The mode of supplying the lime, coke, iron-stone, etc. to the crater, or tunnel-head of the furnace, was formerly by men carrying them in baskets up an inclined plane or bridge. Subsequently small waggons or corves were employed to take the materials up an inclined railway to the crater, by means of chains connected to the waggons, and passing round a drum or rigger, actuated by the steam engine, or other prime mover. In some instances the weight of a bucket of water descending into a pit was employed as the moving force to draw the loaded corve up to the top of the furnace, or hopper leading into it; where the corve, by being provided with a sliding bottom, to which was fixed a projecting bar, discharged its contents, by the bar coming against an obstruction, which pushed the bottom away, when over the discharging hole. The bucket also, on reaching the bottom of the pit, was discharged of its water, through a valve in its bottom being opened by coming in contact with a projecting pin at the bottom of the pit.

The motion was then reversed by the superior weight of the empty waggon, causing it to descend the inclined plane, and raise up the empty bucket for a renewal of the operation, by refilling the vessels, one with the mineral, and the other with the water.

In some situations the mode of raising the materials is by an endless chain passing round two riggers, one at each extremity of the inclined plane, the chain carrying two corves or buckets, one of which is being filled below whilst the other is being discharged above, in continuous succession; in a similar way to the scoops in dredging and excavating machines, described under their initial letters.