Annealing of Cold Hard Steel. 



399 



nicate the data separately. The following results on the 

 secular annealing of cold glass-hard steel essentially sustain 

 the inferences of my last paper. They were omitted because 

 of the space occupied by the discussions there given. The 

 rods to which the data refer are of Stubs' s best steel, tempered 

 in a special apparatus*, by aid of which the wire heated to 

 redness electrically is suddenly whipped into water. Freshly 

 quenched samples of wire showed specific resistances (0° C) 

 as high as s=48< All the rods were tested for longitudinal 

 uniformity of temper by stepping off, as it were, the resistance 

 of lengths of 2 centim. each, for each of the consecutive 3 

 centim. of wire. The total length being about 25 centim., 

 eight measurements were thus made. A device utilizing 

 Matthiessen and Hoskin's method, and provided with a suit- 

 able rider, enabled me to do this with reasonable accuracy. 

 Table I. contains the results as obtained with three batches of 

 wire, of the diameters 2p = "081 centim., *044 centim., and 

 '127 centim. respectively. The approximate resistance 

 (microhms) of the 2 centim. of length is designated by r. 



Table I. — Longitudinal Uniformity of Temper of the Steel 

 Rods. Variation from Mean, in terms of the Electrical 

 Interval Hard-soft. 



No. 1. 



No. 2. 



No. 3. 



No. 4. 



No. 5. 



No. 6. 



No. 7. 



No. 8. 



No. 9. 



No. 10. 



r = 18500. 



18500. 



17700. 



17600. 



17700. 



18500. 



18400. 



18500. 



17400. 



17900. 



•002 



002 



•000 



•003 



•010 



•005 



•004 



•009 



•032 



•006 



4 



- 2 







- 2 



10 



- 3 



1 



- 11 



18 



- 6 



2 



- 2 



5 



- 2 



- 7 



- 7 



1 



- 11 



11 



2 



- 1 



2 



5 



7 



- 2 



5 



7 



5 



- 46 



2 



- 6 



- 2 



5 



- 2 



C 



1 



7 



- 3 



- 64 



- 2 



4 



- 6-13 



- 6 



- 7 



- 2 



- 5 



5 



- 16 



- 6 



1 



-2! 



- 2 



- 11 



- 7 



- 8 



5 



23 



10 



- 4 



10 - 4 



3 



2 



9 



- 5 



1 



41 



- 6 



1 

 No. 11. No. 12. So. 13. No. 14. 



No. 15. 



' No. 16. 



No. 17. 



No. 18. 



No. 19. 



No. 20. 



r=G1200. 60600. 61300. 60200. 



62000. 



r=6800. 



6760. 



6580. 



7290. 



6850. 



•007 



-•007 



-•003 



•023 



•016 



-•006 



•001 



-•009 



•001 



-•013 



- 2 



- 1 



- 3 



- 1 



- 1 



- 2 



1 



7 



1 



- 26 



- 7 



- 4 



- 3 



1 



- 3 



3 



5 



15 



10 



4 



- 10 



- 7 



- 10 



- 7 



- 9 



- 2 



- 3 



3 



10 



17 



1 



4 5 



- 4 



2 



- 2 



- 3 



- 1 



14 



13 



1 



- 1 



- 3 



- 4 



- 12 



- 2 



1 



11 



- 11 



13 



1 



4 



8 



- 4 



- 1 



3 



- 3 



- 5 



- 11 



- 13 



10 



13 



8 



- 4 



8 



7 



1 



- 20 



- 11 



4 



* Bulletin U. S. Geological Survey, No. 14, p. 29 (1885). My present 

 •apparatus is horizontal in form, and enables me to quench the wires from 

 any degree of red heat in water or other liquid at any desirable tempe- 

 lature. 



2 E2 



