The business was afterwards carried on successively by “Chamberlain and Sons” and “Chamberlain and Co.” During the continuance of the two works it is believed that by far the greater part of the entire production of porcelain in the kingdom was made at Worcester; and certainly the books and the samples of various sets still remaining in the show-rooms bear evidence both of the high patronage and the extent of orders received, and of the beauty of workmanship which the proprietary had attained in their ware. The successive changes in the proprietary were as follows:--1786–1798, Robert Chamberlain, senior, Humphrey Chamberlain, and Richard Nash (sleeping partner); 1798–1804, Humphrey Chamberlain and Robert Chamberlain, junior; 1804–1811, the same, with G. E. Boulton as sleeping partner; 1811–1827, the same, without Boulton; 1828–1840, Walter Chamberlain and John Lilly. The marks then used, from 1840 to 1850, being _Chamberlain & Co., Worcester_, in writing italics, and CHAMBERLAIN’S in capital letters. In 1800, a third china manufactory was established in Worcester by Mr. Thomas Grainger, nephew of Humphrey Chamberlain, who had for many years taken an active and principal part in Chamberlain’s works. This establishment, of which a few words anon, is still continued by the son of its founder and partners under the firm of “G. Grainger and Co.” [Illustration: Fig. 538.] [Illustration: Figs. 539 to 545.--Productions of Messrs. Chamberlain, 1851.] The two principal manufactories, those of “Flight, Barr, and Barr,” and “Chamberlain and Co.,” continued until 1840, when they amalgamated, and the two firms formed one joint-stock company. The plant and stock were removed from Warmstry House to Messrs. Chamberlain’s premises, and the works were there carried on under the style of “Chamberlain and Co.” The mark used by Chamberlain and Co. was as follows:--