UNIVERSITY OF CALIFORNIA PUBLICATIONS COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY, CALIFORNIA The Relative Cost of Making Logs from Small and Large Timber BY DONALD BRUCE BULLETIN 339 January, 1922 UNIVERSITY OF CALIFORNIA PRESS BERKELEY, CALIFORNIA 1922 David P. Barrows, President of the University. EXPERIMENT STATION STAFF HEADS OP DIVISIONS Thomas Forsyth Hunt, Dean. Edward J. Wickson, Horticulture (Emeritus). , Director of Resident Instruction. C. M. Haring, Veterinary Science, Director of Agricultural Experiment Station. B. H. Crocheron, Director of Agricultural Extension. H. J. Webber, Citriculture, Director of Citrus Experiment Station. Hubert E. Van Norman, Dairy Management. William A. Setchell, Botany. Myer E. Jaffa, Nutrition. Ralph E. Smith, Plant Pathology. John W. Gilmore, Agronomy. Charles F. Shaw, Soil Technology. John W. Gregg, Landscape Gardening and Floriculture. Frederic T. Bioletti, Viticulture and Fruit Products. Warren T. Clarke, Agricultural Extension. Ernest B. Babcock, Genetics. Gordon H. True, Animal Husbandry. James T. Barrett, Plant Pathology. Walter Mulford, Forestry. Fritz W. Woll, Animal Nutrition. W. P. Kelley, Agricultural Chemistry. H. J. Quayle, Entomology. Elwood Mead, Rural Institutions. H. S. Reed, Plant Physiology. L. D. Batchelor, Orchard Management. J. C. Whitten, Pomology. *Frank Adams, Irrigation Investigations. C. L. Roadhouse, Dairy Industry. R. L. Adams, Farm Management. W. B. Herms, Entomology and Parasitology. F. L. Griffin, Agricultural Education. John E. Dougherty, Poultry Husbandry. D. R. Hoagland, Plant Nutrition. G. H. Hart, Veterinary Science. L. J. Fletcher, Agricultural Engineering. Edwin C. Voorhies, Assistant to the Dean. division of forestry Walter Mulford Kmanuel Fritz Donald Bruce Arthur W. Sampson Woodbridge Metcalf Francis X. Schumacher * In cooperation with office of Public Roads and Rural Engineering, U. S. Department of Agriculture. THE RELATIVE COST OF MAKING LOGS FROM SMALL AND LARGE TIMBER By DONALD BEUCE The stop watch has for many years been used by efficiency engineers in analyzing industrial operations along many lines. Few time studies of logging, however, have ever been made and of less have the results been made available through publication. The study which is to be partly described in this bulletin was made on the logging operations of three representative lumber companies of the Sierra Nevada, each operating with modern machinery efficiently handled. One of the three is located in conditions typical of the east side of the Sierra, one in those of the west side, while the third is intermediate. Each of the three companies cooperated cordially and extended every facility for work. Mr. Swift Berry, Logging Engineer of the U. S. Forest Service at the time of the study, also gave valuable assistance in initiating it. The study was not designed to prove or disprove any theory, nor even to ascertain any specific facts. It was intended rather as a general investigation of the factors affecting the cost of logging. Yet while these factors were many, the one outstanding result of the w T ork was a proof of the excessive cost of logging small timber as compared to large, when methods and machinery adapted to the latter are used. The present bulletin restricts itself entirely to log making, i.e., falling, limbing, marking and bucking. The following pages will show that it costs three times as much per M. B. M. to make logs from 18-inch as from 48-inch trees, and that below that diameter the costs undoubtedly rise rapidly with each further decrease in size. Table I and figure I summarize the results obtained. In the figure it will be noted that not only the total cost but that of three out of four of the individual operations fall rapidly as diameters increase up to about 40 inches. Limbing alone is an exception and its relative im- portance is small. Bucking remains practically constant for the largest sizes although its decrease for small sizes is most rapid of all. No figures for trees under 18 inches in diameter were available, but the trend of the curves is convincing evidence that even higher costs would be encountered for these smaller sizes. 