Castellamonte clay

Sentences without a label are documented facts; the others are marked "probable" or "uncertain".

Clay has been fired at Castellamonte since at least 1499: first cooking pots and bowls, then, from the end of the eighteenth century, stoves and fireplaces. This page follows the clay from the quarries in the hills to the grinding mills driven by the water of the Orco, to the peat- and wood-fired kilns and to the factories of the nineteenth century. The explanations of chemistry and physics are the general ones found in textbooks; the temperatures of the Castellamonte kilns are not given in the sources read.

The clay of the hills

For centuries the Castellamonte area has worked the red clay of the Canavese hills, dug from the badlands probable. The press release of the 2017 Ceramics Exhibition places the quarries at the “castelletti”, in the hamlet of Sant'Anna Boschi. According to Cima the clay had been dug for centuries from the badland banks of the Castelletti, in the area of the hamlet of Filia. The two sources do not name the same hamlet. On the hill of Filia there are still large red clay quarries, worked above all by the tile makers of Sassuolo.

There is not just one clay. In 1837 Casalis lists in the area plastic and ochreous clays and a “kaolin clay” from Monte Spinai, at Spineto, and from the “Benne”, used for porcelain. The grey clay is used for stoves, large tiles, muffles and tableware that withstand high temperatures. At the end of the nineteenth century the Buscaglione firm takes its clays from Val di Rimes, Violetta and Talentino at Spineto, from Filia and from the Banasso. Clays are also imported from Sardinia, from Vicenza and from France; the kaolin comes from Palestine.

Clays, in general, are made of very fine-grained minerals that become plastic with water: they can be shaped and they hold their form. Kaolin is a light-coloured clay used for porcelain. The red colour of terracotta normally comes from iron oxides. A clay that withstands fire without deforming is called refractory. Castellamonte supplied the Turin arsenal with large quantities of clay for the moulds of cannons, paid 1 lira and 8 soldi per rubbo. The crucibles of the Giovando copper forge at Sparone were also made with refractory earth from Castellamonte. What the chemical composition of these clays was, the sources read do not say.

Sources: Mentelocale 2026; Città di Castellamonte 2017, p. 4; Cima 2025b, pp. 241, 243; Giorda 1992, pp. 2, 7, 8; Cima 1987, p. 46

From cooking pots to stoves

Castellamonte pottery is much older than the eighteenth century. The land register of 1499, quoted by Giorda, names two kilns: one along the rio Gregorio and one in the Sansuario area, on the rio San Martino. In 1634 Turin puts a duty on the “glazed Castellamonte pots, large, medium and ordinary” and on the “cages of glazed and ordinary earthenware”. Together with the pots, the most widespread local product was the slip-decorated bowl, sold by pedlars. The Reasso family is already mentioned in the seventeenth century: on a bas-relief of the Madonna in via Massimo d'Azeglio one could read, until a few years before 1992, “Famiglia Reasso. 1638”.

The “Descrizione” of 1752-54 writes that the inhabitants work the land and make “terracotta vases” to take and sell “in the other places and provinces”. Cima deduces from this an itinerant trade, perhaps seasonal. The land register of 1784 records the “pot kilns” of the Mussa family along the rio Leonatto, of the Vernetto, of the Vallo at San Grato, of the Antonietti, already active in 1774, and of the Reasso at San Rocco. From these kilns, Cima and Giorda write, probably came the vases and capitals of the church of San Rocco, of 1777.

At the end of the eighteenth century the first stoves and the first “Franklin” fireplaces are made at Castellamonte. In 1838 Casalis writes that Pietro Reasso, with a workshop in vicolo Franklin, made the first fireplace with air circulation and a visible fire, later called the Franklin, and sold it for 300 lire. In 1888 Bertolotti adds that before then garden vases, oven tools and “Castellamonte pots” were made, and that Enrico Pagliero refined Reasso's “pianelloni” for stoves. Turismo Torino writes that the working of the red earth “developed at the end of the eighteenth century”: the documents of 1499, 1634 and 1784 show that pottery had already been there for centuries.

The classical-style stoves of Castellamonte take up models found in the residences of the House of Savoy and of the Piedmontese nobility, in Russia and in other countries. The Ceramics Museum in Palazzo Botton keeps parts of stoves from the seventeenth to the nineteenth century, fragments of friezes and capitals, tableware and “Franklin” firedogs probable.

A little physics, in general. An open hearth heats the room mainly by radiation, while much of the hot air rises up the flue. In a fireplace with air circulation the air of the room passes around the hearth, is heated by contact with the hot walls and returns to the room: this is convection. A stove with thick ceramic walls stores heat while the fire burns and releases it slowly even afterwards. How the Castellamonte stoves were made inside, the sources read do not describe.

