RIEHLE-GRAY AUTOGRAPHIC APPARATUS. 



just beyond it. There is an arrangement by means of 

 which high multiplications can be made use of throughout 

 the test. This is effected by bringing the pencil back to 

 zero each time it approaches the edge of the paper. The 

 radical difference between this apparatus and the Biehle 

 instrument is in the manner of obtaining the load ordinate. 

 The use of the poise weight is dispensed with for the time 

 being, and the load on the specimen is made to lift the 

 weighing lever against the tension of the spiral spring 



Sectional area of bars = 1 sq. in, 



PER CENT 

 40 



30 



I 20 



10 



B 



25 



20 



15 



10 



Load in Tons. 

 A Mild steel. 

 B Copper. 



FIG. 112. Copies of Self-recorded Diagrams, taken on a Wicksteed Test 



Recorder.* 



shown in the illustration. The outer end of the beam has- 

 a vertical motion of several inches, its height at any 

 moment depending on the load on the specimen. By 

 means of a cord this movement of the weighing beam is- 

 transmitted to the paper drum, which it causes to rotate. 

 The poise weight may be used to check the readings given. 



* See Inst. Mech. Eng. Proc., 1886. 