318 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION TABLE I Effect of Tree Diameter on Cost of Log Making Diameter Cost per M. B. M. breast t A v high Falling Marking Limbing Bucking Total 18 $0.77 $0.18 $0.08 $1.02 $2.05 20 .67 .17 .08 .84 1.76 22 .60 .17 .09 .68 - 1.54 24 .55 .16 .10 .58 1.39 26 .50 .15 .12 .50 1.27 28 .45 .13 .13 .44 1.15 30 .41 .12 .14 .40 1.07 32 .37 .10 .14 .38 .99 34 .34 .09 .15 .36 .94 36 .30 .08 .15 .35 .88 38 .27 .07 .14 .34 .82 40 .25 .06 .14 .33 .78 42 .23 .05 .13 .33 .74 44 .21 .04 .12 .33 .70 46 .20 .04 .11 .33 .68 48 .19 .03 .11 .33 .66 "Wage Scale Used — Per day Fallers - $5.00 Markers 4.75 Limbers 4.25 Buckers, steam saw, head 5.00 Buckers, steam saw, second 4.25 Buckers, hand 4.50 * *200 180 M Lim him ? a — a Mat Fa// k/nc t'ng ) c — I? c /■SO B(/c Ton kinQ e — d e *^ 120 * 100 d < 3 .80 60 40 e cf JO — £ a ki— i 10 44- 46 48 20 ZZ 24 26 23 30 32 J4 36 36 40 42 D/'amefer />r€ast~ hiqh — //?ohes Fig. 1. — Effect of tree diameter on cost per M. B. M. of log making. Bulletin 339] RELATIVE COST OF MAKING LOGS 319 During periods of rapidly changing wage scales, cost figures in dollars and cents are apt to be misleading. On this account costs were reckoned in minutes of labor throughout this study except in the fore- going table where time was translated into money at the wage scale indicated beneath. All wages are for a nominal 10-hour day, but the value of a minute of time was calculated on the basis of the actual number of minutes worked per day on the operations studied, a some- what lower figure. The data upon which the conclusions were based will now be described, together with the method of reaching them. Falling, mark- ing, limbing and bucking will each be treated separately. FALLING The study included stop-watch observations on the falling of 113 trees, having a scale of 177 M. B. M., gross, and 151 M. B. M., net. Measurements of diameter and volume of each tree and the exact time for each of the following items was recorded : "Walking'' (from tree to tree), "Swamping," "planning" (look- ing over ground, deciding on direction of fall, etc.), "undercutting with saw," "undercutting with axe," "barking," "preparing to saw' : (including preliminary oiling of saw), "sawing," "wedging,'' "tool fitting," "gathering tools'' (preparatory to moving to next tree to be failed), "whistle" (interval between the close of work and the whistle which marked the end of day for yarders), "delays" (each sort of delay being separately recorded). Table II is a summary of the results obtained and shows not only the total time spent on each of the above listed items, but also the average time for each item per tree and the per cent of the total time. The times recorded are man-minutes and not crew-minutes. Of the items timed it is obvious that some will be independent of tree diameter but will in the long run (though varying widely in indi- vidual cases) tend to approach a constant average per tree. "Walk- ing" and "gathering tools" are clearly of this nature, and it is there- fore reasonable to charge to each tree the average for these two items given in Table II, totaling 1.69 minutes per tree. This figure is of course independent of species also. A large number of other items will obviously vary with the diameter of the tree. Some, such as "sawing," "wedging," etc., were unques- tionably of this class while in the case of others, such as ' ' swamping, ' an examination of the data was necessary to permit a decision. The items finally included in this class are as follows : 320 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Planning, ' ''undercutting,' 1 "barking,' 1 "preparing to saw," sawing," "wedging," certain "delays," such as "oiling," "setting spring boards, ' ' etc. TABLE II Summary of Time Bequired to Fall 113 Trees Average Time Minutes Per cent of Operation per Tree, Time Walking 0.96 1.91 Swamping 1.48 2.96 Planning 2.66 5.33 Undercutting — saw 3.02 6.06 Undercutting — axe 7.53 15.13 Barking 3.93 7.91 Preparing to saw 2.16 4.34 Sawing 8.42 16.90 Wedging 2.33 4.68 Tool Fitting 0.50 1.01 Resting 12.97 26.05 Gathering Tools 0.73 1.45 Whistle 0.51 1.02 Delays 2.60 5.25 TOTALS 49.80 100.00 The 113 trees observed were about half white fir, and half western yellow pine. As a preliminary analysis showed that the differences between the times for trees of the same diameter for the two species was almost imperceptible, the