The sizes of poles mentioned in this estimate are those mostly used 
 in the experimental treatments. On account of the greater taper of 
 chestnut and northern white cedar the 30-foot poles of these species 
 take up about the same lateral space in the treating tank as 40-foot 
 poles of the western cedar and yellow pine. Lodgepole pine tapers 
 but little, and while greater tank capacity would be secured in the 
 treatment of 35-foot poles of this species than for the other species 
 and sizes named, the gain in this respect is more than offset by the 
 high wage rate prevailing throughout the Rocky Mountain region. 
 
 Tank Treatment with Zinc Chlorid. — The use of zinc chlorid as 
 a preservative has been discussed in connection with the treatment 
 of western red cedar and yellow pine poles. Supposing that the 
 customary half pound of salt to the cubic foot of timber is applied 
 and that the cost of operations is the same as for creosote treatment, 
 
INCREASED LIFE AFFORDED. 35 
 
 the cost for the butt treatment of 40-foot poles of either of these 
 species would be approximately 65 cents. 
 
 Tank Treatment with Crude Petroleum. — Crude petroleum 
 was used in the treatment of western yellow pine poles. With an 
 application of 9 pounds of oil to the cubic foot (about 8 gallons per 
 pole) and estimating the cost of the treating operations as before, 
 the total cost of a butt treatment with this preservative is about 85 
 cents. 
 
 Brush Treatment. — The labor cost of applying a brush treatment 
 is about 5 cents for each coat if the poles are treated on the skidways. 
 From one-half to 1 gallon of creosote per pole will be required, de- 
 pending on the timber and the thoroughness of the treatment. The 
 total cost of a brush treatment with creosote, applying two coats, is 
 therefore from 15 to 20 cents in the East and from 20 to 30 cents 
 in the West. However, if the creosote be purchased in small quan- 
 tities, as will usually be the case for brush treatments, the price will 
 be higher than that used in these estimates. 
 
 INCREASED LIFE AFFORDED BY PRESERVATIVE TREATMENT. 
 
 Before deciding on the use of a preservative treatment, the pole user 
 naturally wishes to know what length of life may be expected from 
 the treated timber. In any discussion of this question it is well to 
 keep clearly in mind what character of treatment is meant. Brush 
 coatings of preservatives usually amply repay their cost if an increase 
 of one to two years is added to the natural life of the untreated 
 timber, but a great degree of permanency in the protection afforded 
 should not be expected from application of so small a quantity of 
 preservative. However, results already obtained in these tests indi- 
 cate that an averaged increased life of at least three years may be 
 expected from brush applications of good wood preservatives. 
 
 If, instead of a light surface application, the butt of a pole be more 
 deeply impregnated with the preservative, the pole will probably 
 be limited by the life of the top rather than by the life of the butt. 
 There are practically no data on the ultimate life of the upper portion 
 of the pole, since replacements are commonly made because of failure 
 of the butt. The fact that almost all pole failures are due to butt 
 decay is a convincing argument for the efficiency of this form of treat- 
 ment. A life of twenty years for butt-treated chestnut and western 
 cedar and of twenty-two years for northern white cedar poles is 
 believed to be a conservative estimate, and in the drier western 
 climate it is believed that butt-treated pine poles may be depended 
 on to give twenty years' service. 
 
 While the information relative to the life of poles which have been 
 treated entire is more extensive than with regard to those which 
 have received butt treatment, this also is meager. The develop- 
 
36 
 
 PRESERVATIVE TREATMENT OF POLES. 
 
 ment of the ereosoting industry in this country is quite recent ; how- 
 ever, authentic instances are on record of creosoted pine poles which 
 have been in service twenty years and longer and are still apparently 
 as good as when first set. Records of the German Postal and Tele- 
 graph Department a covering fifty-two years show an average life of 
 20.6 years for creosoted pine poles. 
 
 FINANCIAL SAVING. 
 
 Closely related to the increased life afforded by preservative treat- 
 ment is the matter of the saving in money. The treatment adds to 
 the cost of the pole, but also increases the length of its service. The 
 question reduced to its simplest form is, Does the increased life repay 
 the cost of treatment? The comparison may best be made on the 
 basis of annual cost; that is, the initial cost of the pole divided by 
 the number of years' service it is expected to render, allowing a reason- 
 able rate of interest in the computation. The computations in Table 
 20 are made on a basis of 5 per cent interest. 
 
 Table 20. — Estimated financial saving due to creosote treatment of poles. 
 
 
 Size of pole. 
 
 Character of treat- 
 ment. 
 
 ft03 a 
 
 +3^ ft 
 
 PI <S-r} 
 gfc| 
 g£ft 
 
 s a 
 
 cd+3 
 pi '-< 
 
 .5 ^ 
 to "8 
 
 O — 
 
 o 
 
 CD o 
 PI o 
 "Soft 
 
 •a 
 
 ^ CD 
 +3 ^ 
 
 e3~ 
 
 3 ° 
 
 •2 s 
 
 at PI 
 
 o 
 
 o 
 
 "3 
 pi 
 pi 
 pi 
 ■< 
 
 
 Species. 
 
 u 
 
 CD 
 CD 
 
 5 
 
 a 
 
 3 
 
 O 
 
 lis 
 
 
 In. 
 
 7 
 
 7 
 
 7 
 
 8 
 
 8 
 7 
 6 
 
 Feet. 
 30 
 
 30 
 
 30 
 
 40 
 
 40 
 35 
 35 
 
 
 Lbs. 
 
 Dolls. 
 
 Dolls. 
 6.00 
 6.20 
 6.75 
 
 5.00 
 5.20 
 5.95 
 
 7.00 
 7.20 
 8.05 
 
 9.50 
 
 9.80 
 10.85 
 
 8.00 
 8.30 
 9.90 
 
 7.00 
 8.25 
 
 2.50 
 4.95 
 
 Yrs. 
 
 10 
 13 
 16 
 
 10 
 13 
 
 18 
 
 14 
 17 
 22 
 
 10 
 13 
 20 
 
 3 
 
 5 
 20 
 
 g 
 
 20 
 
 3 
 
 20 
 
 Dolls. 
 
 0.77 
 
 .66 
 
 .62 
 
 .65 
 .55 
 .51 
 
 .71 
 
 . .64 
 .61 
 
 1.23 
 1.04 
 
 .87 
 
 2.94 
 1.92 
 
 .79 
 
 1.62 
 .66 
 
 .92 
 .40 
 
 Dolls. 
 
 
 ■J Brush treatment 
 
 (Open-tank treatment. . 
 
 7 
 25 
 
 0.20 
 .75 
 
 0.11 
 
 
 .15 
 
 Southern white cedar 
 
 < Brush treatment 
 
 [Open-tank treatment. . 
 
 5 
 40 
 
 .20 
 .95 
 
 .10 
 .14 
 
 Northern white cedar 
 
 ] Brush treatment 
 
 [Open-tank treatment. . 
 
 5 
 50 
 
 .20 
 1.05 
 
 .07 
 .10 
 
 
 1 Brush treatment '. 
 
 1 Open-tank treatment. . 
 
 8 
 40 
 
 .30 
 1.35 
 
 .19 
 
 
 .36 
 
 Western yellow pine 
 
 •j Brush treatment 
 
 [Open-tank treatment.. 
 
 6 
 60 
 
 .30 
 1.90 
 
 1.02 
 2.15 
 
 
 \Open-tank treatment. . 
 
 40 
 
 1.25 
 
 
 
 .96 
 
 
 < Entire pole, open tank 
 ( or pressure. 
 
 200 
 
 2.45 
 
 .52 
 
 
 
 The financial saving is seen to be greater when treatment is applied 
 to poles having little natural durability than when applied to long- 
 lived timbers. This is due to two main reasons: (1) The annual 
 cost of nondurable poles used untreated is relatively very high because 
 
 "Archiv fur Post und Telegraphie, Nr. 16, Berlin, August, 1905. 
 
FINANCIAL SAVING. 37 
 
 of the frequent replacements required, and (2) the cost of the treat- 
 ment is relatively less (when interest on the investment is included), 
 since a shorter time must elapse before the benefits begin to be realized. 
 It is also obvious that, where the initial cost of the timber and of the 
 setting are high, prolonging the life of poles results in greater financial 
 benefit than when these costs are more moderate. 
 
