along the annular rings tor a distance ul -I in-, mi .-ach side of the 

 centre a> in tlic ti'j'; 



Tlic iiiaxiiiitiin skm .-tn>s oormpooding to the broking load "t 



(i'lOII Ids. is 5412 His. per square inch. 



Tin- cu efficient of elasticity, us deduced fr Dm an incremeut in the 



dehYrtion of 1.085 ins. between tin- loads of'2000-lbs. and 5000 Ibs., \v:n 

 1, Ills. !()(! ll.s. 



Table I- shew- tin- -cveral rcadii. 



'I'lr- l.rain when tir-l |.l;,eed in position, also liud a camber of .35 in.-.. 

 in a central length uf 14 ft. I'. in,-. 



The weight of the benni on Mav 4th. tin' datr i.f test, was 165 Ihs. 

 (' (./>.. en- ;;|.'.)7 Ibs. per cubic t'"<i. 



Beams XXXII to XXX V might perhaps mure properly be designated 

 3 ins. planks. 



Beam (Plank) XXXII wastrel May 7th, 1894. The heart was 

 in one of the faces, and the annular rings wnv situated as in Fig. 72. 



The load upon the beam gradually increased until it amounted to 

 5200 Ibs., when it failed by a crippling of the fibres on the compression 

 side. The crippling occurred about H ins. away from the centre of 

 the beam and extended upwards about 1.5 ins. The load was still 

 increased, and when it amounted to 5860 Ibs. the beam again failed by 

 the tearing apart of the fibres on the tension side. A line of crippling 

 also extended upwards a further distance of about 2 ins., or about 3 

 ins. from the skin. 



The maximum skin stress corresponding to the breaking load of 

 5200 Ibs. is 6928 Ibs. per square inch. 



The co-efficient of elasticity, as deduced from an increment in the 

 deflection of 1.67-ins. between the loads 1000 Ibs. and 4000 Ibs., is 

 1,575,200 Ibs. per square inch. 



Table L shews the several readings. 



The weight of this beam on May 7th, the date of test, was 102 Ibs., 

 or 31. 56 Ibs. per cubic foot. 



Beam (Plank) XXXIII was tested May 7th, 1894, with the annu- 

 lar rin'js as shown in Fig. 73. 



The load upon the beam was gradually increased to 9250 Ibs., 

 when failure took place by the crippling of the fibres on the compres- 

 sion side, Fus. 74, 75. There were two lines of crippling on the front 

 and one at the middle of the beam at the back. The crippling 

 at the back probably occurred first, as the folding of the timber 

 extends across the section of the beam along tlic central line at the lower 

 edi:e, Lut not up to the point where the failure due to compression 

 was apparently the greatest. In the neighbourhood of the crippling 

 in front, the timber was clear, and thj grain ran straight and parallel 

 with the axis: at the back there were three knots, which were primarily 

 the cause of the crippling. 



When the load on the beam had been increased to 9900 Ibs., 

 fracture occurred on the tension side. 



The maximum skin stress corresponding to the breaking load of 9250 

 Ibs. is 6554 Ibs. per sq. in. 



The co-effieient of elasticity, as determined by an increment in the 

 dufliction of .70 in. between the loads 2600 and 6200 Ibs., i* 

 1,618,000 Ibs. 



Table M shews the several readings. 



23 