two were averaged together at first, leav- ing until later the more precise determination of the effect of species. Table III shows the actual averages obtained for different size classes and the most probable true values for the same as adjusted graphically. TABLE III Influence of Diameter on Time of All Falling Items Directly Affected Thereby Diameter Class. Inches Average time for items varying with diameter. Minutes per tree Same adjusted graphically. Minutes per tree Basis Number Trees 20-24 23.4 22.5 16 25-29 24.9 26.8 32 30-34 33.5 31.7 27 35-39 36.9 37.3 23 40-44 44.8 45.8 9 45-49 59.7 58.4 5 112* The effect of species was now studied, and it was found that the \v Same, Curved 2 1 2.9 3.1 .6 3.7 5.9 3 6 4.5 4.6 .6 5.2 8.4 4 22 6.2 6.1 .6 6.7 10.8 5 10 7.0 7.6 .6 8.2 13.3 6 5 1 0.2 9.2 .6 9.8 15.7 A recalculation now showed that previous limbing reduced the "marking" time by 10 per cent. While to express marking time in terms of height is the most logical procedure it is impossible to correlate the figures thus compiled with Bulletin 339] RELATIVE COST OF MAKING LOGS 323 those already calculated translate them into terms be done. for falling. It is therefore desirable to of diameter ; Table VII shows how this may TABLE VII Time Cost of Marking as Affected by Diameter Diameter Breast High Inches Average Merchantable Height Logs (16 ft.) Time per Tree — Minutes Average Gross Volume per Tree M. B. M. Time per M. B. M Gross Scale Minutes 18 2.8 7.9 .40 19.7 20 3.4 9.3 .50 18.6 22 3.9 10.6 .59 18.0 24 4.3 11.6 .68 17.1 26 4.7 12.6 .79 15.9 28 4.9 13.0 .93 14.0 30 5.1 13.5 1.11 12.2 32 5.3 14.0 1.31 10.7 34 5.5 , 14.5 1.54 9.4 36 5.7 15.0 1.86 8.1 38 5.9 15.5 2.21 7.0 40 6.1 L5.9 2.63 6.0 42 6.3 16.4 3.14 5.2 44 6.5 16.9 3.78 4.5 46 6.7 17.5 4.54 3.9 48 7.0 18.2 5.10 3.6 Column 2 of this table was derived from a curve showing the mer- chantable height of trees of various diameters, the basis for which was all the trees measured on the operation located on the east side of the Sierra, both in connection with falling, marking and limbing. Column 3 is derived from the final column of Table VI, the values being inter- polated and exterpolated to correspond to the exact heights given in Column 2. Column 4 is obtained from the volume table already de- scribed on page 321. Column 5 is column 3 divided by column 4. This final column was the basis for column 3 of Table I, allowance first being made for cull, amounting to 13.2%, and the modified times then being multiplied by the cost per minute based on the wage stated. It will readily be seen that Table VII should not be expected to apply accurately to any operation other than that from which the data were obtained. The relation between height and diameter, that between volume and diameter, and the cull percentage might well all be different in another region. Furthermore, the high percentage of time used for resting (Table V), indicates that the marker was not kept very busy by the organization studied. All these factors might modify the actual costs under different circumstances, but should not affect materially the relation between the costs for large trees and small. 324 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION LIMBING Observations were made on the limbing done by three different workmen of 125 trees, having a scale of 210 M. B. M. gross, and 180 M. B. M. net. Table VIII summarizes the results. TABLE VIII Summary of Time Eequired to Limb 125 Trees Average Time Per cent per Tree — of Total Operation Minutes Time Waiting for fallers 8.17 33.58 Walking 89 3.65 Preparing to work 06 .23 Chopping 11.42 46.97 Eesting 3.58 14.72 Miscellaneous 21 .85 Totals 24.33 100.00 The most striking figures in this summary are the percentages of time spent in waiting for fallers and in resting, which together amount to 48 per cent of the total. It is obvious that the men were not kept very busy and that the costs calculated on the basis of their work may prove abnormally high. As in the case of marking however, the relative costs for different sizes of trees should be reliable. Using the same grouping as in the previous cases it will readily be scon that ''chopping' 1 should vary with the diameter of the tree, 'walking" and "preparing to work" should be treated as a constant time per