 In Table 20 the annual cost of treated and untreated poles is com- 
 pared, assuming as a basis of the computations representative values 
 in typical localities for each species. For example, the cost of a 
 western red cedar pole is taken at southern California coast cities, 
 of lodgepole pine in the Rocky Mountain region, and of loblolly pine 
 in the South. Sometimes it is of greater interest to compare the cost 
 of different species in the same locality, and especially to compare an 
 untreated pole of a durable species with a treated pole of an ' 'inferior" 
 species. 
 
 A 7-inch 35-foot lodgepole pine pole is worth $3 f. o. b. cars in the 
 mountain region of Colorado. Recently an Idaho cedar pole of the 
 same size could be obtained in the same region for $5.25, including 
 transportation. A butt treatment for the pine pole will cost $1.25, 
 making the total cost of the treated pole $4.25. Let it be assumed, 
 however, that owing to local freights the first cost of the untreated 
 cedar and the treated pine at the point of use will be the same, namely, 
 $5.25. Setting, which is very costly in a mountainous region, may 
 be figured at $4, making the cost of either pole in place $9.25. Assum- 
 ing that the untreated cedar will last in this region fifteen years, and 
 the treated pine twenty years, the annual costs of the two poles 
 become $0.89 and $0.74, respectively, or an annual saving of $0.15 in 
 favor of the pine pole. At the rate of forty poles to the mile this 
 will amount to a saving of $6 each year for each mile of line in 
 operation. 
 
 In the vicinity of Fresno, Cal., a 40-foot cedar pole brought from 
 Washington costs $8, while a native pine pole may be obtained for $5. 
 A heavy butt treatment of creosote may be given the latter for $1.90, 
 making the total cost $6.90. Allowing $3 for setting in either case, 
 the respective costs of the poles in line are $11 and $9.90. Pole users 
 in this locality estimate the life of cedar at ten years, while it is be- 
 lieved that the treated pine will last twenty years. On this basis the 
 respective annual costs of the two poles are $1.42 and $0.79, an 
 annual saving of $0.63 on every native treated pole in use. In this 
 case there is a saving even in the first cost, and a relatively greater 
 saving when the lives of the two poles are compared. 
 
38 PRESERVATIVE TREATMENT OF POLES. 
 
 RELATION OF PRESERVATIVE TREATMENTS TO POLE SPECIFI- 
 CATIONS. 
 
 It is the practice in pole specifications to require poles of larger 
 diameter than the actual service requires, in order that a certain 
 amount of deterioration by decay shall be allowable before replace- 
 ment is needed. For example, if it is computed that a circumference 
 of not less than 28 inches of sound wood in the pole at the ground line 
 is required to support the strain to which the line is liable to be sub- 
 jected, and the poles used have a circumference of 36 inches at the 
 ground line, then 8 inches deterioration, or the equivalent of a depth 
 of decay of approximately 1J inches, is allowable before replacement 
 is required. 
 
 In some species otherwise durable the sapwood decays very 
 quickly. Untreated white cedar poles in Georgia, inspected after 
 being set in line four years, showed from 45 to 50 per cent of the 
 number with sapwood completely decayed at the ground line, which 
 amounted to an average deterioration of 4 inches in the circumfer- 
 ence, equivalent to an average depth of decay of fully five-eighths of 
 an inch. Cypress poles in Florida, inspected after being in the ground 
 seven years, showed an average depth of decay of 0.8 inch at the 
 ground line. The heartwood of these poles is sound, and in nearly 
 all cases is of sufficient dimension to meet the requirements of the line 
 in which they are used, although, graded by the butt circumference, 
 they fall decidedly lower than their original class. If there had been 
 used originally poles of the grade represented by these after the sap- 
 wood has decayed, and if the butts had been well treated with creo- 
 sote, so that their full size and strength would be maintained, not only 
 would the poles be equally strong with those now in use, but their 
 ultimate length of life would be greater, and the difference in cost 
 between the two grades of poles would in some cases offset the cost 
 of the treatment. Pole users are, therefore, paying money that 
 might more profitably be spent for preservative treatment for poles 
 of large diameter in order to secure longer life in that way. In short, 
 the possibility of using lighter poles and giving them preservative 
 treatment, so as to maintain their full size and strength, merits the 
 attention of all pole users. 
 
 GROWTH AND FORM OF POLES. 
 
 Table 2 1 gives the average time required for poles of various species 
 and sizes to grow; also the natural, taper of such poles, as shown by 
 circumference measurements at the ground line of the pole when set 
 (6 feet from the butt of the pole) and at the top. The table is com- 
 piled in part from measurements made on poles used in the seasoning 
 and treating tests and in part from other commercial tree studies of the 
 Forest Service. 
 
SUMMARY. 
 
 Table 21. — Form and rate of growth of 'pole timber. 
 
 39 
 
 Species. 
 
 Location. 
 
 Nominal 
 sizes of poles. 
 
 Diam- 
 eter. 
 
 Length. 
 
 Age. 
 
 Circum- 
 ference 
 
 at 
 ground 
 line of 
 pole.a 
 
 Circum- 
 ference 
 at top. 
 
 Amount of 
 taper on circum- 
 ference. 
 
 Ground 
 line to 
 top.a 
 
 Aver- 
 age each 
 10 feet. 
 
 Chestnut: 
 
 Grown from seed . 
 
 Grown from 
 
 sprout 
 
 Northern white cedar. 
 Western yellow pine. . 
 
 Lodgepole pine 
 
 Loblolly pine 
 
 Western red cedar 
 
 Maryland, 
 .do. 
 
 •Northern Michigan 
 
 Madera County, Cal . . . 
 
 Montana 
 
 Texas 
 
 Western Washington. . 
 
 Inches. 
 7 
 
 Feet. 
 30 
 
 30 
 30 
 40 
 35 
 35 
 40 
 
 Years. 
 56 
 
 51 
 190 
 65 
 90 
 30 
 82 
 
 Inches. 
 37.3 
 
 37.6 
 36.4 
 38.6 
 30.8 
 28.9 
 38.9 
 
 Inches. 
 27.8 
 
 28.4 
 23.9 
 25.1 
 22.0 
 22.0 
 27.0 
 
 Inches. 
 9.5 
 
 9.2 
 12.5 
 13.5 
 8.8 
 6.9 
 11.9 
 
 Inches. 
 4.0 
 
 3.8 
 5.2 
 4.0 
 3.0 
 2.4 
 3.5 
 
 a 6 feet from butt. 
 
 A striking contrast appears in this table between the rate of growth 
 of northern white cedar and loblolly pine. The cedar, under natural 
 forest conditions, is a very slow-growing tree and will become increas- 
 ingly scarce as a source of pole supply, as present stands become more 
 and more exhausted. On the other hand, loblolly pine is a good 
 example of a number of more rapid-growing species which, possessing 
 all essential qualities for poles except durability — a defect which may 
 be overcome by preservative treatment — will, through their rapidity, 
 of growth and ease of reproduction, continue to be available in suffi- 
 cient quantities and at moderate prices, thus assuring pole users of 
 supplies for future needs. 
 
 SUMMARY. 
 
 The more important conclusions from the investigations discussed 
 in this bulletin are: 
 
 Seasoning of poles reduces their weight, commonly from 16 to 30 
 per cent, and even more for some species, with a corresponding 
 decrease in the cost of transportation. Thorough seasoning is essen- 
 tial if the poles are to be treated with preservatives. 
 
 In general, poles cut during the spring and summer lose weight 
 most rapidly. Poles cut during autumn and winter lose weight less 
 rapidly, but more regularly. Too rapid seasoning may be detrimental 
 to the timber by causing excessive checking. 
 
 Shrinkage of poles during seasoning is very slight, and does not 
 exceed 1 per cent on the circumference. 
 
 A simple and inexpensive way of using a preservative consists in 
 applying it to the surface of the pole with a brush. Butt treatments 
 made in this manner with a good preservative may be expected to 
 add two to three years to the life of the poles and more than repay 
 their cost, but are not as effective as impregnating the wood with the 
 preservative. 
 
40 PRESERVATIVE TREATMENT OF POLES. 
 
 Impregnation of many pole timbers, especially the sapwood of 
 round timbers, may be successfully accomplished in open tanks, 
 without the use of artificial pressure, by immersions in hot and cold 
 preservative, the cold following the hot. 
 
 The open-tank process for the treatment of poles has the advan- 
 tage that it is possible to apply the preservative to the butts only, 
 with a great saving in the amount used. Plants for butt treatments 
 may be constructed in a simple and inexpensive manner. 
 
