ESSEX COUNTY, 



259 



Table of Experiments on the Tenacity of the Iron. 





a 5 



OBSERVATIONS. 



Completely 

 annealed. 



0.1890 

 0. 19-29 

 0.1954 

 O.I98r. 

 0.203G 

 0.2057 



10175 

 10-28S 

 10345.5 

 10374 



110-29.5 



53820 

 53336 

 52945 

 52-235 

 53941 

 53614 



Length before trial, 10 inches; after, 13-5; total elon- 

 gation, 35 per cent. Specific fp-a%-ity after trial, 

 7-685, 7-676, 7-668; mean, 7-676. After the 4th 

 fracture, the area of section was 0-1064 inch, in- 

 stead of 0-1986 as at first ; diminution 46 per cent. 

 Mean strength of this bar, 53311; greatest ditTe- 

 rence, 1706 lbs. = 3-2 per cent, of the mean. 



II. 



Hammer- 

 hardened. 



0.1980 

 0.-2019 

 0.2000 



1-2967.5 



13053 



13399.75 



65492 

 64650 

 66998 



Length before trial, 9-125 inches; after, 11 inches; 

 total elongation, 20-5 per cent. Specific gravity 

 after trial, 7-769, 7-756, 7-779; mean, 7-768. 

 Mean strength, 65713; greatest difierence, '2348 lbs. 

 = 3-5 per cent, of the mean. 



III. 



Hammered till 

 ncarlv black. 



0.1983 

 0.2151 

 0.2163 

 0.2213 



11970 

 1-2454.5 

 12768 

 1-2910.5 



60363 

 57919 

 590-29 

 58339 



Length before trial, 9-5 inches; after, 12--25; total 

 elongation, -28-94 per cent. Specific gravity, 7-760, 

 7-778,7-662; mean, 7-750. After tne -2d fracture, 

 the area of section at the point of fracture was 

 0-1176; diminution, 45-2per cent. Mean strength, 

 58912; greatest difference, 2444 lbs. = 4-15 per 

 cent of the mean. 



IV. 



Upset in the 

 centre and 

 annealed. 



0.2086 

 0.2-233 

 0.-2316 

 0.2-282 

 0.2354 



13110 

 136-23 

 13737 

 15162 

 15561 



6-2847 

 61007 

 59313 

 66441 

 66104 



Length before trial, 9; after, 11-2; total elongation, 

 24-46 per cent, of original length. Specific gravity 

 atler trial, 7-813, 7-731, 7-754, 7-634; mean, 

 7-733. Mean strength, 63142 ; greatest difference, 

 7128 lbs. = 11 -2 per cent, of the mean. The last 

 two restilts belong to the upset portion of the har ; 

 the thickest part of the upsetting remained, how- 

 ever, unbroken. 



Welded toge- 

 ther near 

 the middle, 

 hammered 

 till nearly 

 black. 



0.1845 



10773 



39585 



Broke outside of welding, 

 same as in No. III. 



The strength is about the 