tree, while the remaining items may be prorated. Table IX shows the computations by which the time cost per M. B. M. are worked out. Column A is obtained by graphically averaging the actual times spent in chopping on trees of different diameters, using only the west- ern yellow pine, 71 in number. Column B is taken directly from Table VIII. The next column adds these two items together, while the fifth prorates the remaining items. Column 6 is taken from the volume table already described, and column 7 is derived by dividing column 5 by column 6. From this final column, column 4 of Table I was derived by allow- ing for cull (7.5% in the case of the yellow pine limbed) and multiply- ing by the cost of a minute's time. Bulletin 339] RELATIVE COST OF MAKING LOGS 325 TABLE IX Time Cost of Limbing as Affected by Tree Diameter Time per Tree, Minutes Diameter Breast High- Inches t A Chopping B Walking and Preparing A + B Total (A+B multi- plied by 1.966 to prorate other items) Average gross volume ~ per Tree M. B. M. Time per M. B. M. Gross Scale Minutes 18 .9 .9 1.8 3.5 .40 8.7 20 1.4 .9 2.3 4.5 .50 9.0 22 2.2 .9 3.1 6.1 .59 10.3 24 3.3 .9 4.2 8.3 .68 12.2 26 4.6 .9 5.6 11.0 .79 13.9 28 6.4 .9 7.3 14.3 .93 15.4 30 8.2 .9 9.1 17.9 1.11 16.1 32 10.3 .9 11.2 22.0 1.31 16.8 34 12.7 .9 13.6 26.7 1.54 17.3 36 15.2 .9 16.1 31.6 1.86 17.0 38 17.8 .9 18.7 36.8 2.21 16.7 40 20.6 .9 21.5 42.3 2.63 16.1 42 23.5 .9 24.4 48.0 3.14 15.3 44 26.6 .9 27.5 54.0 3.78 14.3 46 29.7 .9 30.6 60.2 4.54 13.2 48 33.0 .9 33.9 66.6 5.10 13.1 The fact that medium-size trees are more expensive to limb than either very small or very large ones can probably be explained by the fact that in the former the limbs, while numerous, are light and easily removed while the latter have their large limbs concentrated at the top above the merchantable portion of the trunk. BUCKING This is the most important of the operations of log making from the standpoint of cost, and was therefore studied more exhaustively than the others. In both the camps where observations were made, trees were bucked into long lengths in the woods by hand, yarded in this form, and then further bucked into short car lengths by steam saw in a chute at the landing. Studies were therefore made of both hand bucking and steam-saw bucking. HAND BUCKING Times were recorded for 346 cuts, made by five different laborers, and with a scale of 432 M. B. M., gross, and 416 M. B. M. net. Table X summarizes the results. 326 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION TABLE X Summary of Time Bequired to Buck 346 Cuts by Hand Average Time per Tree — Per cent of Operation Minutes Total Time Walking 99 3.42 Preparing to work 35 1.21 Swamping ,. ' 3.60 12.40 Chopping 63 2.17 Sawing 10.36 35.68 Wedging 1.D1 3.49 ■ Oiling Saw 83 2.85 Gathering tools 53 1.82 Besting 5.11 17.60 Filling oil bottle 09 .30 Blocking up 11 .39 Changing ax .04 .13 Getting wedges 27 .94 Changing sides 06 .22 Preparing to undersaw 12 .42 Adjusting undercutter 13 .43 Looking over situation 27 .99 Beleasing saw 02 .07 Tool sharpening, fitting 14 .48 Looking for mark 03 .12 Walking in and out 3.54 12.17 Non-classifiable 78 2.70 Totals 29.01 100.00 As an inspection of the data revealed a marked variation between the different buekers a preliminary study was made to determine their relative efficiency, etc., the resulting figures being as follows: .88; 1.16; 1.20; .86; .88; (1.00 being the average of the five). These effi- ciency factors apply to the time of items varying with diameter only and is independent of the amount of time spent resting. They were used to bring the times of the individual workmen to a common standard before attempting to determine the influence of diameter. The investigation then followed the lines already described. The items varying with diameter were in this case, "sawing," " chopping, ' : " wedging, " and "oiling"; the effect of diameter on these items, after graphic, averaging, is given in the first two columns of Table XT. "Walking," "preparing to work," "gathering tools," and "swamp- ing," which may obviously be treated as constant per cut, are found in Table X to total 5.5 minutes, and this amount is added to give column B of Table XT. The remaining items include 36.96% of the total time, and this amount is prorated in