 Preservative treatment is profitable financially, the increased 
 durability of the timber decreasing the annual service charge. Rela- 
 tively greater benefits are derived from the treatment of nondurable 
 woods than from the treatment of those which possess great natural 
 durability. 
 
 Preservative treatment makes possible the use of poles of smaller 
 butt circumference, since allowances usually made for deterioration 
 by decay need not be considered, when it is certain that the full size 
 and strength of the poles will be retained through a long period of 
 years. 
 
 By the application of preservative treatment, many species of 
 timber not naturally durable and formerly not considered suitable 
 for poles may be used for this purpose, thus opening up new sources 
 of supply, and greatly relieving the pole situation from the threatened 
 exhaustion of those woods now most commonly used. 
 
APPENDIX. 
 
 REPORT ON INSPECTION OF EXPERIMENTAL POLES. 
 
 In the summer of 1905 a number of treated and untreated poles 
 were set in the Augusta-Savannah and Helena-Meldrin a lines of the 
 Southern Bell Telephone and Telegraph Company, near Savannah, 
 Ga. The experiment dealt with 816 poles, one half southern white 
 cedar and the other half chestnut, the treated poles being alternated 
 with the untreated ones, and the series arranged as shown in the 
 following plan: 6 
 
 Table 22. — Setting plan of poles in experimental line established in cooperation with the 
 Southern Bell Telephone and Telegraph Company near Savannah, Ga. 
 
 Pole 
 No. 
 
 Preservative a sold as — 
 
 Condition. 
 
 Pole 
 
 No. 
 
 Preservative a sold as — 
 
 Condition. 
 
 1 
 
 Avenarius Carbolineum 
 
 Seasoned. 
 
 Do. 
 
 Do. 
 Green. 
 Seasoned. 
 
 Do. 
 
 Do. 
 Green . 
 Seasoned. 
 
 Do. 
 
 Do. 
 Green. 
 Seasoned. 
 
 Do. 
 
 Do. 
 Green. 
 Seasoned. 
 
 18 
 19 
 20 
 21 
 22 
 23 
 24 
 25 
 26 
 27 
 28 
 29 
 30 
 31 
 32 
 33 
 34 
 
 
 Seasoned. 
 
 2 
 
 
 Do. 
 
 3 
 
 Avenarius Carbolineum 
 
 No treatment 
 
 
 4 
 
 Imperial Wood Preservative 
 
 
 5 
 
 S. P. F. Carbolineum 
 
 Do. 
 
 6 
 
 
 Imperial Wood Preservative 
 
 Do. 
 
 7 
 
 S. P. F. Carbolineum 
 
 Do. 
 
 8 
 
 
 Do. 
 
 9 
 
 
 
 Do. 
 
 10 
 
 
 
 Do. 
 
 11 
 
 
 
 
 1? 
 
 
 Tar 
 
 
 13 
 
 
 
 Do. 
 
 14 
 
 No treatment 
 
 Tar 
 
 Do: 
 
 15 
 
 
 
 
 16 
 
 No treatment 
 
 Tar 
 
 Do. 
 
 17 
 
 
 
 
 
 
 
 
 a See page 46 for analysis of preservatives. 
 
 The series is repeated twelve times for each species, series No. 2 
 beginning with pole No. 35, series No. 3 with pole No. 69, etc. 
 
 The inspection of the line was made in April and May, 1909, by 
 representatives of the American Telegraph and Telephone Company 
 and of the Forest Service. A careful examination was made of each 
 pole and its condition noted. In Tables 23 and 24 and in figure 6 
 the relative efficiencies of the various treatments are compared by 
 grouping the poles with reference to the amount of decay in the 
 sapwood at or near the ground line. The number and percentage 
 of poles having decay in the heartwood is also shown in the tables. 
 
 a In Forest Service Circular No. 104 the line is referred to as the "Savannah- 
 Abbeville-Eastman " line. 
 
 b See "Southern white cedar," page 20, and "chestnut," page 18, for record of 
 treatments. 
 
 41 
 
42 
 
 PRESERVATIVE TREATMENT OF POLES. 
 
 
 SOUTHERN WH 
 
 ITE CEDAR 
 
 TAP COAT/NO (GPEEN POLES) 
 ONTPEATED (SEASONED POLES) 
 TAP OOAT/NS (SEASONED POLES) 
 l/A/TPEATEL/ (GPEEN POLES) 
 
 PRESERVATII/E SOLD AS 
 
 CPEOL/A/ 2 COATS 
 
 PRESERVA T/VE SOLD AS 
 
 S.P.P. CAPBOL/NEUM(/ COAT) 
 
 PRESERVATIVE SOLD AS 
 
 /MPEPJAl WOOD PPESEPVAT/vE^ 2 COATS 
 
 PRESERVATIVE SOLO AS 
 
 S.PE CAflBOL/NEUM (2 COATS) 
 
 PRESERVATIVE SOLD AS 
 
 AfENAP/VS CAPBOL/NEDM, 2 COATS 
 
 PRESERVA Tl VE SOLD AS 
 
 SP/P/TT/NE, S COATS 
 CPEOSOTE, .3 CO/ITS 
 CPEOSOTE, 2 COATS 
 
 
 
 
 
 
 
 
 
 
 
 
 fe:tf:'« 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ssaws 
 
 
 
 
 
 ■:::| 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 EsJ^ 
 
 
 
 
 
 •.•■.•!•;•! 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 US*; 
 
 »5%SS? 
 
 i^i^ 
 
 f^&4 
 
 ^^ 
 
 ^■•>: 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 t 
 
 7 /O 20 SO 40 SO 60 70 <SO JO /6 
 
 pepcene or poles 
 
 CHEST 
 
 O 
 
 NUT 
 
 
 ■XA 
 
 
 
 
 
 
 
 
 
 
 DNTPEATE//(SPEEN POLES) 
 l/NTPEATEO (SEASONED POLES) 
 TAP COAT/NG (GPEEN POLES) 
 P/NE TAP? 
 
 TAP COAT/A/G (SEASOA/EO POLES) 
 CPEOSOTE, 7 COAT 
 
 PRESERVATIVE SOLD AS 
 
 AVENAP/US CAPBOL/NEC/N, /COAT 
 
 PRESERVA TIVE SOLD AS 
 
 /MPEB/AL WOOD PPESEPMT//E, 2 COATS. 
 CPEOSOTE, 2 COATS 
 
 PRESERVATIVE SOLD AS 
 
 SP/P/TT/NE, 3 COATS 
 C/fEOSOTE, J COATS 
 
 PRESERVATIVE SOLD AS 
 
 CPEOL/A/, ^ COATS 
 
 PRESERVATIVE SOLD AS 
 
 S.P.P.CAPBOL/NEUM, 2 COATS 
 
 PRESERVATIVE SOLD AS 
 
 AvENAP/OS CARBOL/NENA/, 2 COATS 
 
 
 
 
 
 
 
 
 
 
 
 •1:W 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■zm? 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 VW 
 
 '■*& 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 W£& 
 
 *%*** 
 
 ■VS//, 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 B%# 
 
 V/Ssi- 
 
 y;s//s 
 
 %^ 
 
 ^^ 
 
 ;^^ 
 
 *fe^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 6 
 
 > /O 20 30 40 SO SO TO SO SO /C 
 PERCENT OE POLES 
 
 LEGE 
 
 ■■ 'SOCIAIO 1 1 
 
 S^Si LESS TrtA/V /O'A OP SAPWOOO |:*:-:-:*J 
 OECAYED (cEOAR POLES ) 
 
 Egg%3 PARTIAL DECAY 1 OE SAPWOOO 
 
 TOTAL DECAY OP SAPWOO0 
 
 HfOPE E//AAI 10 % OP" SAPWOOO 
 DECAYED (CEDA/? POLES) 
 
 (c//EsrA/t/r poles) 
 
 Fig. 6. — Diagram showing condition of experimental poles. 
 
APPENDIX. 
 
 43 
 
 It should not be inferred, however, that because a pole is classed 
 in the latter group decay is necessarily of a serious character, as in 
 most cases the amount of heartwood decayed is small. The class 
 indicates only that decay has extended beyond the sapwood portion 
 into the heartwood without regard to the amount of decay. A very 
 few of the poles were decayed to such an extent that replacement 
 was required. The number of such is also noted. 
 
 Table 23. — Summary of condition of southern white cedar poles in experimental line 
 established in cooperation with the Southern Bell Telephone and Telegraph Company 
 near Savannah, Ga. 
 