Sources: Cima 2025b, pp. 163, 164, 241; Giorda 1992, pp. 3, 4; Turismo Torino, information sheet; Città di Castellamonte 2017, p. 2

The fire: kilns, muffles and peat

In the nineteenth century the Castellamonte kilns are peat- and wood-fired furnaces, which grow with muffles and reverberatory chambers. For the high temperatures peat from San Giovanni, Torre and Alice is burned; around 1820 Giuseppe Bertola burns in his kilns peat from the bogs of San Giovanni dei Boschi. The temperatures of the kilns are not given in the sources read.

What these parts are, in general. The muffle is a closed chamber inside the kiln: the pieces are fired without touching the flame and the fumes, which could stain them. In a reverberatory kiln the flame passes over the load and the vault reflects the heat downwards. In the house of the Allaira family, formerly a ceramics factory, the large “downdraught” firing kiln survives: in a kiln of this type the flame rises to the vault and is forced to come down through the pieces before leaving at the bottom, so the heat is better distributed. Peat is a fuel formed from plant remains accumulated in peat bogs.

The sources give some figures. In 1851 Antonio Galeazzi, from Pont, has 35 workers, horse-driven mills, two peat-fired kilns, one reverberatory kiln and two muffles, and uses about 1,000 tonnes of clay. In 1885 the Buscaglione firm has about forty employees and three large kilns of about 550 pieces each, uses over 900 tonnes of clay and makes about 150,000 pieces a year. At the Fornace Pagliero a nineteenth-century firing chamber survives, with acroteria and stacked vases.

Not everyone had a kiln. Before the Hoffman kiln many craftsmen of Filia and Spineto made bricks, roof tiles and curved tiles on the threshing floor with rough moulds and fired them in the “pignone”: the bricks stacked with holes for the wood and channels for the heat, which were often left half raw. In 1882 Giacomo Cola builds at Filia the first local Hoffman kiln, with continuous firing, active until around 1970; its ruins remain. In a Hoffman kiln, in general, the chambers are set in a ring and the fire moves from one chamber to the next: while one is firing, the others are being loaded, heated by the fumes or cooled, so the kiln never goes out.

What happens to clay in the fire, again in general. As it dries, the piece loses the water that made it plastic and shrinks a little. During firing it also loses the water bound in the minerals, which change their structure; at high temperature the particles fuse together. The fired piece never turns back into clay, not even in water. A badly fired piece, like the half-raw bricks of the pignone, stays fragile. The “glazes” of the 1634 pots are coatings that melt during firing and form a glassy layer: they close the pores and make the vessel watertight.

Sources: Città di Castellamonte 2017, p. 5; Giorda 1992, pp. 1, 5, 6, 7, 8; Cima 2025b, p. 243

The water that grinds

Before firing, the clay must be ground and kneaded; the glazes are ground too. In the nineteenth century the larger firms drive the mills for clay and glazes with water wheels, on the Roggia dei mulini and on the Canale di Caluso; others use horses. The Canale di Caluso takes the water of the Orco at Spineto, near Castellamonte, and runs for 28 km as far as Mazzè. Around 1820 Giuseppe Bertola is the first to use a water wheel on the Canale di Caluso to grind clay.

At the Fornace Pagliero a plant driven by a water wheel, installed in 1845 and used until a few years before 1992, served about 100 workers. With gears, pulleys and belts it drove the “molassa” or “pista” for the clay, the drum mills for the glazes, an extruder for pipes and a goods lift. In the drum mills the balls were stones from the Orco. Where the wheel took its water is not clear: Giorda places the Fornace along the mill race, Cima writes that the wheel was fed by the Canale di Caluso uncertain.

The physics of this plant is that of all water machines. The wheel turns the energy of the water into the rotation of a shaft; gears, pulleys and belts carry the motion to several machines and change its speed. In a drum mill, in general, a cylinder turns with hard bodies inside that roll and strike the material until it is reduced to fine powder: at the Pagliero they were pebbles from the river.

The water belonged to everyone, under certain conditions. In 1870 the Town Council authorises the conversion of the centuries-old “hemp pounding mill” on the Roggia near the Maglio into a clay mill open to all craftsmen. The Scavarda family sets up a grinding water wheel at via Massimo d'Azeglio 41 and a Pollino has a glaze mill available to others. Michele Stella builds a second factory in canton Perotti, along the Naviglio di Caluso. Around 1863 Antonio Galeazzi builds a works with a water wheel on the Roggia. At the Industrial Inquiry of 1870-1874 the potters write that three factories run on water power and twelve by ordinary means.

The link between clay and the Orco, then, runs through the wheels on the Roggia and on the Canale di Caluso and through the Orco stones in the glaze mills. A study of the nineteenth-century stoves and the certain date of the school are still missing uncertain.

