KKKKt T <ĽK KXl'ANSIOX ON SH KIN K A<', K, KTC. -^7
avoid any method in melting-, favorable to the absorption of sulphur by iron in cupola or "uir furnace" practice. These considerations are applicable also to the making- of iron in the blast furnace.
The apparatus used for obtaining the expansion and contraction records, shown in Figs. 74 and 75, is shown in Figs. 76, 77, 78, and 79. It was designed by the author after much study of the conditions necessary for automatic record of the expansion and contraction of test bars, and also for the highly important purpose of simultaneous comparative tests.
The figures illustrating this apparatus (which is freely offered for use to all who may be interested in the matter) will be readily understood, with the aid of the following explanation:
In Figs. 76 and 77 the same letters indicate the same parts, namely: -
A, stationary or sliding recording face-plate board; B, float; I>, float-receptacle; R, regulator, giving constant head of water; K, supporting arm for the water-supply vessel; II, over-flow pipe; K, 1^ and M, recording arm lovers; N, lead-pencil recorder; O, rub her-band lever-supporter; R, curve-recording faceplate board; S, slide-guides for recording curves; T, revolving sheave-wheel guide and support; U, fulcrum cross-bar; Y, supporter of fulcrum cross-bar.
In Fig. 7K the parts are indicated by letters, as follows:
A, counterbalance clock-weight; H, bed-plate, se curing the base board; I, one-day 4* Pirate " alarm-clock; R, curve-rwonling fare-plate board; S, remova ble east ing-pin; IT, fulcrum eross-bar; V, clock and recording face-board connect ing-shaft.cient to injure or ruin almost any casting made f