Page:Transactions of the Natural History Society of Northumberland, Durham, and Newcastle-upon-Tyne 1838 Vol.2.djvu/176

162 the hearths usually go on 12 hours, and are suspended 5; four and a half or five bings of ore (36 to 40 cwt.) are smelted during a shift, and the two men, who manage the hearth, each work four shifts per week; terminating their week's work at three o'clock on Wednesday afternoon. They are succeeded by two other workmen, who also work four 12-hours shifts; the last of which they finish at four o'clock on Saturday. In these eight shifts, from 36 to 40 bings of ore are smelted, which, when of good quality, produce from 9 to 10 fodders of lead. At other mills where the shift is fourteen or fifteen hours, the furnace is kindled at four o'clock in the morning, and worked until six or seven in the evening each day, six days in the week; during this shift, 5 or 5½ bings of ore are smelted, and two men at one hearth, in the early part of each week, work three such shifts, producing about 4 fodders of lead—two other men work each three shifts in the latter part of the week, making the total quantity smelted per week, in one hearth, from 30 to 33 bings. Almost at every smelting mill a different mode of working, in point of time and quantity, is pursued; in some cases the quantity of ore smelted in one hearth, in a week, by four men, is 40 bings; but a fair rate of working is from 30 to 35 bings per week.

The quantity of coal required to smelt a fodder of lead, as has been already stated, varies with the quality of the ore. When this latter is of moderate goodness, 8 Winchester bushels, or 6 cwt. avoirdupois, are sufficient to smelt 18 or 20 bings; but, when the ore is refractory, the quantity required is very considerably greater. In general, from 8 to 12 Winchester bushels of coal, or from 6 to 9 cwt., are consumed during four smelting shifts of twelve hours each; and, as the quantity of lead made during this time is from 4½ to 5 fodders, the coal consumed is, after the rate of, from 1½ to 2 cwt. per fodder. The quantity of peats used in the same time is about four small cart loads, being something less than a cart load per fodder of lead. The lime expended is about 12 Winchester bushels, or something below 3 bushels per fodder of lead.