Sources: Giorda 1992, pp. 1, 2, 3, 4, 5, 6; Cima 2025b, p. 242; FAI, information sheet

The nineteenth-century factories

According to Cima, with the Congress of Vienna the first ceramics industry is born at Castellamonte, making pottery, terracotta and refractories for metallurgy, with tableware, fireplaces and stoves. The oldest factory still active in 1992 is the one founded in 1814 by Enrico Pagliero in canton Morlino, at the entrance to Spineto. After Michele, Romualdo, Terenzio and Micheluccio it is run by the Camerlo brothers. Abbonamento Musei presents it as the passage from craft to industrial production probable. The press release of the 2017 Exhibition writes instead that the complex stands where the Pagliero Michele works was born “at the end of the eighteenth century” and that it keeps a kiln from the early nineteenth century: the two dates still have to be reconciled.

In 1860 just over 200 workers and craftsmen work in ceramics, with 20 cartloads of products a day. There are 5 factories with more than 30 employees, with at least another 20 craftsmen and twelve kilns for bricks and tiles. At the end of the century there are 18 factories, with more than 600 employees. Giacomo Buscaglione, who came from the Biellese, opens in 1830 and reaches a second works, one in Turin for stove fitting with about 200 employees and branches in many cities; in 1922 the factory passes to the Allaira family. Michele Stella makes stoves, tableware, tiles, porcelain, refractories and stoneware pipes for the chemical industry, and wins medals in Turin in 1858, 1871 and 1884. The Pollino, Allaira and Pagliero families form the “ceramics dynasties”; in 1905 Pagliero, Allaira and others promote on the Canale di Caluso the Industria piemontese del gres ceramico, abandoned a few years later.

At the Industrial Inquiry the potters say they supply heaters to government offices and bricks and refractory clay to the Arsenal, the Mint and the schools of chemistry. They ask for a railway, lower tariffs and a school, because good modellers and chemists are lacking. The “Felice Faccio” art high school was born as the Royal School for the art of ceramics; according to its head teacher the School of Art was established in 1922 to train the factory workforce. An article of 2026 traces it back to a school “founded at the end of the nineteenth century” probable: the two dates do not match.

For Giorda the nineteenth century is the century of greatest splendour. The products go to Lombardy, Liguria, Veneto, Emilia and central Italy; stoves, fireplaces, lemon-tree pots and clays also go abroad, reportedly as far as St Petersburg, Argentina and California.

Work had its ranks. In 1885 at the Buscaglione firm the throwers and moulders, on piecework, earn from 2.50 to 3 lire a day and the labourers 1.40. The apprentices, boys aged 11 to 15, after two years of unpaid training are paid from 30 to 60 centesimi a day. Alongside the well-known potters worked dozens of craftsmen in small workshops often made out of stables, helped by an apprentice or two or by relatives free from work in the fields. At the end of the nineteenth century the workers, who sometimes worked more than 11 hours a day, begin to agitate over hours and pay; in the first decade of the twentieth century this turns into strikes. The Society of artists and workers, founded in 1849, opens evening drawing classes and a lending library.

Sources: Cima 2025b, pp. 242, 245; Giorda 1992, pp. 1, 2, 3, 4, 5, 6, 7, 8, 9; Abbonamento Musei, information sheet; Città di Castellamonte 2017, pp. 4, 6; newsistruzione 2026

What remains

With the Second World War the Fornace Pagliero begins to decline; in 2003 it is bought by a potter, who resumes production with the original moulds found on site probable. The Fornace keeps three production lines, from the nineteenth century, the Thirties and the Fifties probable. Period equipment, moulds and dies and the nineteenth-century firing chamber are kept there; OpenStreetMap marks it as “Museo Ceramico Fornace Pagliero”, at Spineto. It is a ceramics centre and museum with an entrance ticket probable. At Filia the ruins of the Hoffman kiln remain.

The Ceramics Museum in Palazzo Botton has a historical section and a modern one with works donated by the artists; admission is free probable. At the 2017 Exhibition there are the stoves of today's local producers, alongside designer and art stoves. The “Felice Faccio” high school takes part in the Exhibition and trains the new potters. The 65th Exhibition is held from 22 August to 13 September 2026 in 16 venues probable.

Sources: Abbonamento Musei, information sheet; Città di Castellamonte 2017, pp. 2, 3, 6; OpenStreetMap, node 6428236215; Cima 2025b, p. 243; Giorda 1992, p. 8; Turismo Torino, information sheet; Mentelocale 2026

For the class

First: in 1885 the Buscaglione firm has three large kilns of about 550 pieces each and makes about 150,000 pieces a year. Calculate how many firings a year are needed if the three kilns work full at the same time. The sources read do not say how long a firing lasted: discuss what you would need to know to say whether the number is plausible. Second: Casalis writes that the grey clay is used for stoves and muffles because it withstands high temperatures. Explain why the muffles in particular, which stand inside the kiln, must be made of refractory clay. Third: the bricks fired in the “pignone” were often left half raw. Using what you know about firing, explain why a stack of bricks heated by holes filled with wood fires unevenly and what changes in a closed kiln with continuous firing such as the Hoffman.

Sources: Giorda 1992, pp. 2, 7, 8; Città di Castellamonte 2017, p. 5