128 METALLURGY OF CAST IRON.
may be in the cupola, after which the breast will be opened and all dead ash and refuse lying in the "bed" will be raked out. After all dead material has been thus cleaned out, the breast will be firmly sealed up with tightly rammed sand, and all tuyere connections, etc., closed as above described. A little extra fuel being now put in and the top charging door closely sealed, the cupola will be allowed to stand in this condition until time to charge for the next heat, when the "bed" will be "replenished/' the cupola re-charged, and, after the breast has been replaced, the heat proceeded with as usual. How many times this operation can be repeated without '4 dropping the bottom '' can only be told by practice. In endeavoring to follow such a practice the management of the cupola must be in intelligent hands, as it can be readily seen that to charge a cupola ignorantly or carelessly, as is often done, would result in leaving iron at a level with the tuyeres, or all on one side of the cupola, so that it could not be melted at the end of a heat. These ideas are not presented with the expectation that all founders are going to drop their present methods to adopt the plans outlined; they are simply offered as suggestions to evolve ideas which may favor the inauguration of new practices that to-day might seem absurd and impracticable.
John C. Knoeppel, of the Buffalo Forge Co., Buffalo, N. Y., recently related to the author an experience in banking a cupola, which may often prove of benefit. In brief it is as follows: The blast had just been started and the iron was not yet down, when an accident occurred to the machinery, stopping the blast. As the damage could not be repaired withinwn any iron thatd three months of the Warwick Iron Co. of Pottstown, Pa. is often surprising how rapidly, as about 75 per cent of the heat generated from the solid fuel is utilized. This is attained where one ton of coke will produce one ton of iron; and Sir........................ 2,720 "