The load was gradually increased until it amounted to 12,950 Ibs., 

 when it tailed by shearing longitudinally. 



The maximum skin stress corresponding to the breaking load is 

 10,441 Ibs. per square inch. 



Tiie co-efficient of elasticity, as determined by an increment in the 

 deflection of .2-in. between the loads of 500 and 4500-lbs., is 

 2,178,100 Ibs. 



Table B gives the several readings. 



Beams IV to VIII were sent to the laboratory by the British 

 Columbia Mills Timber & Trading Company through Mr. C. M. 

 Beecher. 



These beams were cut out of trees grown on the coast section of 

 British Columbia, and felled in the fall or during the winter. The 

 whole of the beams were free from knots, of good quality, and with the 

 grain running straight from end to end. 



Beam IV was. tested May 17th, 1893, with the annular rings some- 

 what oblique as shown in Fig. 6. Under a load of 16,720 Ibs. it 



V/ nft afftr ftit. 



ft'gurc. C. 



failed by shearing longitudinally along a plane AB at right angles to 

 the annular rings, the distance between the ends of the portions above 

 and below the plane of shear being J-in. The plane of shear extended 

 to a distance of about 36 ins. from the end of the beam. 



The maximum skin stress corresponding to the breaking load is 

 4156 Ibs. per square inch. 



The co-efficient of elasticity, as determined by an increase in the 

 deflection of .14-in. between the loads of 2,000 and 8,000 Ibs., is 

 926,500 Ibs. 



Table B shows the several readings. 



After the beam had sheared longitudinally, the jockey weight was 

 run back, and the load again gradually applied until it amounted to 

 15,000 Ibs., when fracture occurred by the tearing apart of the fibres 

 on the tension face. Under this load of 15,000 Ibs. an opening of J-in. 

 was developed in the end at the plane of shear. 



On May llth this beam weighed 56 Ibs. 13 ozs., or 28.59 Ibs. per 

 cubic foot. On May 17th, the weight of the beam was 56 Ibs. 3 ozs., 

 or 28.27 Ibs. per cubic foot, so that while in the laboratory this beam 

 lost in weight at the ratejof ,0533-lb. per cubic foot per day. 



Beam V was tested on May 19th, 1893, with the annular rings 

 somewhat oblique as shown in Fig. 7. It failed by the tearing apart 

 of the fibres on the tension face under a load of 23,610 Ibs. 



fig. 7 



The maximum skin stress corresponding to this load is 5809 Ibs 

 per square inch. 



The co-efficient of elasticity, as determined by an increase in the 

 deflection of .24-in. between the loads of 1000-lbs. and 11,500-lbs., is 

 946,270 Ibs. 



Table B shows the several readings. 



The weight of the beam on May llth was 59 Ibs., or 29.59 Ibs. per 

 cubic foot. The weight of the beam on May 19th was 58 Ibs. 3 ozs., 

 or 29.18 Ibs. per cubic foot, so that the loss in weight in the laboratory 

 was at the rate of ,05125-lb. per cubic foot per day. 



6 



