On bronze casting generally (731-740).

731.

TO CAST.

Tartar burnt and powdered with plaster and cast cause the plaster to
hold together when it is mixed up again; and then it will dissolve
in water.

732.

TO CAST BRONZE IN PLASTER.

Take to every 2 cups of plaster 1 of ox-horns burnt, mix them
together and make your cast with it.

733.

When you want to take a cast in wax, burn the scum with a candle,
and the cast will come out without bubbles.

734.

2 ounces of plaster to a pound of metal;-- walnut, which makes it
like the curve.

[Footnote: The second part of this is quite obscure.]

735.