The front of the plaque is contained within a rectangular porcelain frame surmounted by an elaborate cresting. The front is moulded in relief in minute detail with the elaborate mechanism for raising of the equestrian statue of the king.
This represents the first attempt to make porcelain in Portugal. Lieutenant Colonel Bartholemeu da Costa discovered small amounts of kaolin in some fire clays being tested for the building of kilns to be used in a foundry at the army arsenal in Lisbon in 1773 and produced a handful of experimental pieces of porcelain.
Because only small amounts of kaolin could be found at the time, da Costa’s experiments were limited to small plaques, medals and cameos. These were cast from the moulds created by the sculptor Machado de Castro and his colleague Joao Figuerido, a medallist who became the director of the engraving school at the arsenal. These were originally believed to have been made at the Fabrica do Cojo in Aveiro but it is now thought that the pieces from this early trial period may have been fired in the kilns of Real Fabrica do Rato, the royal faience factory in Lisbon.
Da Costa was an engineer and the plaque celebrates his apparatus for the erection of the equestrian statue, by Mochado de Castro, of King Joseph I of Portugal which still stands in Lisbon on the site where his palace was flattened in the devastating earthquake of 1755.
Various scrolls and passages of text on the front celebrate the process from conception to completion, saying that the statue was ‘suspended on 20 May 1775’. A further large inscription covers the reverse.
Inscriptions on the front:
Top (above the statue and suspension apparatus):
Suspendida em 20 de Mayo de 1775
Bottom right (on the scroll):
Fundida em 15 de outubro de 1774 co loca ca da em 26 de Mayo de 1775
Aberta com asistenota e de senho do ventor em 1775
Inscription on the reverse:
MAQUINA, COMQUE SE SUSPENDEO E LEVOU POR HUM ANGULO RECT FOR A DA CAZA DA FUNDICAO, PARA SE POR NO CARRO DE TRANSPORTE, A REAL ESTATUA EQUESTRE DE S. MAGESTADE FIDELISSIMA O SENHOR D. IOZE PRIMEIRO FUNDIDA DEHUMA SO VEZ SEM A MENOR FENDA EM A REAL FUNDIÇIAO DE ART.RA NA INTENDENCIA DO THENTE GENERAL DA ARTR.A DO REINO MANOEL GOMES DE CARVO.O E SILVA. INVENTADA PELLO BRIGADEIRO BARTOLOMEO DA COSTA, O PRIMEIRO, QUE EM PORTUGAL ACHOU PORCELANA, E DESCOBRIO ESTA NO MESMO TEMPO EM QUE IDEAVA, E CONTINUAVA O TRABALHO DE FUNDIR A REAL ESTATUA
LIFTING APPARATUS USED BY MEANS OF A RIGHT ANGLE OUTSIDE THE FOUNDRY HOUSE TO PUT ON THE TRANSPORT CART THE ROYAL EQUESTRIAN STATUE OF HIS MAJESTY KING JOSE I CAST IN ONE GO WITHOUT A FLAW IN THE ROYAL ROYAL ARTILLERY FOUNDRY HOUSE UNDER THE SUPERVISION OF LIEUTENANT GENERAL OF THE ROYAL ARTILERY OF THE KINGDOM MANOEL GOMES DE CARVOO E SILVA. INVENTED BY THE BRIGADIER BARTOLOMEO DA COSTA, THE FIRST TO FIND PORCELAIN IN PORTUGAL, AND HE DISCOVERED IT AT THE SAME TIME AS HE WAS DEVELOPING AND WORKING ON THE CASTING OF THE ROYAL STATUE
And in minute letters at the bottom:
GRAVADA NO ARCENAL R. DO EXERCITO. POR IOAQ. DE FIGUEIREDO
Chip to top of cresting, warped and slightly discoloured in firing
Exhibition Catalogue, ‘Portugal and Porcelain’, The Metropolitan Museum of Art, New York, November 19th, 1984 to February 3rd 1985