It is worthy of note that at this time, although much within the ten years stipulated for the partnership, the name of William Duesbury alone usually occurs. It is true that in some instances “Duesbury and Co.,” and “Duesbury and Heath,” are met with, but these are the exception. The works at Derby continued now rapidly to extend, and fresh articles and subjects were being continually added to those already made. The best available talent was got together, apprentices were taken to the modelling, the painting, the making or “repairing” of china, and other parts of the manufacture, and it was soon found advisable to have a regular warehouse in London. The mark used in the earliest days of the works is not certain, but I believe, and I have reason for that belief, that it was simply the letter D, which, would stand either for “Duesbury” or for “Derby;” probably in gold. The figures and groups, too, were numbered and registered for reproduction. On the 17th of August, 1769, Mr. Duesbury arranged for the purchase of the Chelsea China Works, their purchase being completed on the 5th of February, 1770, when a payment of £400, in part of the purchase-money, was made by Mr. Duesbury, who thus, as the proprietor of the Derby and the Chelsea Works, became the largest manufacturer in the kingdom.[10] The history of the Chelsea Works has already been fully given in the first volume of this work, and therefore it is only necessary here to say, that in 1862, in my paper on the Derby China Works, in the _Art Journal_, I was for the first time enabled to state the fact that Mr. Duesbury purchased “the Chelsea Porcelain Manufactory, and its appurtenances and lease thereof,” on the 5th of February, 1770, and that it was covenanted to be assigned over to him on or before the 8th of that month; the date of the arrangement to purchase being August 17th, 1769. For some few years, then, Mr. Duesbury carried on both establishments, and subsequently removed the models and some of the workmen to Derby, where also he removed such of the models, &c., from Bow, which had likewise come into his possession. The purchase of the Chelsea Works soon entailed upon him the commencement of some heavy law proceedings which lasted many years. The cause of these proceedings was the attempt at recovery of a quantity of goods claimed by Duesbury as a part of his purchase, being goods made by Spremont, and of his material, but which were afterwards sold, it was said, wrongfully, by Francis Thomas, to a person named Burnsall. The action was commenced in 1770, and in 1771 Mr. Spremont, the old proprietor of the Chelsea Works, died. The proceedings, however, continued for several years.