“The materials of which the body of the said porcellain is composed are a stone and earth, or clay. The stone is known in the countys of Devon and Cornwall by the names of Moor-stone and Growan, which stones are generally composed of grains of stone or gravel of a white or whitish colour, with a mixture of talky shining particles. This gravel and these talky particles are cemented together by a petrified clay into very solid rocks, and immense quantities of them are found in both the above-mentioned countys. All these stones, exposed to a violent fire, melt without the addition of fluxes into a semi-transparent glass, differing in clearness and beauty according to the purity of the stone. The earth, or clay, for the most part lies in the valleys where the stone forms the hills. This earth is very frequently very white, tho’ sometimes of a yellowish or cream colour. It generally arises with a large mixture of talky micæ, or spangles, and a semi-transparent or whitish gravel. Some sorts have little of the micæ, or spangles, but the best clay for making porcellain always abounds in micæ, or spangles. The stone is prepared by levigation in a potter’s mill, in water in the usual manner, to a very fine powder. The clay is prepared by diluting it with water untill the mixture is rendered sufficiently thin for the gravell and micæ to subside; the white water containing the clay is then poured, or left to run off from the subsided micæ and gravell into proper vessells or reservoirs; and after it has settled a day or two, the clear water above it is to be then poured or drawn off, and the clay, or earth, reduced to a proper consistence by the common methods of exposing it to the sun and air, or laying it on chalk. This earth, or clay, gives the ware its whiteness and infusibility, as the stone doth its transparency and mellowness: they are therefore to be mix’d in different proportions, as the ware is intended to be more or less transparent; and the mixture is to be performed in the method used by potters, and well known (viz., by diluting the materials in water, passing the mixture through a fine sieve, and reducing it to a paste of a proper consistence for working in the way directed for the preparation of the clay). This paste is to be form’d into vessells, and these vessells, when biscuited, are to be dipp’d in the glaze, which is prepared of the levigated stone, with the addition of lime and fern-ashes, or an earth called magnesia alba, in such quantity as may make it properly fusible and transparent when it has received a due degree of fire in the second baking.

“In witness whereof I, the said William Cookworthy, have hereunto sett my hand and seal this Eleventh day of July, in the Eighth year of the reign of our Sovereign Lord George the Third, by the grace of God of Great Britain, France, and Ireland, King, Defender of the Faith, and so forth, and in the year of our Lord One Thousand Seven Hundred and Sixty-eight.

“William (l. s.) Cookworthy.

“Signed, sealed, and delivered by the within-named William Cookworthy, in the presence of

“And be it remembered that on aforesaid Eleventh day of July, in the year above-mentioned, the aforesaid William Cookworthy came before our said Lord the King in his Chancery, and acknowledged the Specification aforesaid, and all and everything therein contained and specified in form above written. And also the Specification aforesaid was stampt according to the tenor of the statute made in the sixth year of the reign of the late King and Queen William and Mary of England, and so forth.

“Inrolled the Fourteenth day of July, in the year above written.

“Samuel Champion, a Master Extraordinary.”

It is natural to suppose that the finest and best goods of the Plymouth Works were produced in the six years which intervened between the enrolling of this specification and the removal of the Works to Bristol, previous to their sale to Champion. The progress of the manufactory had hitherto been great and satisfactory, but continuing at the same rate of improvement, the perfection to which the best productions arrived could only have been attained a very short time before its close.

Cookworthy determined to make his porcelain equal to that of Sèvres and Dresden, both in body, which he himself mixed, and in ornamentation, for which he procured the services of such artists as were available. To this end he engaged a Mon. Saqui, or Soqui, from Sèvres, who was a man of rare talent as a painter and enameller, and to whose hands, and those of Henry Bone, a native of Plymouth, who there is reason to suppose was apprenticed to Cookworthy, and afterwards became very celebrated, the best painted specimens may be ascribed. Besides these several other artists were employed, but they were principally engaged in painting in blue, while Saqui and Bone painted the high-class birds and flowers.