The loll, niinryo!' tin- n -nil- .!>!. HIM- 1. lor 



Ue.l I'ine: 



co-efficient of elasticity in Ibs. per sq. in. = 1,520,056. 

 " maximum skin stress " " =5370. 



It', however, the plank results are omitted, 



The average weight in Ibs. per cubic foot = 34.78. 



co-efficient of clasticiiy in Ibs. per sq. in. = 1,434,747. 

 maximum skin stress " =5137. 



In general, the following data may be adopted in practice : 

 The average weight in Ibs. pnr cubic foot =34.6. 



co-efficient of elasticity in Ibs. per sq. in. = 1,430,000. 

 maximum skin stress " " =5,100. 



safe working skin stress ; ' " =1,700, 



3 being a factor of safety. 



In the accounts of thesevcral beamsit will be observed that the failures 

 are almost invariably due to the crippling of the material on the side 

 in compression, indicating that the tensile strength of the timber 

 exceeds its compress! ve strength, and this was subsequently verified by 

 the direct tension and compression experiments. 



WHITE PINK. 



Beams XXXVI ami XXXVII are two pieces cut out of one large 

 piece of square pine, made and taken out in the Gatineau Valley, 

 Ottawa County. The timber was brought down via the Gatineau and 

 Ottawa River- to Montreal, and remained in the water until late in the 

 fall of 1S','2, when it was piled on the land for winter sawing. 



This timber was purchased from Messis. J. & B. drier. 



Beam XXXVI was t<s!r<l I'Vliruary It'ith, 1S!(3, with the annular 

 r\\t'j.> as in Fig. 81. 



Tlie load upon the beam was gradually increased until it amounted 

 to 10,li(Hi II,-., when it failed by the tearing apart of the fibres on the 

 ten-iou side. 



The maximum >kin stress corresp<>n lini: to this load is 2993 lb. 

 per square inch. 25 