column C. The final column I), is obtained by dividing each value of column C by the scale of a 16- foot log of the corresponding diameter (Scribner, Dec. C log rule). The use of 16-foot logs in computing this last column is to give results comparable to those which would have been obtained had all Bulletin 339] RELATIVE COST OF MAKING LOGS 327 the bucking been done by hand in the woods. It might at first appear that a serious inaccuracy is involved therein, on account of the fact that the workmen would have less walking to do between cuts in buck- ing short lengths than they had in the operations studied. It will be observed, however, in Table X, that "walking" only occupies 3.42% of the total time and as much of this is between trees, instead of be- tween cuts, the possible savings therein must be relatively insignificant. TABLE XI Time Cost of Hand Bucking as Affected by Diameter of Cut Time per Tree — Minutes Diameter of Cut Inside Bark — Inches 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 The final figures are moreover slightly artificial because of the use of the standard 16-foot log length. If they are to be compared with those of some other operation in which the logs average for example, 18 feet long, they should be reduced by multiplying them by 16/18. This will, of course, not disturb the relative costs of the different sizes. Cost figures for long-length bucking are usually based on the entire scale of the long logs manufactured, rather than on the 16-foot section below each cut. It is useless to compute such figures, however, for logs of various top diameters, since the scale of a log of any given diameter is not a constant, but varies with its length. Such figures may, on the other hand, properly be based on tree diameter, and this has been done in Table XV, hereafter to be presented. A Sawing, chopping, wedging and oiling B Same, plus walk- ing, gathering tools, etc. (A + 5.5) C Same, corrected to prorate de- lays, etc. (BX1.586) D Time per M. B. M Gross Scale, 16 foot logs, Minutes 2.2 7.7 12.2 407.0 2.9 8.4 13.3 221.7 3.7 9.2 14.6 182.4 4.5 10.0 15.9 144.5 5.2 10.7 17.0 106.2 6.1 11.6 18.4 87.6 7.2 12.7 20.1 71.8 8.3 13.8 21.9 .66.4 10.0 15.5 24.6 61.5 11.8 17.3 27.4 54.8 13.8 19.3 30.6 52.7 16.0 21.5 34.1 51.6 18.5 24.0 38.1 51.5 21.1 26.6 42.2 52.7 23.5 29.0 46.0 50.0 26.3 31.8 50.4 47.1 28.9 34.4 54.6 45.5 32.0 37.5 59.5 44.4 34.5 40.0 63.4 42.8 37.4 42.9 68.0 42.8 40.3 45.8 72.6 42.0 43.3 48.8 77.4 41.3 46.4 51.9 82.3 40.8 49.7 55.2 87.5 40.1 52.8 58.3 92.5 39.4 328 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION STEAM-SAW BUCKING Studies were made of two steam saws, but on analysis, it was found that one of the saws was so inefficient that the values obtained there- from were irregular and confusing, and of little value. The summary of the study of the saw which was functioning properly is given in Table XII, 233 cuts having been observed, with a scale of 173 M. B. M., gross. TABLE XII Summary of Time Eequired to Buck 233 Cuts by Steam Saw Average Time Per cent of Operation per Cut — Minutes Total Time Waiting for swing donkey 3.02 61.47 Spotting 18 3.60 Eeleasing choker 24 4.96 Setting dogs 19 3.87 Sawing 94 19.19 Releasing saw 21 4.21 Looking for mark 01 .17 Landing delay 06 1.31 Lining up saw 01 .29 Engine trouble 01 .12 Saw trouble 01 .25 Chute trouble 01 .27 Out of chute 01 .15 Stopping to wedge 01 .06 Miscellaneous 01 .08 Totals 4.92 100.00 Of these cuts 190 were in western yellow pine and these only were used in studying the effect of diameter on time. The time items af- fected by diameter were in this case "spotting," "setting dogs," : 'sawing," "releasing saw,'' "looking for mark,' "lining up saw, ' : and "stopping to wedge." The remaining items, amounting to 68.61% of the total, are all of the sort which should be prorated. Table XIII shows the resulting figures. The values in column B have been graphically averaged, and those of the final column have been slightly adjusted to eliminate an irregularity which resulted from the irregular progressions of the Scribner rule. Bulletin 339] RELATIVE COST OF MAKING LOGS 329 TABLE XIII Time Cost of Steam Saw Bucking as Affected by Diameter of Cut A B C D Diameter of Cut Inside Bark — Inches Time of Items Dependent on Diameter — Minutes per cut