Blown-off (dishes, salts, &c.) is a term well known in the trade. Nearly all dessert dishes, especially those of an oval or square form, are made upon this principle. An oblong dish, of ten inches long, weighs about six pounds, and requires two or three gatherings of metal. When it has been well rolled and flatted into a crude square or other form upon the marver, the workman ascends the chair, and presses it into a brass mould previously placed upon the floor; urging the pressure by blowing, lifting it up repeatedly, and again, as it were, stamping it into the mould; and at last, increasing the inflation from the lungs, and greatly expanding the upper part of the dish called the blow-over, till it becomes so thin at parts as sometimes to explode. A piece of wood is used to knock off the lower part of the overplus, leaving the dish, of considerable substance, which is then turned out of the mould for annealing.

The above mode of blowing-off, as (A) distinguished from blown-over, (B) was of importance during the Excise laws, as it prevented duty being paid upon waste Glass; the plan is still practised, and with advantage. Blown-over, B, is similar to A, but less expanded upwards; the surplusage is, therefore, thicker, and must be flown off by the glass-cutter when cold, which incurs great risk. Whether dishes are to be cut or only moulded, the rough edges must, when annealed, be carefully pinched off, and shaped by the Glass-cutting wheels, preparatory to being finished in scollops, &c.