 Treatment. 
 
 Total 
 num- 
 ber. 
 
 Sound 
 poles. 
 
 10 per cent 
 or less of 
 sapwood 
 decayed. 
 
 More than 
 10 per cent; 
 less than 
 total decay 
 of sap- 
 wood. 
 
 Total 
 decay 
 of sap- 
 wood. 
 
 Decay in 
 heart- 
 wood. 
 
 Replace- 
 ment, 
 needed. 
 
 Untreated seasoned poles . . 
 
 Untreated green poles 
 
 Preservative sold as Ave- 
 narius Carbolineum (2 
 
 104 
 96" 
 
 24 
 
 21 
 
 3 
 33 
 15 
 
 24 
 
 24 
 
 24 
 12 
 24 
 
 No. 
 
 p.ct: 
 
 No. 
 1 
 
 7 
 
 7 
 5 
 
 P.ct. 
 1 
 
 7 
 
 29 
 24 
 
 No. 
 51 
 45 
 
 1 
 2 
 2 
 
 P.ct 
 49 
 47 
 
 4 
 9 
 67 
 
 No. 
 
 52 
 43 
 
 P.ct. 
 50 
 45 
 
 No. 
 6 
 2 
 
 1 
 
 P.ct. 
 
 6 
 2 
 
 4 
 
 No. 
 1 
 
 P.ct. 
 1 
 
 1 
 
 16 
 14 
 
 1 
 
 23 
 10 
 
 16 
 
 14 
 ' 5 
 
 1 
 
 67 
 67 
 
 33 
 
 70 
 67 
 
 67 
 
 5S 
 21 
 
 
 
 
 Preservative sold as S. P. 
 
 F. Carbolineum (2 coats). 
 Preservative sold as S. P. 
 
 F. Carbolineum (1 coat) . . 
 
 
 
 
 
 
 
 
 
 
 
 10 
 5 
 
 8 
 
 9 
 13 
 
 30 
 33 
 
 33 
 
 38 
 54 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Preservative sold as Spirit- 
 
 
 
 
 
 
 
 
 
 Preservative sold as Impe- 
 rial Wood Preservative 
 
 1 
 
 6 
 10 
 12 
 
 4 
 
 25 
 83 
 50 
 
 
 
 
 
 
 
 Preservative sold as Creo- 
 
 
 
 
 
 
 
 Coal tar (green poles) 
 
 Coal tar (seasoned poles).. . 
 
 2 
 
 11 
 
 17 
 46 
 
 
 
 
 
 
 
 1 
 
 4 
 
 
 
 
 
 
 
 
 
 
 
 Table 24. — Summary of condition of chestnut poles in experimental line established 
 in cooperation with the Southern Bell Telephone and Telegraph Company near Savan- 
 nah, Ga. 
 
 Treatment. 
 
 Total 
 num- 
 ber. 
 
 Sound 
 poles. 
 
 Partial de- 
 cay of sap- 
 wood. 
 
 Total de- 
 cay of sap- 
 wood. 
 
 Decay in 
 heartwood. 
 
 Replace- 
 ment, 
 needed. 
 
 Untreated seasoned poles 
 
 Untreated green poles 
 
 Preservative sold as Avenarius 
 Carbolineum (2 coats) 
 
 Preservative sold as Avenarius 
 Carbolineum (1 coat) 
 
 Preservative sold as S. P. F. Car- 
 bolineum (2 coats) 
 
 Preservative sold as S. P. F. Car- 
 bolineum (1 coat) 
 
 Creosote (1 coat) 
 
 Creosote (2 coats) 
 
 Creosote (3 coats) 
 
 Preservative sold as Spirittine (3 
 coats) 
 
 Preservative sold as Imperial 
 Wood Preservative (2 coats). . . 
 
 Preservative sold as Creolin (2 
 coats) 
 
 Coal tar (green poles) 
 
 Coal tar (seasoned poles) 
 
 Pine tar 
 
 114 
 95 
 
 18 
 
 4 
 
 18 
 
 2 
 3 
 39 
 
 6 
 
 24 
 
 24 
 
 24 
 
 8 
 
 21 
 
 7 
 
 No. 
 
 P.ct. 
 
 50 
 
 78 
 
 100 
 33 
 
 62 
 
 67 
 
 63 
 
 63 
 
 71 
 ..... 
 
 No. 
 12 
 
 7 
 
 1 
 1 
 3 
 
 P.ct. 
 11 
 7 
 
 6 
 
 25 
 
 17 
 
 No. 
 102 
 
 P.ct. 
 89 
 93 
 
 
 
 25 
 
 6 
 
 No. 
 70 
 35 
 
 P.ct. 
 61 
 37 
 
 No. 
 1 
 
 P.ct. 
 1 
 2 
 
44 PRESERVATIVE TREATMENT OE POLES. 
 
 DISCUSSION OF RESULTS. 
 
 SOUTHERN WHITE CEDAR POLES. 
 
 With the exception of the tar and creolin treatments and a few 
 treatments with only one coat of carbolineum or creosote, from 58 
 to 70 per cent of the treated cedar poles are in a perfect state of 
 preservation. On the other hand, the sapwood of the untreated 
 poles is in nearly every case completely or almost completely decayed, 
 and in a few cases the decay extends to the heartwood. While all 
 the poles having more than 10 per cent decay, yet less than total 
 decay of the sapwood, are put into one group, the proportion of 
 the untreated poles in this group that falls near the upper limits 
 in amount of decay found is much greater than that of the treated 
 poles. 
 
 When decay occurred in the treated poles (referring only to those 
 treatments which show a high percentage of sound poles) it was 
 found most often in sapwood which was not penetrated by the pre- 
 servative, the outer wood to a depth of perhaps a quarter of an inch, 
 or as deep as the preservative had penetrated, being in a sound 
 condition. Moreover, such decay was usually small in amount 
 and occurred in strips frequently only a few inches wide, extending 
 lengthwise of the pole. White ants, or termites, were very com- 
 monly found in the poles; like decay, their destruction was confined 
 largely to the untreated poles and to wood which the preservative 
 had not reached beneath the protecting bands of the treated poles. 
 These insects excavate galleries in the wood, and it is believed that 
 to a considerable extent they hasten decay.® However, as the borings 
 of the termites were in nearly all cases accompanied by decay, it 
 was usually impossible to determine which agency was primarily 
 responsible for the destruction, and in the tables no distinction is 
 made between these two causes of deterioration. N 
 
 The amount of deterioration was determined by measuring the cir- 
 cumference just above the decayed portion and the circumference of 
 the sound wood at the point of greatest decay, first scraping away 
 the disintegrated wood. The difference between these two measure- 
 ments gives the approximate amount of deterioration, which for 100 
 poles, having all the sapwood decayed, was on an average 4.03 inches. 
 This corresponds to an average depth of decay of approximately five- 
 eighths of an inch for these poles. Other poles similarly decayed, 
 but on which good measurements could not be obtained, are not 
 counted in this average. 
 
 ° It is stated by the Bureau of Entomology that white ants, while usually confining 
 their work to the outer layers of wood where there is incipient decay, will often com- 
 pletely honeycomb the sound wood of poles. 
 
APPENDIX. 
 
 45 
 
 CHESTNUT POLES. 
 
 The same general conditions apply to the chestnut poles, but decay 
 is less in amount, although the number of poles having decay of 
 heartwood is very much greater. The sapwood of chestnut is narrow 
 and its decay does not appreciably affect the strength of the pole. 
 Decay does not, however, halt when it reaches the heartwood, but 
 continues steadily, although probably at a decreased rate. The 
 average depth of decay on 222 chestnut poles having at least all of 
 the sapwood decayed was found to be 0.25 of an inch. 
 
 IRREGULARITIES IN RESULTS. 
 
 Several irregularities appear in the results of the tests as shown by 
 the tables ; these, however, may be regarded as largely accidental and 
 do not destroy the value of the whole. For example, two chestnut 
 poles were treated with only one coat of the preservative sold as car- 
 bolineum. Both are sound, and therefore the percentage of sound 
 poles under this head is 100. Eighteen poles were given two coats of 
 the same preservative ; of these 14, or 78 per cent, are sound. It is 
 not a necessary conclusion that one coat of this preservative is more 
 efficient than two coats, although it might be concluded that one coat 
 affords an effective treatment. Even the latter conclusion is not 
 entirely warranted after a comparison with the results obtained from 
 one and two coats of other preservatives and from one coat of the 
 same preservative on cedar poles. A somewhat similar case is shown 
 in the creosote treatments on cedar poles. Thirty-three were treated 
 with two coats of creosote and 15 with three coats. Seventy per cent 
 of those treated with two coats are sound and only 67 per cent of 
 those receiving three coats. The conclusion is not that two coats 
 are more efficient than three, but in the absence of other data we may 
 infer that a third coat does not add to the efficiency of the treatment. 
 
