CHAP. XXXIV. Another way of making thrice calcin'd Copper with less charge and more ease.
WOrkmen who seek ways to spare their pains, will find this way of Calcination less Ex∣pensive than the others, and almost of equal beauty: Take the Scales which the Brasiers make when they hammer Pans, Kettles, or other works of Brass, as being much cheaper than new Copper. To calcine these Scales there is no need of Stratification as we have shewn before in other Copper, which is troublesom; they need only be well washed from all foulness; and being well dry'd, put them into one or more Crucibles, and set them just into the Mouth of the Reverberatory-Furnace for the space of four days: Being at length cool'd, pound or grind them and fearce them. Then set that powder a second time in the same Furnace to reverberate during four days longer; and you will have little Balls of a black Colour, which you must pound and searce again, and then put them the third time into the Reverberatory; and after four other days re∣duce them to powder as before; thus it will be prepared with less Expence, and as good to colour Glass, which will be easy to see by making tryal on melted Glass: For if it makes it rise when you cast it on, it is right.