Time, all items BX3.14 Minutes per cut Time per M. B. M. Gross Scale, 16 foot Logs — Minutes 12 .8 2.4 .30 13 .8 2.5 .26 14 .8 2.5 .23 15 .8 2.6 .20 16 .9 2.7 .17 17 .9 2.8 . .16 18 .9 3.0 .14 19 1.0 3.1 .13 20 1.0 3.3 .12 21 1.1 3.6 .12 22 1.2 3.8 .11 23 1.3 4.0 .11 24 1.4 4.3 .11 25 1.5 4.6 .10 26 1.6 4.9 .10 27 1.7 5.3 .10 28 1.8 5.6 .09 29 1.9 5.9 .09 30 2.0 6.3 .09 31 2.1 6.7 .09 32 2.2 7.1 .09 33 2.4 7.6 .10 34 2.5 8.1 .10 35 2.7 8.6 .10 36 2.9 9.3 .11 37 3.1 9.9 .11 38 3.3 10.6 .12 Bucking of Trees by Combination of Two Methods The foregoing tables show the time cost of bucking logs of various diameters, and it now remains to investigate the bucking cost for trees of various diameters. This will depend in part on the height and form of the trees of each diameter class, and in part on the relative amounts of bucking done by hand and left to the steam saw. It is therefore impossible to arrive at figures which are universally applicable, but it is possible to work out conclusions reasonably accurate for the log- ging operation studied. 330 UNIVERSITY OF CALIFORNIA— EXPERIMENT STATION TABLE XIV Time Cost of Bucking, Part in Woods by Hand, and Part on Landing by Steam Saw, as Affected by Tree Diameter Diameter Average Breast High Height — Inches Logs Diameter Inside Bark — Inches, of Logs Bucked in A Gross Scale Scribner D. C. Feet B. M. Time— -Minutes A Time per M. B. M. gross scale — Minutes A r Woods Chute r Woods Chute Woods ' Chute 18 3 8 12 32 79 12.2 2.4 14 114 2.6 . 225 12.2 5.0 54.2 22.2 20 3 9 13 -15 40 97 142 12.7 2.5 2.6 279 12.7 5.1 45.5 18.3 22 4 9 13 15 17 40 97 142 185 12.7 2.5 26 2.9 464 12.7 8.0 27.4 17.2 24 4 9 14 16 18 40 114 159 213 12.7 2.6 2.7 3.0 526 12.7 8.3 24.1 15.8 26 4 9 14 18 20 40 114 213 280 12.7 2.5 3.0 3.3 647 12.7 8.8 19.6 13.6 28 5 9 15 18 20 22 40 142 213 280 334 12.7 2.6 3.0 3.3 3.8 . 1009 12.7 12.7 12.6 12.6 ' 30 5 9 16 19 22 23 40 159 240 334 377 12.7 2.7 3.2 3.8 4.0 1150 12.7 13.7 11.0 11.9 32 5 10 17 20 23 25 50 185 280 377 459 13.3 2.8 3.3 4.0 4.6 1351 13.3 14.7 9.8 10.9 34 6 9 23 16 21. 26 27 40 159 304 377 500 548 12.7 23.2 2.7 3.6 4.9 5.3 1928 35.9 16.5 18.6 8.6 Bulletin 339] RELATIVE COST OF MAKING LOGS 331 TABLE XIV— (Concluded) Diameter Average Breast High Height — Inches Logs Diameter Inside Bark — Inches, of Logs Bucked in " A Gross Scale Scribner D. C. Feet B. Id Time— -Minutes A Time per M. B. M. gross scale — Minutes A "Woods Chute r [. Woods Chute Woods Chute 36 6 9 25 17 22 27 29 40 185 334 459 548 609 12.7 26.0 2.8 3.8 5.3 5.9 2175 38.7 17.8 17.8 8.2 38 6 10 26 18 23 28 31 50 213 377 500 582 710 13.3 27.4 3.0 4.0 5.6 6.7 2432 40.7 19.3 16.7 7.0 40 6 10 27 19 24 30 32 50 240 404 548 657 736 13.3 28.9 3.1 4.3 6.3 7.1 2635 42.2 20.8 16 7.9 42 6 10 29 20 25 31 34 50 280 459 609 710 800 13.3 32.3 3.3 4.6 6.7 8.1 2908 45.6 22.7 15.7 7.8 44 7 10 34 19 25 29 32 36 50 240 459 609 736 800 923 13.3 42.2 3.1 4.6 5.9 7.1 9.3 3817 55.5 30.0 14.5 7.9 46 7 11 20 65 280 13.9 3.3 26 500 4.9 30 33 657 784 34.1 7.6 36 38 923 1068 46.0 10.6 4277 94.0 26.4 22.0 6.2 48 7 11 31 37 21 27 35 39 65 304 548 710 876 1029 1120 13.9 36.1 48.2 3.6 5.3 8.6 11.4 4652 98.2 28.9 21.1 6.2 332 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Table XIV gives the computations involved. Column 1 and 2 are derived from the height-diameter study already described (page 323). The values of columns 3 and 4 are taken from the standard taper table for western yellow pine of the U. S. Forest Service. This table is not exactly applicable to the type of timber which was studied, but since any differences will tend to modify both the diameters cut and the volumes produced in the same direction, it can be used here with- out serious error. A careful study of the data showed that it was customary for the buckers in the woods to saw a single top cut for trees up to and including 32 inches in diameter, to divide into two logs trees from 34 to 44 inches, inclusive, and to divide into 3 logs all larger trees. (This represents the average practice only and was not followed at all rigidly.) The values were assigned to Column 3 or 4 to agree with this procedure. Column 5 gives the scale of the logs and of the trees. Columns 6 and 7 give the time required to make the various cuts, their values being taken from column D of Table XI, and