\. Tin' limber w.i- ol .1 i ( n.iht\ in llii- 



iii. irki'i, and tlii- nr.iin tin- tip- in-i-r IHM . I witli t.h- Rxfo. li 



contained .1 lew M-.I-OH cracks. ( III ill.' ti n-li.M t';ii-.- i.l tin- lirntll tin 

 I In. in lurk to IfiMil Ml a iil-1 iioiielii'l n 



I. Th o beam contained the ln-.ni ii.- annular 



' nro. 

 I 'id i tl loud .if .';.">, SIM! His. tin' IP MIII fiile I liy the (.- ii ou ii'.it'l "I' 



till- tilll'-- III! till- I, ll-ioll I 



Tin- maximum skin stress oi.rrcspnndiii:; in ibis |u.-nl I- fi .:i- : .-. |,.-i 

 ~|ila|->- ili.-li. 



Tlii- on i Hicient M| elasticity, a- determined !o.- .HI increase I" 

 ii ...... f .&46-in. between tin 1 load* of 2500 ami 15, 500 ll>-., i- 



I i lie I ' -how- tin- several reading-. 



Tli.- weight nl' tin- 1 cam was ">''"' 11". - "/- . r '>!.'>' 11)-'. |i'-r 



:;nl. an.l ."is:j ii"., i.i- :;i;.!t:Mi". HM- .-uiiic Hiot on Nm-. 



I Ith, ^liiiwinu a lui-; of woi^-lit in ill- Lil.n-ai.iry at tli- ratr nf . 

 II)-. pri- i-nl.ii- fi.iii ]n'i- il.iy. 



'Tallin l> -Ih-w- lli>- srvrral ruiulin-. 



The tiini- Mr.-ii|ii-il tiy the- tot \va~ 2:i ininu 



Hi-am XII was totfil XdV. l^th. !>!':;. with tin- ainiiiiai rin^s a~ in 

 l-'ii. r . 17. This bi'am wa> cut froni :i lu:i -S ins. 'in dtamoter, ^IMWH 

 probably about . '10 foot above the sen 1. v.-l at I'.n-t Hiw. about ci^ht 

 mill-- I'I-MIII \anciinvci-. Th tna- was I'cllc.l in Au;;u-t, 1SH2; it 

 n-uiaiiic'l in -alt waUT nine months, li<-ini;' aiteniately wt-t an.l dry 

 liu- in i he tide ; it was then lowed t-i the mill and cut up. 



Fig. 17. 



The grain wa.- straight and parallel to the axis, and the timber wa.- 

 . if good ijualiiy corresponding to first ijnality in the, marker. It .-hewed 

 several knot- of medium si/e and a fe'.v s.-ason cracks. The beam con- 

 tained the heart of the tree, the annular rings being as in Fig. 



1 mler a load ol 19,000 Ibs. the beam failed by shearing longitudinally 

 along the -eason crack A 13. 



Under thi.- load the maximum skin -;iv.-- is 7,iJ45 Ibs. per si|. in. 



The co etlifient of elasticity as determine t by an increment in the 

 detlei-ti.ms .-I ..">1."> ins. between the loads l!,.~>00-ll>s. and !.", 00(1 Ibs. i.- 



Tabli; I) .-h.-\v- the s-vcral r 



The tim. oi-cnpied by the tOSl wi- ^17 min : 



Th weight of the beam was T)!.' lb-.. n- .'!").0ii His. per cubic loot on 

 ird, and "j.'iS Ibs. I o/.s . or ill."'- 1 lb.-. per cubic foot on Nov. 17lb 

 showings 1"-- f weight ill llr- lah ir.itorv at lie- rate of.OlDl 1!. 

 per cubic foot p ] day. 



l!i-ani XIII. 'The history '. I' tliis Ii -am is the same as that of Beam 



IX The beam was ic-t d mi Xov. 17lh. IS'.i:;. 'The heart of the tree 

 wa- ii fib'- faces, the annular rings being as in Fig. IS. 



The timber was in good .-on liii.ni an 1 of a quality corresponding 

 to lir.-t quality in the market; there were small season cracks alon^ th. 

 back of the beam, in the neighbourhood of the neutral plane, and there 

 HI cracks along the whole .if the front alion! ''< in- 

 above the face in opmpressiooi 



Under a load of 21>,300 Ibs. this beam, failed by the crippling of the 

 tiln-es i.. 1 1 --on face, commencing at .1 small k- 



Ki- Ml. 



n 



