n of the wares, we
have ample written accounts of the methods and processes followed by
the Italian majolist. Mr Solon has recently published an epitome of
the account given in Biringuccio's _La Pyrotechnica_ (Venice, 1540),
and there is the memorable MS. of Piccolpasso, a potter of Castel
Durante, now in the library of the Victoria and Albert Museum, which,
besides giving an account of the processes, contains illustrations of
kilns, mills, decorative motives, &c.[16]

1. The potter's clay was prepared from mixtures of various kinds
prepared by (a) beating and picking out coarse particles, (b) mixing
with water, (c) passing through a sieve, (d) drying again into plastic
clay ready for the working potter. The essential point about the
potter's clay of the best tin-enamelled wares, whether Spanish,
Italian, French or Dutch, is that the clays are those known
geologically as "marls," which contain a large percentage of carbonate
of lime. Such clays always fire to a pinky red or buff colour, and
give a ware that is strong and yet light in substance, and on no other
kind of clay does the tin-enamel display its full perfection (see
Deck's _La Faience_). The analyses of certain tin-enamelled wares are
useful as showing the essential constitution of the best pottery
bodies for such purposes.

+----------------+---------+-----------+--------+----------+
| | Delia | Majolica. | Delft. | French |
| | Robbia. | | | Faience. |
+----------------+---------+-----------+--------+----------+
| Silica | 49.65 | 48.00 | 49.07 | 48.65 |
| Alumina | 15.50 | 17.59 | 16.19 | 17.05 |
| Lime | 22.40 | 20.12 | 18.01 | 19.43 |
| Magnesia | 0.17 | 1.17 | 0.82 | 0.27 |
| Oxide of iron | 3.70 | 3.75 | 2.82 | 4.33 |
| Carbonic Acid, | | | | |
| water, &c. | 8.58 | 9.46 | 13.09 | 10.27 |
+----------------+---------+-----------+--------+----------+

2. _Shaping._--The vessels were either "thrown" on the potter's wheel
(which had remained practically unaltered from Egyptian times), or
they were formed by "pressing" thin cakes of clay into moulds, made of
a composition of plaster (_gesso_), bone-ash and marble dust. In the
latter way all shapes that were not circular we