Arte de louceiro: Tratado sobre o modo de fazer as louças de barro mais grossas

The manuscript opens with a practical guide for anyone who wants to turn raw earth into sturdy ceramic vessels. It begins by defining the craft of the “louceiro,” explaining how to recognize the right type of clay, how to cleanse and soften it, and why its fine particles give the material its characteristic pliability and resistance to water. The author describes the soaking, kneading, and “argamassar” processes in detail, showing how a well‑worked mass can be stretched on a wheel or shaped in molds without cracking.

Beyond the basics, the text moves on to the chemistry of firing, noting how heat transforms the pliant clay into a stone‑like body that can even withstand blows from steel. It contrasts this hardened earthenware with lime‑based mortars and highlights the importance of controlling shrinkage and moisture loss. For early‑19th‑century potters, the treatise offers a clear, step‑by‑step roadmap to producing thicker, more durable pieces of earthenware.