VOLUME OF WESTERN YELLOW PINE LOGS 617 



As shown in the table, this study covered practically one million 

 feet of lumber cut from 875,000 board feet of logs, with an average 

 overrun of 14.3 per cent. This is the highest per cent of overrun 

 obtained at any mill tally in California. The higher quality logs 

 gave only a comparatively small amount of overrun, because of large 

 size, slight taper and the production of a greater proportion of thin 

 lumber. The greatest overrun occurred in logs of poor quality, because 

 the majority of Grade III logs are top logs of small size and heavy 

 taper. The logs from which ties were cut gave over double the over- 

 run of those producing no ties. The overrun secured from defective 

 logs was somewhat less than that for sound logs. The total lumber 

 tally from defective logs was 12.5 per cent less than their gross scale. 

 Rough notes kept on waste determined that about 68 per cent of the 

 solid wood contents of the logs actually went into boards. 



The determination of overrun, or total lumber contents, is only 

 a secondary purpose of these studies. The primary object is to ascer- 

 tain the volumes of the logs in lumber grades. In this case the lumber 

 produced from the 3,662 logs involved produced 25.3 per cent of 

 uppers ; that is. No. 2 shop and better. This amount is about normal 

 for the yellow pine on the east side of the Sierras, and the stand from 

 which the logs came may be considered as quite representative of the 

 region. The essential differences between the three log grades are well 

 illustrated by the lumber tally. Grade I logs produced the bulk of the 

 clear, while Grade II logs ran less to clear and more to shop, and 

 Grade III logs cut little clear or shop. The per cents of the various 

 lumber grades comprised in the total lumber tally were as follows : 



These per cents may be used in estimating the quality of standing 

 timber by simply tallying the total estimated scale in each log grade on 

 a sample area. However, it is apparent that a more accurate estimate 

 may be made by using both log diameter classes and grades as a 

 basis. Therefore, in the office compilation of results, the data were 

 assembled by log grades and diameters, and the log scale and cut of 

 each lumber grade summarized for each log diameter. Tables were 

 then prepared showing the amounts and per cents of the various lum- 

 ber grades obtained from each diameter class of logs. Finally, these 



