44 THE COMMERCIAL HICKORIES. 



Two pignuts and 6 mockernuts came from eastern Maryland and 

 were selected in the yard. The other trees were obtained from 4 

 different woodlots. 



The material is typical of the hickory cut in this locality. In age 

 it ranges from 70 to 240 years, but most of the trees are from 150 to 

 200 years old, with diameters of from 14 to 20 inches, and heights of 

 from 80 to 100 feet. 



The cutting was done in March. The material was shipped partly 

 in April and partly in May. 



CARE OP MATERIAL. 



From each of these trees 1 flitch was cut through the center of the 

 butt log from bark to bark. The flitches were 4 inches thick and 

 from 7 to 12 feet long, depending on the length of the log. From a 

 few trees flitches were secured from the upper logs, and the entire 

 merchantable boles of two pignuts from Pennsylvania were used to 

 determine the strength as affected by height in the tree. 



Upon arrival at the laboratory the flitches were cut into sticks 

 2J by 2J by 30 inches, and the specimens intended for green tests 

 were immersed in water until the time of test to preserve them in 

 the green condition. The temperature of the wood at the time of 

 test was about the same for all specimens, so that the relative strength 

 would not be affected by this cause. Shortly before the time of test 

 the specimens were removed from the water, planed to 2 by 2 inches, 

 and sawed to a uniform length of 28 inches for the bending test. 

 After the bending test specimens were cut from the uninjured por- 

 tion of the beam for other tests. 



In cutting the individual test pieces from the flitches no attempt 

 was made to select pieces which might yield the highest results. 

 However, specimens were selected so as to avoid shakes and culls 

 and to include the various kinds of growth found in any given flitch, 

 and specimens that contained visible defects which would certainly 

 lower the strength were not included in the tests. 



METHODS OP TEST. 



The specimens were all accurately measured and weighed, the per 

 cent of sapwood measured, and the number of rings per inch counted. 

 The nonporous part of the annual rings was measured and its pro- 

 pro tion given in per cent of the whole growth; the moisture content 

 was determined in per cent of oven-dry weight. 



Static bending tests are the most important of the tests made. 



Beams 2 inches square and 28 inches long were supported on knife 

 edges 26 inches apart. Plates and rollers were used to avoid crushing 



a The methods of test were those described in Circular 38, Forest Service, entitled 

 "Instructions to Engineers in Timber Tests." 



