210 
76 
77 
79 
80 
SL 
REPORTS ON THE STATE OF SCIENCE.—1913. 
elastic limits in tension; but the latter appear to have had an unusually 
low ratio to the tensile strength. Thus :— 
——— 
Specimen of Wrought Tron Specimen of Steel 
Range of stress + 28,000 lb. sq. in. + 42,000 | 
Rest (to fracture) 2:5 10° (not broken) 3-31 x 10° 
| Tensile E. limit, 23,400 1b, sq. in. 38,300 lb. square inch 
Tensile strength, 50,510 1b. sq. in. 78,010 lb. square inch 
It is stated that the ‘set’ observed ‘ did not appear to have a notable 
influence in causing fracture until it reached -001 inch or -002 inch in a 
length of 10 inches.’ Rest was found to decrease the ‘set.’ It was noticed 
that the specimens were always perceptibly warmer in the middle than 
near the ends. The temperature increased with the amount of the ‘set.’ 
Three specimens reached a blue heat (about 300° C.); the break occurred 
where the shaft was coolest. 
The effects of a V groove and of a square shoulder were investigated. 
Some tests were made of flanged couplings, in which cracks commenced in 
the keyways. 
Spangenberg 1874 Ueber das Verhalten der Metalle bei wiederholten 
Anstrengungen. See ‘Handbook of Testing, A. 
Martens, or Unwin’s ‘ Testing of Materials.’ 
Stanton, T. E. 1905 Alternating Stress-testing Machine at the National 
Physical Laboratory. ‘ Engineering,’ Feb. 17, 1905. 
‘Sci. Abs.,’ 1905, No. 670. 
An investigation concerning the effect upon the calculated stresses of 
the friction of the author’s direct-stress reciprocating machine, and of the 
fluctuation of angular acceleration of the shaft. 
Do. 1906 Repeated Impact-testing Machine. ‘ Engineering,’ 
82, July 13, 1906. ‘Sci. Abs.,’ 1906, No. 1520. 
The specimen is 4 inch diameter, with V notch turned 0-40 inch diameter 
at bottom of V. It is placed on knife-edges 44 inches apart, and receives 
blows over the notch from a tup, and it is given a half-revolution between 
each blow. Maximum speed, 100 blows per minute. 
Do. 1907 A Factor in the Design of Machine Details. ‘ Engineer- 
ing,’ April 19, 1907. 
On the effect of sudden changes of section in machine members, with 
estimates of the reduction of resistance to alternating stress. 
Do. 1908 New Fatigue Test for Steel. ‘Journ. Iron and Steel 
Inst.,’ 76, 1908. 
Test in simultaneous abrasion and fatigue. No speed effect was found 
for speeds between 200 and 2,200 cycles per minute. 
Do. 1912 Recent Researches made at the National Physical 
Laboratory on the Resistance of Metals to Alternating 
Stress. Intern. Congress for Testing Materials. 
Paper V. 1, 1912. 
Stanton and 1905 On the Resistance of Iron and Steel to Reversals of 
Bairstow Direct Stress. ‘Proc. Inst. Civ. Eng.,’  clxvi. 
“Sci. Abs.,’ 1907, No. 373. 
Tests made on commercial materials of iron and steel, using Stanton’s 
direct-stress machine (No. 77); cycles 800 per minute, the ratio 
maximum tensile stress of cycle 
maximum comp. stress of cycle 
being from 1-4 to 0-72. 
Results :-— 
No reduction in endurance was found at 800 per minute as compared 
with 60 per minute, thus agreeing with Nos. 23, 43, 65 and 80. 