column D of Table XIII, respectively. The final columns, 8 and 9, are columns 6 and 7, respectively, divided by column 5, and with the decimal point shifted to express the results in terms of thousands of feet B. M. From the final columns, column 5 of the original Table I (p. 318) was derived by allowing for cull, multiplying by the proper cost of a minute's time, and graphically adjusting slight irregularities. GENERAL CONSIDERATIONS AND CONCLUSIONS The foregoing tables have been presented at length not only to support the conclusion stated on page 317, but also because it is felt that there is much information therein which may prove of value to lumbermen who are studying the details of their operations with a view to increased efficiency. Physical conditions vary widely between the several lumbering regions of the state and even between different logging units of a single operation, and it is therefore futile to hope for figures of exact applicability everywhere. It has been found, however, that analyzed figures on details will often apply where totals will not. For example, the time required to fall a tree of a given diameter was substantially the same on the different operations studied, but the cost per M. B. M. varied widely on account of the variation in height and volume between trees of the same diameter; that is, Table XIV, would not apply well to regions where the timber is very tall, but it would be relatively easy to construct from the detailed figures pre- viously presented a similar table which would be approximately correct for any known conditions. Bulletin 339] RELATIVE COST OF MAKING LOGS 333 Throughout this study unessential refinements have been avoided, and the highest degree of simplicity consistent with reliable results has been sought. In some instances slight inaccuracies have been accepted as preferable to complexity, but only where it could be clearly seen that they were of negligible importance. It is of interest to consider the probable causes which underlie the high cost per M. B. M. of manufacturing small logs. These are three in number : 1. The Scribner log rule (as well as the Spaulding) is ultra-con- servative in the values assigned to small logs ; whereas an overrun of 6% is to be expected for 48-inch trees, as much as 24% should be obtained from 18-inch trees. Were the results of Table I expressed in terms of lumber tally instead of log scale, therefore, the cost of log making from the smallest size tree would be only 2% times instead of three times that from the largest. 2. The yield in lumber per cubic foot of actual volume is relatively smaller for small logs than for large on account of the larger per- centage of waste involved in sawing lumber therefrom. Costs per cubic foot of volume would be less unfavorable to the smaller sizes, and on this basis the ratio between the costs of 18- and 48-inch trees is further reduced to 1% to 1. This fact has obviously little practical significance, however, in connection with present-day manufacturing methods. 3. The remaining important factor is the large amount of time which must be spent on every tree and on every log regardless of its size and which, in the case of small trees, must be charged against the small volume obtainable. In conclusion, it is not intended to point a moral with these figures. They are, in themselves, striking, and suggest many lines of thought and further investigation. In particular the question arises as to whether, in the subsequent handling of the logs, both in the woods and in the sawmill, the same relatively high costs will apply to the product of the smaller trees. The relative value of the lumber product of large and small trees is also a point at issue. Data have already been gathered on some phases of these questions which will be published at a later date. STATION PUBLICATIONS AVAILABLE FOR FEEE DISTRIBUTION BULLETINS No. No. 185. Report of Progress in Cereal Investiga- 299. tions. 300. 241. Vine Pruning in California, Part I. 304. 246. Vine Pruning in California, Part II. 251. Utilization of the Nitrogen and Organic 308. Matter in Septic and Imhoff Tank Sludges. 253. Irrigation and Soil Conditions in the 309. Sierra Nevada Foothills, California. 261. Melaxuma of the Walnut, "Juglansregia." 310. 