 HEIGHT OF DECAY ABOVE GROUND LINE. 
 
 The height above ground line to which decay extended was noted 
 on 301 cedar poles. On most the decay did not extend upward more 
 than one-half foot, and in relatively few cases did it extend more than 
 2 feet above ground, the height depending to a large extent on the 
 character of the vegetation in the immediate vicinity of the pole. 
 
 Table 25. — Height of decay above ground line — Cedar poles. 
 
 Height of decay above ground. 
 
 Number 
 of poles. 
 
 Per 
 cent. 
 
 
 205 
 96 
 46 
 18 
 5 
 
 68 
 32 
 15 
 6 
 2 
 
 
 
 
 
 
46 
 
 PRESERVATIVE TREATMENT OF POLES. 
 
 The sapwood of chestnut poles has a tendency to flake off, and the 
 surface of the poles is frequently scaly. Aside from this scaling off 
 of the sapwood, decay did not extend any appreciable distance above 
 the ground. 
 
 It appears from Table 25 that if cedar poles be treated to a height 
 of 2 to 3 feet above the ground, ample protection from decay will be 
 afforded. Treatment need not extend any higher on chestnut poles, 
 and possibly may be somewhat lower with safety. 
 
 DETERIORATION SHOWN BY CHANGE OF GRADES. 
 
 A grading of the untreated cedar poles was made, based on the butt 
 circumference given in the specifications of the American Telephone 
 and Telegraph Company and upon the measurements, already 
 described, of the poles after use. The number of poles in each class 
 graded by circumference above the decayed portion and the grading 
 of the same poles based on the circumference of sound wood at the 
 point of greatest decay is shown in Table 26: 
 
 Table 26. — Grading of -poles based on original butt circumference and circumference of 
 sound ivood at time of inspection. 
 
 Classes. 
 
 Number of 
 poles, 
 
 graded by 
 original 
 circum- 
 ference. 
 
 Number of poles, graded by circum- 
 ference of sound wood at time of 
 inspection, by classes. 
 
 A. 
 
 B. 
 
 c. 
 
 D. 
 
 E. 
 
 Below 
 E. 
 
 A 
 
 B 
 
 C 
 
 D 
 
 Total.... 
 
 56 
 70 
 35 
 18 
 
 16 
 
 31 
 
 27 . 
 
 9 
 
 32 
 
 9 
 
 
 
 
 9 
 10 
 5 
 
 1 
 6 
 4 
 
 1 
 
 10 
 9 
 
 
 
 
 
 
 179 
 
 16 
 
 58 
 
 50 
 
 24 
 
 11 
 
 20 
 
 Of the 179 poles included in the above classification, only 57 have 
 not been lowered in grade because of deterioration in circumference 
 due to decay. The remaining 122, or 68 per cent, have deteriorated 
 enough to require that they be classed at least one grade lower, and, 
 of these, 45 must be classed at least two grades lower, while of a few 
 the deterioration is even greater. 
 
 ANALYSIS OF PRESERVATIVES USED IN THE TREATMENT OF 
 POLES SET IN THE AUGUSTA-SAVANNAH AND HELENA-MELDRIN 
 LINES. a 
 
 Samples of the preservatives used for the treatment of experi- 
 mental poles in the Augusta-Savannah and Helena-Meldrin lines 
 were analyzed by the engineering department of the American Tele- 
 phone and Telegraph Company. These analyses were made in 
 
 a Reprinted from Forest Service Circular 104, with names of preservatives added. 
 
APPENDIX. 
 
 47 
 
 accordance with the company's methods for the analysis of creosote 
 and carbolineum standard at the time these treatments were made 
 (1905). The results of the analyses follow: 
 
 Preservative sold as Avenarius Carbolineum. a 
 
 Color 
 
 Specific gravity at 17° C. . . 
 
 Mineral matter 
 
 Flashing point 
 
 Burning point 
 
 Distillates: 
 
 Below 235° C 
 
 Loss 
 
 From 235° C. to 315° C 
 Residue above 315° C. 
 Solids, 1.7° C to 4.4° C 
 Tar acids 
 
 Red-brown... 
 
 1.121 
 
 0.160 
 
 137° C 
 
 164° C 
 
 0.41 per cent. . 
 0.19 per cent.. 
 19.16 per cent. 
 70.24 per cent. 
 No separation 
 1.12 per cent.. 
 
 Red-brown. 
 1.122. 
 0.050. 
 137° C. 
 168° C. 
 
 0.61 per cent. 
 0.22 per cent. 
 26.97 per cent. 
 72.20 per cent. 
 No separation. 
 1.16 per cent. 
 
 a Manufacturers' analysis: Color, red-brown; specific gravity at 21° C, 1.126; viscosity at 21° 0, 115.860; 
 mineral matter (ash), 0.047 per cent; flashing point, 127° C; burning point, 179° O; distillates — from 
 220° C. to 260° C, 4.5 per cent; rom 260° C. to 274° C, 1 per cent; from 274° C. to 302° C, 20 per cent; naphtha- 
 lene, very slight trace; mineral acids (HCl,H.2SO.i), very slight trace; phenols, very slight trace. 
 
 Preservative sold as S. P. F. Carbolineum. 
 
 Series I. 
 
 Series II. 
 
 Color 
 
 Specific gravity at 17° C. . . 
 
 Flashing point 
 
 Burning point 
 
 Distillates: 
 
 Below 235° C 
 
 Loss 
 
 From 235° C. to 315° C 
 
 Residue over 315° C... 
 Solids, 1.7° C. to 4.4° C... 
 
 Tar acids 
 
 Mineral matter 
 
 Red-brown... 
 
 1.134 
 
 135° C 
 
 163° C 
 
 0.35 percent.. 
 0.13 per cent.. 
 28.84 per cent. 
 70.68 per cent. 
 No separation 
 1.30 percent.. 
 0.31 percent.. 
 
 Red-brown. 
 1.134. 
 135° C. 
 162° C. 
 
 0.31 per cent. 
 0.19 per cent. 
 30.10 per cent. 
 69.40 per cent. 
 No separation. 
 1.30 per cent. 
 0.47 per cent. 
 
 Preservative sold as Spirittine. a 
 
 Series I. 
 
 Series II. 
 
 Color 
 
 Specific gravity at 17° C... 
 
 Flashing point 
 
 Burning point 
 
 Distillates: 
 
 Below 235° C 
 
 Loss 
 
 From 235° C. to 315° C 
 
 Residue above 315° C. 
 Solids, 1.7° C. to 4.4° C... 
 
 Tar acids 
 
 Mineral matter 
 
 Green-black. . 
 
 1.032 
 
 90°C 
 
 99° C 
 
 15.14 per cent. 
 0.65 per cent.. 
 26.23 per cent. 
 57.98 per cent. 
 No separation 
 15.40 per cent 
 0.14 per cent.. 
 
 Green-black. 
 1.031. 
 90° C. 
 101° C. 
 
 14.97 per cent. 
 0.53 per cent. 
 25.60 per cent. 
 58.90 per cent. 
 No separation. 
 16.30 per cent. 
 0.02 per cent. 
 
 a Manufacturers' analysis: Color, green-black; specific gravity, 1.03; flashing point, 78° C; burning 
 point, 93° C; distillates— below 315° C, 37.40 per cent; above 315° C, 52.69 per cent; coke and gas corre- 
 sponding to, 9.91 per cent. 
 
48 
 
 PRESERVATIVE TREATMENT OE POLES. 
 Coal-tar creosote. 
 
 Series I. 
 
 Series II. 
 
 Color 
 
 Specific gravity at 38° C... 
 
 Distillates: 
 
 Below 170° C 
 
 From 170° C. to 205° C 
 From 205° C. to 210° C 
 From 210° C. to 235° C 
 From 235° C. to 240° C 
 From 240° C. to 270° C 
 From 270° C. to 300° C 
 'Residue above 300° C. 
 Loss 
 
 Total 
 
 Naphthalene 
 
 Liquid at 
 
 Tar acids 
 
 Greenish-brown 
 1.035 
 
 0.17 per cent. 
 
