ON STRENGTH AND PROPERTIES OF CAST IRON. 413 
Comparative strength and power to resist impact of the Coed- 
Talon hot and cold blast irons, at various temperatures. 
Transverse Strengths. 
Temperature. | Coed-Talon Cold Blast. | Coed-Talon Hot Blast. Ratio 
: Fahrenheit. No. 2 Iron. No. 2 Iron, 
26° 851- 823°1 1000 : 967-2 
940°7 | Mean 933°4 | Mean : 
32 958°5 f 949°6 905-0 [ 919-7 id ith ha 
190 743°1 823°6 1000 : 110-8 
Red in dark 723-1 $29°7 
No. 3 Iron. No. 3 Iron. 
219 905-0 | Mean 818-4 1000 : 885-4 
943-6 [ 924:3 834:1 ] Mean 1000 : 847°7 
909-3 4 917°5 [ 875-8 
600 bed } 10331 
Power to resist impact. 
Temperature. | Coed-Talon Cold Blast. | Coed-Talon Hot Blast. Ratio, 
Fahrenheit. No. 2 Iron. No. 2 Iron. 
26° 349-8 340°8 1000: 974 
360°3 | Mean 406-9 | Mean on 
32 404°5 f 382-4 383-2 [395-0 waphedacteeis soot 
190 223°7 298-9 1000 : 1836 
Modulus of elasticity in lbs. for a base of | inch square. 
Temperature. Coed-Talon Cold Blast. Coed-Talon Hot Blast, 
Fahrenheit. No, 2 Iron. No, 2 Iron, 
26° 12994400 14267500 
32 18506700 | Mean 13723500 | Mean 
15148200 J 143827450 14283200 { 14003350 
190 14398600 13869500 
The above summary of results on the strength of the hot 
and cold blast irons is, with one exception, in favour of the 
cold blast. On the other hand, the power to resist impact 
appears, with one exception, also, on the side of the hot blast. 
Having prosecuted these inquiries through a considerable 
range both of time and temperature, and having united my 
efforts to those of Mr. Hodgkinson on the transverse strain, I 
shall, before closing this report, give a general summary, with 
the results of which he has kindly favoured me, from all the 
irons experimented upon in this way. 
Those results will exhibit in one column the relative and 
proportionate strength of each iron, and in the other the 
