PROFESSOR J. A. EWING ON EXPERIMENTAL 
This difference of behaviour appears, in fact, to form a criterion by which we may 
without fail distinguish a strained from an annealed piece. 
No. 1. 
No. 2. 
§ 80. To illustrate the subject of § 78 the following experiments may be cited. 
The wire of § 76, now 0‘76 mm. in diameter, was re-annealed in the vertical 
position three times over. When it had become cool, the magnetometer reading was 
found to be 159 (from the zero of magnetism). Then 1 kilo, was applied, and the 
reading jumped up to 220. Removal of the weight brought it to 218. The same 
weight was reapplied and removed several times, each time with the result that on 
gave rise and off gave fall of magnetism, while the successive operations gradually 
increased the magnetism. Then the range of loading was extended. Thus :— 