 1.25 percent. 
 
 1.14 per cent. 
 43. 96 per cent . 
 
 6. 66 per cent. 
 19. 48 per cent. 
 10. 07 per cent. 
 17. 00 per cent. 
 
 0.27 per cent. 
 
 100. 00 per cent. 
 45.10 per cent.. 
 
 38° C 
 
 9 c. c 
 
 Greenish-brown. 
 1.035. 
 
 0. 09 per cent. 
 
 0. 70 per cent. 
 
 0. 74 per cent. 
 45. 92 per cent. 
 
 6. 12 per cent. 
 20. 03 per cent. 
 
 9. 61 per cent. 
 16. 30 per cent. 
 
 0. 49 per cent. 
 
 100. 00 per cent. 
 46.00 per cent. 
 38° C. 
 8.3 c. c. 
 
 Preservative sold as Imperial Wood Preservative. 
 
 Color 
 
 Specific gravity at 17° C. . . 
 
 Flashing point 
 
 Burning point 
 
 Distillates: 
 
 Below 235° C 
 
 Loss 
 
 From 235° C. to 315° C 
 
 Residue at 315° C 
 
 Solids 1.7° C. to 4.4° C 
 
 Tar acids 
 
 Mineral matter 
 
 Series I. 
 
 Series IT. 
 
 Greenish-black 
 
 Greenish-black. 
 
 1.035 
 
 1.035. 
 
 115° C 
 
 111° C. 
 
 129° C 
 
 123° C. 
 
 2.51 per cent 
 
 3.65 per cent. 
 
 0.29 per cent 
 
 0.51 per cent. 
 
 26.00 per cent 
 
 24.74 per cent. 
 
 71.20 per cent 
 
 71.10 per cent. 
 
 No separation 
 
 No separation. 
 
 13.70 per cent 
 
 11.80 per cent. 
 
 0.04 per cent 
 
 
 Preservative sold as Creolin. 
 
 Series I. 
 
 Series II. 
 
 Color 
 
 Specific gravity at 38° C 
 
 Distillates: * . 
 
 Below 170° C 
 
 From 170° C. to 205° C. 
 
 From 205° C. to 210° C. 
 
 From 210° C. to 235° C. 
 
 From 235° C. to 240° C. 
 
 From 240° C. to 270° C. 
 
 From 270° C. to 300° C. 
 
 Above 300° C 
 
 Loss 
 
 Total... 
 Naphthalene. 
 
 Water 
 
 Tar acids 
 
 Note 
 
 Light brown . 
 1.007 
 
 26. 66 per cent... 
 
 17. 39 per cent... 
 
 9. 27 per cent . . . 
 
 25. 92 per cent... 
 
 > 15. 98 per cent... 
 
 4. 24 per cent . . . 
 0. 54 per cent . . . 
 
 100. 00 per cent 
 
 35.19percent 
 
 20.00 per cent 
 
 19c. c 
 
 Sticks and other 
 foreign matter 
 present. 
 
 Light brown. 
 1.005. 
 
 96. 90 per cent. 
 0. 10 per cent. 
 
 0. 15 per cent. 
 
 0. 85 per cent. 
 2. 00 per cent. 
 
 100. 00 per cent. 
 
 None. 
 
 90 per cent. 
 
 1 c. c. 
 
 Sticks, sand, and 
 other foreign 
 matter present. 
 
APPENDIX. 
 
 49 
 
 DETAILED TABLES AND CURVES SHOWING RATE OF SEASONING 
 
 OF POLES.- 
 
 Table 27. — Rate of seasoning of southern white cedar poles at Wilmington, N. C. a 
 
 Duration 
 of sea- 
 soning. 
 
 Spring cut. 
 
 Summer cut. 
 
 Autumn cut. 
 
 Winter cut. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content, b 
 
 Weight 
 
 per cubic 
 
 loot. 
 
 Moisture 
 content, s 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content, b 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 6 
 
 Months. 
 
 1 
 2 
 3 
 4 
 5 
 6 
 7 
 8 
 9 
 
 10 
 11 
 12 
 13 
 14 
 15 
 16 
 17 
 
 Pounds. 
 34.8 
 27.7 
 26.3 
 25.9 
 25.7 
 25.6 
 25.5 
 25.4 
 25.4 
 25.3 
 25.0 
 
 Per cent 
 of dry- 
 weight. 
 68 
 34 
 27 
 25 
 24 
 24 
 23 
 23 
 23 
 22 
 21 
 
 Pounds. 
 36.6 
 28.5 
 .26.8 
 26.5 
 26.5 
 26.7 
 26.8 
 27.0 
 26.9 
 26.7 
 26.7 
 2G.6 
 26.5 
 26.4 
 26.2 
 26.2 
 26.1 
 26.0 
 
 Per cent 
 of dry 
 
 weight. 
 77 
 38 
 29 
 28 
 28 
 29 
 29 
 30 
 30 
 29 
 29 
 29 
 28 
 28 
 27 
 27 
 26 
 26 
 
 Pounds. 
 38.7 
 29.5 
 27.9 
 27.7 
 27.5 
 27.2 
 26.7 
 26.5 
 26.2 
 26.0 
 25.9 
 25.7 
 25.7 
 25.7 
 25.7 
 25.7 
 25.8 
 
 Per cent 
 of dry 
 
 weight. 
 87 
 43 
 35 
 34 
 33 
 31 
 29 
 28 
 27 
 26 
 25 
 24 
 24 
 24 
 24 
 24 
 25 
 
 Pounds. 
 
 38.9 
 29.9 
 28.3 
 26.7 
 26.5 
 26.0 
 25.7 
 25.6 
 25.6 
 25.6 
 25.5 
 25.5 
 25.5 
 25.5 
 
 Per cent 
 of dry 
 
 weight. 
 88 
 44 
 37 
 29 
 28 
 26 
 24 
 24 
 24 
 24 
 23 
 23 
 23 
 23 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 i 
 
 
 a Based on six hundred 25-foot and 30-foot poles. The average volume of 30-foot poles was 20.76 cubic 
 feet, and of 25-foot poles, 14.53 feet. 
 b Dry weight, according to Sharpless (Vol. IX, Tenth Census), is 20.7 pounds per cubic foot. 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 k 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 in 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 r 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 V* 
 
 
 
 
 ^-, 
 
 
 
 
 
 \^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 , 
 
 
 \ 
 
 
 
 
 
 
 
 
 13 /■*• /S /B 17 
 
 Fig. 7. — Rate of seasoning of southern white cedar poles, Wilmington, N. C. 
 
50 PRESEKVATIVE TREATMENT OP POLES. 
 
 Table 2S. — Rate of seasoning of chestnut poles at Pisgah, N. C. a 
 
 Duration 
 of sea- 
 soning. 
 
 Spring cut. 
 
 Summer cut. 
 
 Autumn cut. 
 
 Winter cut. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Months. 
 
 
 
 1 
 
 2 
 
 3 
 
 4 
 
 5 
 
 6 
 
 7 
 
 8 
 
 9 
 
 10 
 
 11 
 
 12 
 
 13 
 
 14 
 
 15 
 
 Pounds. 
 55.2 
 52.3 
 50.2 
 49.1 
 48.4 
 48.1 
 47.7 
 46.8 
 
 Per cent 
 of dry 
 
 weight. 
 97 
 86 
 79 
 75 
 72 
 71 
 70 
 67 
 
 Pounds. 
 53.5 
 50.6 
 48.3 
 47.0 
 46.3 
 46.0 
 45.8 
 45.7 
 45.7 
 45.3 
 44.8 
 43.8 
 43.5 
 43.3 
 43.3 
 43.2 
 
 Per cent 
 of dry 
 
 weight. 
 91 
 80 
 72 
 67 
 65 
 64 
 63 
 63 
 63 
 61 
 60 
 56 
 55 
 54 
 54. 
 54 
 
 Pounds. 
 54.7 
 51.7 
 50.3 
 49.9 
 49.6 
 49.0 
 48.8 
 48.3 
 47.3 
 46.4 
 45.8 
 45.5 
 44.8 
 
 Per cent 
 of dry 
 
 weight. 
 95 
 84 
 79 
 78 
 77 
 75 
 74 
 72 
 69 
 65 
 63 
 62 
 60 
 
 Pounds. 
 56.5 
 54.3 
 52.7 
 51.5 
 50.7 
 49.8 
 49.2 
 48.3 
 47.7 
 47.5 
 47.2 
 
 Per cent 
 of dry 
 weight. 
 101 
 93 
 88 
 83 
 81 
 77 
 75 
 72 
 70 
 69 
 68 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 a Based on six hundred 25-foot and 30-foot poles. The average volume of 30-foot poles was 21.12 cubic 
 feet, and of 25-foot poles 14.70 cubic feet. 
 
