282 
On  the  Elastic  Properties  of  Steel. 
combined  stresses  with  those  obtained  by  computing"  the 
formulae  : 
where  p  is  the  load  in  pounds  per  square  inch  in  simple 
tension,  p>s  the  shear  on  the  outer  fibre  in  simple  torsion,  and 
q  and  qs  the  normal  and  shearing  stresses  on  an  internal  plane 
of  the  material. 
Pig.  5. 
Xickel -Steel. — Torsion  part  only  of  Torsion-Tension  Tests,  "A/' 
and  Simple  Torsion  Test,  "B." 
44 
40 
36 
32 
28 
24 
20 
3: 
6- 
A 
£-— 
1 
ElAS 
TIC  Li. 
/ 
ELfiSJ 
>C  LlM 
IT 
<0 
/ 
/ 
<> 
/ 
< 
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f 
<X   /A 
ft/ID 
>/WS. 
0        .02      .04     .06      .08       .10      .12      .14      .16      .18     ..20 
In  conclusion,  the  writer  wishes  to  acknowledge  the 
efficient  work  of  several  senior  students  who  made  it  possible 
to  carry  out  the  tests  that  have  been  made :  Mr.  Carlos 
Robles  Gil,  Mr.  C.  E.  Shearer,  Mr.  F.  O.  Blair,  Mr.  W.  R. 
Wheeler,  Mr.  J.  H.  Lambert,  and  Mr.  J.  W.  Krull  ;  and  to 
acknowledge  particularly  the  helpful  suggestions  of  Professor 
W.  K.  Hatt,  in  charge  of  the  Laboratory  for  Testing- 
Materials. 
June,  1905. 