262. Citrus Diseases of Florida and Cuba 312. Compared with Those of California. 313. 263. Size Grades for Ripe Olives. 316. 266. A Spotting of Citrus Fruits Due to the 317. Action of Oil Liberated from the Rind. 318. 267. Experiments with Stocks for Citrus. 320. 268. Growing and Grafting Olive Seedlings. 321. 270. A Comparison of Annual Cropping, Bi- 323. ennial Cropping, and Green Manures on the Yield of Wheat. 324. 271. Feeding Dairy Calves in California. 273. Preliminary Report on Kearney Vineyard 325. Experimental Drain. 275. The Cultivation of Belladonna in Cali- fornia. 328. 276. The Pomegranate. 330. 278. Grain Sorghums. 331. 279. Irrigation of Rice in California. 332. 280. Irrigation of Alfalfa in the Sacramento 334. Valley. 282. Trials with California Silage Crops for 335. Dairy Cows. 283. The Olive Insects of California. 336. 285. The Milk Goat in California. 286. Commercial Fertilizers. 337. 287. Vinegar from Waste Fruits. 339. 294. Bean Culture in California. 297. The Almond in California. 340. 298. Seedless Raisin Grapes. The Use of Lumber on California Farms. Commercial Fertilizers. A Study on the Effects of Freezes on Citrus in California. I. Fumigation with Liquid Hydrocyanic Acid. II. Physical and Chemical Pro- perties of Liquid Hydrocyanic Acid. I. The Carob in California. II. Nutritive Value of the Carob Bean. Plum Pollination. Mariout Barley. Pruning Young Deciduous Fruit Trees. The Kaki or Oriental Persimmon. Selections of Stocks in Citrus Propagation. The Effects of Alkali on Citrus Trees. Control of the Coyote in California. Commercial Production of Grape Syrup. Heavy vs. Light Grain Feeding for Dairy Cows. Storage of Perishable Fruit at Freezing Temperatures. Rice Irrigation Measurements and Ex- periments in Sacramento Valley, 1914- 1919. Prune Growing in California. Dehydration of Fruits. Phylloxera-Resistant Stocks. Walnut Culture in California. Preliminary Volume Tables for Second- Growth Redwoods. Cocoanut Meal as a Feed for Dairy Cows and Other Livestock. The Preparation of Nicotine Dust as an Insecticide. Some Factors of Dehydrater Efficiency. The Relative Cost of Making Logs from Small and Large Timber. Control of the Pocket Gopher in California. CIRCULARS No. No. 70. Observations on the Status of Corn 165. Growing in California. 82. The Common Ground Squirrels of Cali- 166. fornia. 167. 87. Alfalfa. 169. 110. Green Manuring in California. 170. 111. The Use of Lime and Gypsum on Cali- fornia Soils. 172. 113. Correspondence Courses in Agriculture. 173. 115. Grafting Vinifera Vineyards. 174. 126. Spraying for the Grape Leaf Hopper. 175. 127. House Fumigation. 128. Insecticide Formulas. 176. 129. The Control of Citrus Insects. 130. Cabbage Growing in California. 177. 135. Official Tests of Dairy Cows. 178. 138. The Silo in California Agriculture. 179. 144. Oidium or Powdery Mildew of the Vine. 148. "Lungworms." 181. 151. Feeding and Management of Hogs. 182. 152. Some Observations on the Bulk Handling of Grain in California. 183. 153. Announcement of the California State 184. Dairy Cow Competition, 1916-18. 188. 154. Irrigation Practice in Growing Small 189. f'i nits in California. 190. 155. Bovine Tuberculosis. 193. 157. Control of the Pear Scab. 198. L58. Borne and Farm Canning. 201. 159. Agriculture in the Imperial Valley. 202. 160. Lettuce (Growing in California. 161. Potatoes in California. 203. 164. Small Fruit Culture in California. 205. Fundamentals of Sugar Beet Culture under California Conditions. The County Farm Bureau. Feeding Stuffs of Minor Importance. The 1918 Grain Crop. Fertilizing California Soils for the 1918 Crop. Wheat Culture. The Construction of the Wood-Hoop Silo. Farm Drainage Methods. Progress Report on the Marketing and Distribution of Milk. Hog Cholera Prevention and the Serum Treatment. Grain Sorghums. The Packing of Apples in California. Factors of Importance in Producing Milk of Low Bacterial Count. Control of the California Ground Squirrel. Extending the Area of Irrigated Wheat in California for 1918. Infectious Abortion in Cows. A Flock of Sheep on the Farm. Lambing Sheds. Winter Forage Crops. Agriculture Clubs in California. A Study of Farm Labor in California. Syrup from Sweet Sorghum. Helpful Hints to Hog Raisers. County Organizations for Rural Fire Con- trol. Peat as a Manure Substitute. Blackleg.