 Table 29. — Rate of seasoning of chestnut poles at Dover, N. J. a 
 
 Duration 
 of sea- 
 soning. 
 
 Spring cut. 
 
 Summer cut. 
 
 Autumn cut. 
 
 Winter cut. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Months. 
 
 1 
 2 
 3 
 4 
 5 
 6 
 7 
 8 
 9 
 10 
 11 
 12 
 13 
 14 
 
 Pounds. 
 50.8 
 49.0 
 47.5 
 46.5 
 46.0 
 45.5 
 45.1 
 44.5 
 
 Per cent 
 of dry 
 
 weight. 
 81 
 75 
 69 
 66 
 64 
 62 
 61 
 59 
 
 Pounds. 
 51.5 
 48.8 
 47.4 
 46.8 
 46.6 
 46.4 
 46.2 
 46.1 
 45.7 
 45.0 
 44.0 
 43.4 
 43.0 
 42.7 
 42.4 
 
 Per cent 
 of dry 
 weight. 
 83 
 74 
 69 
 67 
 66 
 65 
 65 
 64 
 63 
 . 60 
 57 
 55 
 53 
 52 
 51 
 
 Pounds. 
 50.8 
 48.4 
 47.2 
 47.0 
 46.8 
 46.6 
 46.2 
 45.5 
 44.7 
 43.9 
 43.2 
 42.8 
 42.5 
 42.2 
 
 Per cent 
 of dry 
 
 weight. 
 81 
 72 
 68 
 67 
 67 
 66 
 65 
 62 
 59 
 56 
 54 
 52 
 51 
 50 
 
 Pounds. 
 51.8 
 50.8 
 49.8 
 48.7 
 47.5 
 46.3 
 45.3 
 44.5 
 44.1 
 43.8 
 43.2 
 
 Per cent 
 of dry 
 
 weight. 
 85 
 81 
 77 
 73 
 69 
 65 
 61 
 59 
 57 
 56 
 54 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 a Based on four hundred 30-foot poles. Volume, 22 cubic feet. 
 
APPENDIX. 51 
 
 Table 30. — Rate of seasoning of chestnut poles at Thorndale, Pa. a 
 
 Duration 
 of sea- 
 soning. 
 
 Spring cut (vol- 
 ume, 20 cubic feet). 
 
 Summer cut (vol- 
 ume, 21 cubic feet). 
 
 Autumn cut (vol- 
 ume, 20 cubic feet). 
 
 Winter cut (vol- 
 ume, 20 cubic feet) 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Months. 
 
 
 
 1 
 
 2 
 
 3 
 
 4 
 
 5 
 
 6 
 
 7 
 
 8 
 
 9 
 10 
 11 
 12 
 13 
 14 
 15 
 17 
 19 
 20 
 21 
 23£ 
 
 Pounds. 
 53.0 
 50.1 
 47.9 
 46.4 
 45.4 
 44.8 
 44.4 
 43.9 
 43.6 
 43.6 
 43.6 
 42.4 
 43.0 
 42.5 
 42.3 
 42.1 
 41.8 
 41.5 
 41.3 
 41.0 
 40.7 
 
 Per cent 
 of dry 
 
 weight. 
 89 
 78 
 71 
 65 
 62 
 60 
 58 
 56 
 55 
 55 
 55 
 51 
 53 
 51 
 51 
 50 
 49 
 48 
 47 
 46 
 45 
 
 Pounds. 
 54.0 
 50.1 
 48.2 
 47.4 
 47.1 
 46.8 
 46.7 
 46.4 
 46.1 
 45.7 
 45.2 
 44.7 
 44.2 
 43.7 
 43.3 
 42.9 
 42.5 
 42.3 
 42.1 
 41.7 
 41.3 
 
 Per cent. 
 92 
 78 
 72 
 69 
 68 
 67 
 66 
 65 
 64 
 63 
 61 
 59 
 57 
 56 
 54 
 53 
 51 
 51 
 50 
 49 
 47 
 
 Pounds. 
 52.7 
 50.5 
 49.3 
 48.8 
 48.6 
 47.9 
 46.9 
 45.7 
 44.8 
 44.1 
 43.8 
 43.2 
 42.5 
 41.8 
 41.6 
 41.7 
 41.9 
 41.8 
 42.2 
 
 Per cent. 
 88 
 80 
 76 
 74 
 73 
 71 
 67 
 63 
 60 
 57 
 56 
 54 
 51 
 49 
 48 
 49 
 49 
 49 
 50 
 
 Pounds. 
 52.9 
 51.7 
 50.4 
 49.1 
 47.6 
 46.3 
 45.1 
 44.3 
 43.6 
 42.9 
 42.4 
 42.0 
 41.8 
 41.6 
 41.5 
 41.5 
 41.5 
 
 Per cent. 
 88 
 84 
 80 
 75 
 70 
 65 
 61 
 58 
 55 
 53 
 51 
 50 
 49 
 48 
 48 
 48 
 48 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Table 31. 
 
 a Based on six hundred 30-foot poles. 
 -Rate of seasoning of chestnut poles at Parkton, Md. a 
 
 Duration 
 of sea- 
 soning. 
 
 Fall cut. 
 
 Winter cut. 
 
 Spring cut. 
 
 Summer cut. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 AVeight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Months. 
 
 1 
 2 
 3 
 4 
 5 
 6 
 7 
 8 
 9 
 10 
 11 
 12 
 
 Pounds. 
 56.4 
 52.3 
 51.2 
 50.7 
 50.4 
 49.9 
 49.3 
 48.4 
 47.4 
 46.5 
 45.8 
 45.3 
 44.9 
 
 Per cent 
 of dry 
 
 weight. 
 85.4 
 72.0 
 68.4 
 66.9 
 65.8 
 64.3 
 62.2 
 59.2 
 56.0 
 53.0 
 50.8 
 
 Pounds. 
 56.4 
 53.9 
 52.5 
 51.3 
 50.1 
 48.8 
 47.7 
 46.7 
 46.0 
 45.4 
 
 Per cent. 
 85.6 
 77.4 
 72.6 
 68.7 
 64.8 
 60.6 
 56.8 
 53.7 
 51.2 
 49.3 
 
 Pounds. 
 55.6 
 51.8 
 49.9 
 48.6 
 47.6 
 46.7 
 46.1 
 
 Per cent. 
 83.0 
 70.5 
 64.3 
 60.0 
 56.5 
 53.7 
 51.7 
 
 Pounds. 
 56.1 
 51.0 
 
 48.8 
 47.9 
 
 47.4 
 
 Per cent. 
 84.4 
 67.9 
 60.6 
 57.5 
 55.9 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 49.1 
 
 47.8 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 a Based on five hundred and fifty 30-foot poles. Oven dry weight, determined on disks cut from the 
 poles, 30.4 pounds per cubic foot. Average volume, 20 cubic feet. 
 
52 
 
 PRESERVATIVE TREATMENT OE POLES. 
 
 58 
 
 vl 
 
 !« 
 
 kl 
 
 k 
 :*; 48 
 
 S 46 
 
 44 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 h, 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \^x 
 
 
 V 1 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 k 
 
 J; 
 
 ^ B4-.2. 
 
 5; 77.6 
 
 k 
 
 I sa 
 
 % 
 
 K 57.<? 
 
 O / a 3 4 5 6 7 a , 9 /O // /2 /3 
 
 OCT. A/OV. DEC. JAN. FEB. MAP. APR. MAY JUNE JULY AUG. SEPT. OCT. 
 T/ME SEASON /NG~MOA/T/-tS 
 
 44J 
 
 Fig. 8. — Rate of seasoning of chestnut poles, Parkton, Md. 
 Table 32. — Rate of seasoning of northern white cedar poles at Escanaba, Mich. « 
 
 Duration 
 of season- 
 ing. 
 
 Spring cut. 
 
 Summer cut. 
 
 Autumn cut. 
 
 Winter cut. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Months. 
 
