STkKXGTIf IN SPECIALTY MIXTUKKS.
second, the next best in strength, and so on, the last Table being" the weakest iron.
The test of the gun metal, Table 89, page 460, showed the planed bars of a very coarse grain partaking of a fibrous nature, somewhat after a good grade of wrought iron, having a fracture of a dark color. The metal of the rough bars showed the fracture in the one-half-inch square bar to be strictly white and in the one-inch square test bars to be of a crystalline mottled nature, and in the rough one and one-eighth inch
TAP.I.K «;o.—TKANSVKIiSK TKSTS <»!•' <'IIII,I, K<H.l. IRON.
Common rule measurement.
j... in. square.....
Strength per siiuare
inch in pounds.
SSH I, S,j i I, IK) .!,.V«
T<",t bat-, lurnishcd ]>y Lewis Foundry iS: Ma. itinc Co., Pit tsbniy., J'a. Tr'.!*il at thr works of M.Vonwav & T<»tl<-y, I'itlsbuir,, I'a., |tnir r;th. is-i.}, by | U. Nau, AlhT.lu-ny, I'a. Witn«-s-,cd by K. <*.. <'.. Moldrtikr, lv M , I'Ji. I>.
diameter bars of a similar character, but to a little less degree than shown in the one-inch 'square bars. The large opcn-graincd bars, or those of numbers 3, -1, ;^ 9i ln an(^ l l-> illnst rated in Table «S<), were planed from the rnuz/.le disc of a, i.»-iiu'li mortar casting, and bars i, .\ o, 7, ,s, i .* and i ($ were cast with metal which was used to pour a lower base ring for a. i :*-inch spring return mortal' carriage. The charge of iron for the mortar was very much harder than that used for the base ring, but as it was cast in a veryil/% in. diam. 1.139 in. .150 in. 3,320 3,258 ......