In the third method the wax models are cut into small pieces,
powdered and moulded in clay, and set in the troughs as described
above. When the moulds are made, with due observance to the
undercutting (I say this advisedly), lead castings are made from
them, and these as well cleaned and worked up as the master may be
minded; then they are cast in silver in the same troughs as I told
you before. This is a particularly good way, because when the master
has his lead model and has finished it up to suit his purpose, it
can serve ever so many more times than a single casting.