 
 
 1 
 
 2 
 
 3 
 
 4 
 
 5 
 
 6 
 
 7 
 
 8 
 
 9 
 
 10 
 
 11 
 
 12 
 
 13 
 
 14 
 
 Pounds. 
 31.9 
 27.7 
 26.9 
 26.7 
 
 Per cent. 
 77 .4 
 53.8 
 49.7 
 48.4 
 
 Pounds. 
 32.7 
 29.1 
 27.3 
 26.8 
 
 Per cent. 
 81.7 
 61.4 
 51.9 
 49.1 
 
 Pounds. 
 32.2 
 
 Per cent. 
 79.0 
 
 Pounds. 
 34.2 
 
 Per cent. 
 90.0 
 
 
 
 
 
 
 
 33.6 
 27.5 
 25.6 
 24.8 
 24.2 
 
 86.4 
 53.0 
 42.3 
 37.5 
 34.3 
 
 
 
 
 
 
 
 31.9 
 25.7 
 24.0 
 23.2 
 22.9 
 
 77.2 
 43.0 
 33.2 
 29.0 
 27.2 
 
 
 
 
 
 
 
 
 
 
 
 26.6 
 25.3 
 24.4 
 23.9 
 23.5 
 
 48.0 
 40.5 
 35.7 
 32.9 
 30.7 
 
 
 
 
 
 
 
 
 
 26.0 
 24.5 
 24.1 
 23.8 
 
 44.2 
 36.0 
 33.7 
 32.3 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 1 
 
 
 a Based on 450 poles. Ovendry weight=18 pounds per cubic foot. Average volume, 17.62 cubic feet. 
 
 winter co?. 
 
 ki 26 
 
 
 
 
 
 
 
 
 AU 
 
 TUMfi. 
 
 ' CU7 
 
 
 "v 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 > 
 
 
 
 
 
 
 V 
 
 * 
 
 
 
 c 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 N^5 
 
 
 
 
 leu 
 
 r 
 
 
 
 
 
 A 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ~—< 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 L 
 
 ■ — 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 .APR. MAY JUNE JUL Y AUS. SEPT. OCT. NOV. DEC. JAN. FEB. MAP. APR. MAY JUNE JULY 
 TIME SEASONING -MONTHS 
 
 Fig. 9. — Rate of seasoning of northern white cedar poles, Escanaba, Mich. 
 
APPENDIX. 53 
 
 Table 33. — Rate of seasoning of western red cedar poles at Los Angeles, Cal.a 
 
 Duration 
 of season- 
 ing. 
 
 Summer cut. 
 
 Fall cut. 
 
 Winter cut. 
 
 Spring cut. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. . 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Months. 
 
 1 
 2 
 3 
 4 
 5 
 6 
 7 
 8 
 9 
 10 
 11 
 12 
 13 
 
 Pounds. 
 6 42.4 
 
 Per cent 
 of dry 
 
 weight. 
 133.0 
 
 Pounds. 
 6 42.4 
 
 Per cent 
 of dry 
 
 weight. 
 133.0 
 
 Pounds. 
 6 42.4 
 
 Per cent 
 
 of dry 
 
 weight. 
 
 133.0 
 
 Pounds. 
 6 42.4 
 
 Per cent 
 
 of dry 
 
 weight. 
 
 133.0 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 C38.12 
 33.0 
 31.0 
 29.3 
 28.0 
 
 109.5 
 81.3 
 70.3 
 61.0 
 53.8 
 
 
 
 
 
 C36.12 
 
 28.25 
 26.30 
 25.30 
 
 98.5 
 55.2 
 44.5 
 39.0 
 
 
 
 
 
 c32.5 
 31.1 
 30.0 
 2S.5 
 26.5 
 25.0 
 23.5 
 23.46 
 
 78.6 
 70.9 
 64.8 
 56.6 
 45.6 
 37.4 
 29.1 
 28.9 
 
 
 
 C33.0 
 29.0 
 26.5 
 25.5 
 
 81.3 
 59.3 
 45.6 
 40.1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 o Based on four hundred 40-foot poles. The average volume of 300 poles was 27.34 cubic feet. Oven dry 
 weight determined by sections cut from 12 poles, 18.2 pounds per cubic foot. 
 b Green weight based on weights of 25 summer cut poles taken immediately after cutting, 
 c Weight on arrival at Los Angeles, Cal., from three to seven months after cutting. 
 
 ^■34 
 
 i 
 
 28 
 
 
 
 
 
 
 
 ■s 
 
 
 
 
 
 
 
 
 
 
 
 N 
 
 
 
 %K 
 
 * N S 
 
 
 N 
 
 <H. 
 
 
 
 X 
 
 
 
 
 
 
 
 
 
 N. 
 
 
 
 N. 
 
 ., 
 
 ^ 
 
 ?■ 
 
 
 
 S 
 
 
 
 
 
 
 
 
 N 
 
 N 
 
 
 
 
 \ 
 
 V 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 b 
 
 
 
 s 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 ^> 
 
 s°<-- 
 
 
 
 \ \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Vs. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 i 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 O I Z 3 4- 5 6 7 O 9 /O // A? /3 At /S /S 17 
 
 juir At/6, sept, ocr. Nov. oec. jan. fee. map. app. may junejuly aug. sept. oct. now. 
 
 T/ME SEASONING -MONTHS 
 
 Fig. 10. — Rate of seasoning western red cedar poles, Los Angeles, Cal. 
 
54 
 
 PRESERVATIVE TREATMENT OF POLES. 
 
 Table 34. — Rate of seasoning of western yellow pine -poles at North Fork, Madera County, 
 
 Cal.a 
 
 Duration 
 of season- 
 ing. 
 
 Autumn cut. 
 
 Winter cut. 
 
 Spring cut. 
 
 Summer cut. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Weight 
 
 per cubic 
 
 foot. 
 
 Moisture 
 content. 
 
 Months. 
 
 1 
 2 
 3 
 4 
 5 
 6 
 7 
 8 
 9 
 10 
 
 Pounds. 
 64.1 
 54.0 
 51.3 
 52.6 
 54.1 
 50.4 
 46.0 
 41.7 
 37.6 
 33.7 
 30.3 
 
 Per cent 
 
 of dry 
 
 weight. 
 
 144.7 
 
 106.1 
 
 95.8 
 
 100.8 
 
 106.5 
 
 92.4 
 
 75.6 
 
 59.2 
 
 43.5 
 
 28.6 
 
 15.6 
 
 Pounds. 
 66.6 
 62.6 
 56.2 
 47.7 
 40.4 
 36.0 
 32.8 
 
 Per cent 
 of dry 
 weight. 
 154.2 
 138.9 
 114.5 
 82.1 
 54.2 
 37.4 
 25.2 
 
 Pounds. 
 65.2 
 51.5 
 44.4 
 38.8 
 36.2 
 32.6 
 
 Per cent 
 of dry 
 weight. 
 148.9 
 96.6 
 68.5 
 51.9 
 38.2 
 24.4 
 
 Pounds. 
 64.8 
 40.3 
 33.8 
 31.8 
 
 Per cent 
 of dry 
 weight. 
 147.3 
 53.8 
 29.0 
 21.4 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 a Based on four hundred 40-foot poles. Oven dry weight, 26.2 pounds per cubic foot. Average volume 
 8.1 cubic feet. 
 
 
APPENDIX. 
 
 55 
 
 66 
 
 
 
 
 V 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 62 
 
 60 
 SB 
 56 
 E4 
 
 rise 
 I so 
 
 *< 48 
 tj 
 
 §3 
 
 5) 46 
 <J 
 
 n' 44 
 
 V* 
 
 
 
 \ 
 
 k 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ' 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ A 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ft 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ ^> 
 
 
 1 0, 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 f> 
 
 1 r 
 
 i 
 
 
 
 
 
 
 
 
 
 
 
 
 
 i 
 
 
 
 \ 
 
 40 
 38 
 36 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 3Z 
 
 30 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 /S/.9 
 Z44-.3 
 /36.B 
 
 /aao' 
 
 /E/.4- 
 
 //3.y 
 
 /OS./ 
 98. S 
 9D.8 
 83.£ 
 75.6 
 B7.9 
 60.3 
 
 sa.7 
 
 ■45.0 
 37.4- 
 
 29.8 
 
 a a./ 
 
 /•4.S 
 
 O / B 3 4- 5 6 7 8 9 /O // /2 /3 
 
 OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUB. SEPT. OCT. 
 T/ME SEASON/NS-MONTHS 
 
 Fig. 11.— Rate of seasoning of western yellow pine poles, Madera County, Cal. 
 
 o