METALLURGY OF CAST IRON'.
large mass and cooled very slowly it is not surprising that the fracture shows the iron in the mortar body to be much softer (or open-grained) than that in the test bars from the base ring. The tensile strength of the two specimens taken for acceptance of the 12-inch return mortar or lower base casting as above described was as follows:
No. r . . . 37,100 Ibs. No. 2 ... 37,000 Ibs.
TAHI.K 91.—TRANSVKKSK. TKSTS (>F < \\K-\VH KI-'.I. IK<»N.
1 . I 6 ! Common rule measurement. Mierom't'r' »)r.j] .... Broke at measure- *Hmi " *n ment. i "°"' pounds. Strength per square inch in pounds.
Rou^h bars. 19 I J4 in. s<]uare.........
22 i in. s<juarc ...... ..... HIJ in ,c"s its. .','s \\ •» \"f\
Rough bars. i,# in. duun ..... ..... IK fit in. ,i 1 1 in. 2 ;,.j«> ''^ :••••:•. ^
36 27 J:'-";5 ::::;•
Test bars furnished 1»v A. Whitney Kt Suns, I'hilmirlphia. l'»i. Trnlr*! by John R. Matlock, Jr., at the works of Kichlr Bros.' Tenting MavhineCo., rhilu-delphia, Fa,, June 27th, iH.^. Witness. W. C, Cutler.
In the chill roll iron, Table 90, pag'c 461, a few of the pieces were selected after having been broken
for transverse strength and pulled for the tensile strength. Bar Xo. 15 pulled 6,100 pounds; Nu. 16 pulled 23,700 pounds: and Xo. 17 pulled 30,100 pounds. The iron in the half-inch bars showed a white erystal-line fraeture, likewise the one-inch square. The one and one-eighth inch diameter rough bars showed a very close knit grain tending to a light color. The one and one-eighth inch turned bars are also very closeTested by Thomas D. West, at the works of the T. D. West Foundry Co , Sharpsville, Pa., Sept. i8th, 1894. Witnesses, Geo. H. Boyd andG. M. Mcllvain.