ON STRENGTH AND PROPERTIES OF CASTIRON. 389 
Comparative results of Elsicar Cold Blast Tron, No. 1, and 
Milton Hot Blast, No.1. 
Distance between supports 4 ft. 6 in. 
Elsicar. 
Strength of the Cold Blast Iron. | Strength of the Hot Blast Eron. 
Milton. 
Ratio of the Strengths. 
Mean. * - Mean. 
435-2) yan, 3371] ono. 
oe } 430-4 367.9} 352°5 1000: 819 
904-2 | oyx. 7653 | ro, 
wee } 945:2 reo ta728 1000: 818 
Mean ratio of strengths ...... 1000 =: «818 
The products, and ratio to resist impact. 
Product of strength by 
ultimate deflection in 
Cold Blast Iron. 
Product of strength by 
ultimate deflection in 
Hot Blast Iron. 
Ratio of products, or 
of power to 
resist impact. 
Mean. Mean. 
672°3 | y 495-8 | - ao, i 
6316 f 652-2 580-9 [2883 1000 : 825 
309°2 ; 316-0 : F 
sary rade oasb \ 319-5 1000: 925 
Mean ratio of powers to sustain impact ... .. 1000. =: «875 
Modulus of elasticity in lhs. for a base of an inch square. 
Elsicar Iron (Cold Blast) 13410000 
Ditto ditto 14552000 
Mean 138981000 
11701000 
12248000 
Mean 11974500 
Milton Iron (Hot Blast) 
Ditto ditto 
The Elsicar and Milton being the only Yorkshire irons ob- 
tained answering to the description of hot and cold blast, it 
may be proper, in this part of my report, to state that I have 
been favoured with a series of experiments made at the Low 
Moor Works, near Bradford, by Mr. Dawson, one of the pro- 
prietors. In the year 1830 the hot blast was‘tried in the re- 
duction of the ores of the Bradford district. A number of bars, 
1 inch square, were cast from iron produced in the cold blast 
furnace of 1829, and a similar number of bars were cast, of the 
same dimensions, and from the same model and furnace, with 
hot blast, in 1830. Each of the bars was broken with weights 
