PART I FIELD WORK. 



THE STAND. 



At an elevation of 5,400 feet and growing in soil rich in moisture 

 and of volcanic origin, the forest in which this mill scale study was 

 conducted consisted of a stand in which western yellow pine (Pinus 

 ponderosa) predominated in association with a conspicuous growth of 

 white fir (Abies concolor) and an occasional Douglas fir (Pseudotsuga 

 taxifolia). The forest, located in the southern part of Lassen County, 

 California, is being exploited by the Red River Lumber Company. The 

 local topography is characteristically level with conspicuous rock out- 

 croppings so frequently encountered in sections of the yellow pine and 

 sugar pine regions of California. The uneven-aged stand cruises 

 approximately 25,000 board feet to the acre, and is characterized by the 

 presence of two distinct forms of yellow pine : namely, ' ' yellow pine, ' ' 

 averaging in height about 130 feet, and "bull pine" or "blackjack," 

 having an average height of approximately 120 feet. Although locally 

 known by these names, the two forms have been studied separately and 

 are referred to respectively as "mature yellow pine" and "immature 

 yellow pine," since it is believed that the variance is due solely to a 

 difference in age of trees of the same diameters. 



The rainfall is abundant but not heavy, and several small streams 

 drain the area and flow throughout the year. The region is one of an 

 open forest, free from abundant low growing species, and is further 

 characterized by numerous small mountain meadows, open glades in 

 which grass constitutes the main vegetation; these meadows vary in 

 si/(\ but seldom exceed twenty acres in extent except for the very large 

 meadows, which are frequently several miles across. 



The stand consists of trees of good quality, free from defects except 

 for the general fire-scarred butts which give evidence of past fires. 

 These scars are healed over and do not materially affect the quality of 

 the stand. The average age of the two forms of yellow pine are respec- 

 tively 350 and 250 years. The average diameter of the mature yellow 

 pine is about thirty-six inches and for the immature yellow pine about 

 twenty-eight inches. 



THE MILL. 



The mill operated by the Red River Lumber Company on its holdings 

 at Westwood, Lassen County, during the summer of 1913, was of 

 modern band-saw type, electrically equipped with separate motor drives 

 for each piece of machinery. Its capacity was 50,000 board feet for an 

 eleven-hour shift. The saw used was 16 gauge and 12 swedge one- 

 tenth inch thick with cutting edge one-eighth inch wide. The log 

 carriage was "shotgun" type limited to logs of not less than eight feet 

 and not more than twenty-four feet in length. The diameter of the 

 largest log that could be sawed was forty-six inches at the large end. 



These features of the mill influenced to a marked degree the final 

 results of the study, and are the only ones pertaining to the mill proper 

 deemed of importance in connection with this work. 



