Page:History of the Royal Society.djvu/308

 'When the Powder is thus corned, it is laid about an inch and half thick on the drying Sieves, which are made of coarse Canvass fastned to slight frames of Deal about an Ell long, and some twenty inches broad; and thus it is carried into Stoves to dry.

'The Stove is commonly a little Room about eighteen or twenty foot square, with ranges of small Fir poles about two foot one above another, to lay the drying Sieves upon, but only on that side the fire is made. Besides a glass window to give light, there must be a small lover-hole at the top of the Room, to let out the steam, else the Powder will not only be the longer a drying, but often by the return of the steam on the Sieves, the top of the Powder will be so crusted that the lower part will not dry. The Room is heated by an Iron about a yard high and half a yard broad, cast in the form of an Arch, equal to a Semi-quadrant, and placed in the back of a Chimney, the fore part whereof is like a Furnace; and to avoid danger, opens into another little Room apart, called the Stoke-hole.

'The Powder is brought into the Stove before it be heated, and is not taken out again till the Stove be cold; and about eight hours is required to the drying of it. In hot Countries the Sun is the best Stove, and a great deal of danger and charges that way avoided.

'After the Powder is dried, it is brought again to the Corning-house, where it is again sifted over the Dusting bin in other double Sieves, but without any Runners. These Sieves have both of them smaller holes than the former: The upper Sieve is called the Separater, and serves to divide the great corns from the lesser; the great corns are put by Rh