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smelt it in, as they who smelt the GlassMetal fpr making Glass, or in like Man-ner as a luted Crucible is placed in theFire, where the Force of the Fire acts thro*the Crucible, and fuses the Metal, withoutexposing it to the Air, or suffering theFire immediately to act upon it, contraryto the Smelting-Furnaces now in use. ThisPractice is intirely avoided by the Glass-Makers; for, was their Glass-Mixture cal-led by them Glass-Metal, nakedly exposedto the Air, and the Fire permitted to exertits Force upon it; and had they the likeChimnies as are used in the Lead-OreFurnaces, the Mixture of the Glass-Metalwould be destroy’d by the Exhalation ofits most essential Particles, which ought tobe taken into due Consideration by theFead-Smelters in this Country. I haveheard of an Attempt to retain the MetallineParticles, which are exhaled, by a Re-servoir of Water, placed in some Part ofthe Chimney ; but as this is not attemptedwith any Success, I shall not animadvertupon it; but will proceed to point out, i slParticular, what a Smelter ought to knowbefore he takes upon him to direct a Smelt-ing Work.

A Smelter, in the first Place, ought tobe an exact Assay Master ; that is, he mustfe a perfect Artist in trying Ores and Mi-nerals in small Parcels, in order to come to

A Know-